Substrate processing device and substrate processing method

Abstract

This substrate processing device 1 comprises: a water flow path for guiding water toward a substrate W; and a solvent flow path 33x for guiding an organic solvent, which is a liquid having a lower surface tension than water, toward the substrate W. The water flow path includes an uneven surface 72 including a recess 72u, at least a part of which is filled with air, and a protrusion 72h in contact with water in contact with the air in the recess 72u. The solvent flow path 33x includes a mirror surface 71 in contact with the organic solvent.

Description

Substrate processing apparatus and substrate processing method Related Applications

[0001] This application claims priority based on Japanese Patent Application No. 2023-159045 filed on September 22, 2023, and Japanese Patent Application No. 2024-043839 filed on March 19, 2024, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a substrate processing apparatus and a substrate processing method for processing substrates, including, for example, semiconductor wafers, substrates for FPDs (Flat Panel Displays) such as liquid crystal display devices and organic EL (electroluminescence) display devices, substrates for optical disks, substrates for magnetic disks, substrates for magneto-optical disks, substrates for photomasks, ceramic substrates, and substrates for solar cells.

[0003] Japanese Patent Application Laid-Open No. 2003-144222 discloses that pipes in a substrate processing apparatus installed in a factory are cleaned with a cleaning liquid before the apparatus is put into use.

[0004] Japanese Patent Application Laid-Open No. 2020-155649

[0005] Since substrates cannot be processed in the substrate processing apparatus while the pipes are being cleaned, it is preferable to clean the members that form the flow paths, such as the pipes, for a short period of time. It is also preferable to clean the members infrequently.

[0006] An embodiment of the present invention provides a substrate processing apparatus and a substrate processing method that can reduce the time required to clean a flow path that guides a processing liquid to be supplied to a substrate.

[0007] Furthermore, one embodiment of the present invention provides a substrate processing apparatus and a substrate processing method that can reduce the frequency of cleaning a flow path that guides a processing liquid to be supplied to a substrate.

[0008] One embodiment of the present invention provides a substrate processing apparatus comprising: a substrate holder for holding a substrate; a water flow path for guiding water toward the substrate held in the substrate holder; and a solvent flow path for guiding an organic solvent, which is a liquid with a lower surface tension than water, toward the substrate held in the substrate holder, wherein the water flow path includes an uneven surface including a recess at least partially filled with air and a protrusion in contact with the water that is in contact with the air in the recess, and the solvent flow path includes a mirror surface in contact with the organic solvent.

[0009] In the above embodiment, at least one of the following features may be added to the substrate processing apparatus.

[0010] The uneven surface is made of a fluororesin.

[0011] The water flow path includes a water tank that stores the water and a water pipe that guides the water supplied from the water tank, and the uneven surface is provided on the inner surface of the water tank.

[0012] The solvent flow path includes a solvent tank that stores the organic solvent and a solvent pipe that guides the organic solvent supplied from the solvent tank, and the mirror surface is provided on the inner surface of the solvent tank.

[0013] The uneven surface is provided at a bent portion of the water flow path.

[0014] The substrate processing apparatus further includes a high-temperature chemical flow path that guides a high-temperature chemical liquid that is hotter than room temperature toward the substrate held in the substrate holder, and the high-temperature chemical flow path includes an uneven surface that includes a recess at least partially filled with air and a protrusion that contacts the high-temperature chemical liquid that contacts the air in the recess.

[0015] The uneven surface of the high-temperature chemical liquid flow path is made of a fluororesin.

[0016] The high-temperature chemical liquid flow path includes a high-temperature chemical liquid tank that stores the high-temperature chemical liquid, and a high-temperature chemical liquid piping that guides the high-temperature chemical liquid supplied from the high-temperature chemical liquid tank, and the uneven surface of the high-temperature chemical liquid flow path is provided on the inner surface of the high-temperature chemical liquid tank.

[0017] The high-temperature chemical flow path includes a high-temperature chemical pipe that guides the high-temperature chemical, and a high-temperature chemical nozzle that discharges the high-temperature chemical guided by the high-temperature chemical pipe, and the uneven surface of the high-temperature chemical flow path is provided on the inner surface of the high-temperature chemical nozzle.

[0018] The uneven surface is provided at the bent portion of the high-temperature chemical liquid flow path.

[0019] Another embodiment of the present invention provides a substrate processing method including: a water supplying step of guiding water toward a substrate held by a substrate holder through a water flow path including the uneven surface, in a state in which at least a portion of the recesses of the uneven surface are filled with air and the protrusions of the uneven surface are in contact with water that is in contact with the air in the recesses; and a solvent supplying step of guiding an organic solvent, which is a liquid having a surface tension lower than that of water, toward the substrate held by the substrate holder through a solvent flow path including the mirror surface, before or after the water supplying step, in a state in which the mirror surface is in contact with the organic solvent. The following features may be added to this embodiment, and at least one of the features described above regarding the substrate processing apparatus may also be added to the substrate processing method.

[0020] The substrate processing method further includes a high-temperature chemical supplying step of guiding a high-temperature chemical solution that is hotter than room temperature toward the substrate held in a substrate holder, and the high-temperature chemical supplying step includes a step of circulating the high-temperature chemical solution through a high-temperature chemical solution flow path that includes the uneven surface in a state in which at least a portion of the recesses of the uneven surface are filled with air and the convex portions of the uneven surface are in contact with the high-temperature chemical solution that is in contact with the air in the recesses.

[0021] Yet another embodiment of the present invention provides a substrate processing apparatus comprising: a substrate holder for holding a substrate; and a high-temperature chemical flow path for guiding a high-temperature chemical liquid that is hotter than room temperature toward the substrate held in the substrate holder, wherein the high-temperature chemical flow path includes an uneven surface that includes a recess at least partially filled with air and a protrusion in contact with the high-temperature chemical liquid that is in contact with the air in the recess.

[0022] In the above embodiment, at least one of the following features may be added to the substrate processing apparatus.

[0023] The substrate processing apparatus further includes a solvent flow path that guides an organic solvent, which is a liquid with a lower surface tension than the high-temperature chemical liquid, toward the substrate held by the substrate holder, and the solvent flow path includes a mirror surface that comes into contact with the organic solvent.

[0024] The uneven surface is made of a fluororesin.

[0025] The high-temperature chemical flow path includes a high-temperature chemical tank that stores the high-temperature chemical, and a high-temperature chemical pipe that guides the high-temperature chemical supplied from the high-temperature chemical tank, and the uneven surface is provided on the inner surface of the high-temperature chemical tank.

[0026] The high-temperature chemical flow path includes a high-temperature chemical pipe that guides the high-temperature chemical, and a high-temperature chemical nozzle that discharges the high-temperature chemical guided by the high-temperature chemical pipe, and the uneven surface is provided on the inner surface of the high-temperature chemical nozzle.

[0027] The uneven surface is provided at the bent portion of the high-temperature chemical liquid flow path.

[0028] Yet another embodiment of the present invention provides a substrate processing method, comprising: a high-temperature chemical supplying step of guiding a high-temperature chemical liquid, the high-temperature chemical liquid being higher than room temperature, toward a substrate held by a substrate holder, the high-temperature chemical supplying step including a step of circulating the high-temperature chemical liquid through a high-temperature chemical flow path including the uneven surface, in a state in which at least a portion of the recesses of the uneven surface are filled with air and the convex portions of the uneven surface are in contact with the high-temperature chemical liquid that is in contact with the air in the recesses. The following features may be added to this embodiment, and at least one of the features described above regarding the substrate processing apparatus may also be added to the substrate processing method.

[0029] The substrate processing method further includes a solvent supplying step in which, before or after the high-temperature chemical supplying step, the organic solvent is guided toward the substrate held in the substrate holder by a solvent flow path including the mirror surface, while the mirror surface is in contact with an organic solvent, which is a liquid having a surface tension lower than that of the high-temperature chemical liquid.

[0030] The above and other objects, features and advantages of the present invention will become apparent from the following description of the embodiments with reference to the accompanying drawings.

[0031] 15A and 15B are schematic plan views showing the layout of a substrate processing apparatus according to an embodiment of the present invention; a schematic side view of the substrate processing apparatus; a schematic horizontal view of the interior of a processing unit provided in the substrate processing apparatus; a block diagram showing the electrical configuration of the substrate processing apparatus; a process diagram for explaining an example of substrate processing performed by the substrate processing apparatus; a schematic view of a processing liquid supply system of a substrate processing apparatus that supplies a processing liquid to a substrate; a schematic cross-sectional view showing an example of a droplet contacting a smooth surface; a schematic cross-sectional view showing an example of a droplet contacting a rough surface in a Wenzel state; a schematic cross-sectional view showing an example of a droplet contacting a rough surface in a Cassie-Baxter state; a schematic cross-sectional view showing an example of an interface between a liquid contact portion and a liquid; a schematic view showing an example of a cross-section of a bent portion of a chemical liquid pipe; a schematic view showing an example of a cross-section of a bent portion taken along line XI-XI shown in FIG. 10; a schematic view showing an example of a cross-section of a mold for manufacturing a chemical liquid pipe; a schematic view showing an example of a cross-section of a mold taken along line XIII-XIII shown in FIG. 12; a schematic cross-sectional view showing a substrate processing apparatus according to another embodiment of the present invention; a schematic view showing another configuration example of a processing unit provided in the substrate processing apparatus; and a process diagram for explaining an example of substrate processing using the processing unit of FIG. 15A and 15B. 1 is a schematic diagram of a supply system for a processing liquid containing a high-temperature chemical liquid;

[0032] 1A is a schematic plan view showing the layout of a substrate processing apparatus 1 according to an embodiment of the present invention, and FIG.

[0033] The substrate processing apparatus 1 is a single-wafer processing apparatus that processes disk-shaped substrates W such as semiconductor wafers one by one. The substrate processing apparatus 1 includes a load port LP that holds carriers CA that accommodate substrates W, a plurality of processing units 2 that process the substrates W transferred from the carriers CA on the load port LP with processing fluids such as processing liquids and processing gases, a transport system TS that transports the substrates W between the carriers CA on the load port LP and the plurality of processing units 2, and a control device 3 that controls the substrate processing apparatus 1.

[0034] The multiple processing units 2 form multiple towers TW. Fig. 1A shows an example in which four towers TW are formed. As shown in Fig. 1B, the multiple processing units 2 included in one tower TW are stacked one above the other. As shown in Fig. 1A, the multiple towers TW form two rows extending in the depth direction of the substrate processing apparatus 1 in a plan view. In a plan view, the two rows face each other across a transport path TP.

[0035] The transport system TS includes an indexer robot IR that transports substrates W between a carrier CA on a load port LP and the plurality of processing units 2, and a center robot CR that transports substrates W between the indexer robot IR and the plurality of processing units 2. The indexer robot IR is disposed between the load port LP and the center robot CR in a plan view. The center robot CR is disposed on the transport path TP.

[0036] The indexer robot IR includes one or more hands Hi that horizontally support a substrate W. The hands Hi can move parallel to both the horizontal and vertical directions. The hands Hi can rotate about a vertical line. The hands Hi can load and unload a substrate W into and from a carrier CA on any of the load ports LP, and can transfer a substrate W to and from the center robot CR.

[0037] The center robot CR includes one or more hands Hc that horizontally support a substrate W. The hands Hc can move parallel to both the horizontal and vertical directions. The hands Hc can rotate about a vertical line. The hands Hc can transfer substrates W to and from the indexer robot IR, and can transport substrates W into and out of any of the processing units 2.

[0038] Next, the processing unit 2 will be described.

[0039] 2 is a horizontal schematic diagram of the interior of a processing unit 2 provided in the substrate processing apparatus 1. The processing unit 2 includes a box-shaped chamber 4 having an internal space, a spin chuck 10 that holds one substrate W horizontally in the chamber 4 and rotates the substrate W about a vertical rotation axis A1 passing through the center of the substrate W, and a cylindrical processing cup 21 that surrounds the spin chuck 10 about the rotation axis A1.

[0040] The chamber 4 includes a box-shaped partition 5 provided with an inlet / outlet port 5b through which the substrate W passes, and a door 7 for opening and closing the inlet / outlet port 5b. An FFU 6 (fan filter unit) is disposed above an air outlet 5a disposed at the top of the partition 5. The FFU 6 constantly supplies clean air (air filtered by a filter) into the chamber 4 through the air outlet 5a. The gas within the chamber 4 is exhausted from the chamber 4 through an exhaust duct 8 connected to the bottom of the processing cup 21. This constantly creates a downflow of clean air within the chamber 4. The flow rate of the exhaust gas discharged into the exhaust duct 8 is changed depending on the opening degree of an exhaust valve 9 disposed in the exhaust duct 8.

[0041] The spin chuck 10 includes a disk-shaped spin base 12 held horizontally, a plurality of chuck pins 11 that hold the substrate W horizontally above the spin base 12, a spin shaft 13 that extends downward from the center of the spin base 12, and a spin motor 14 that rotates the spin shaft 13 to rotate the spin base 12 and the plurality of chuck pins 11.

[0042] The spin chuck 10 is not limited to a clamping type chuck in which multiple chuck pins 11 contact the edge surface of the substrate W, but may also be a vacuum type chuck that holds the substrate W horizontally by adsorbing the back surface (lower surface) of the substrate W, which is not a device formation surface, to the upper surface 12u of the spin base 12. When the spin chuck 10 is a clamping type chuck, the multiple chuck pins 11 correspond to the substrate holder. When the spin chuck 10 is a vacuum type chuck, the spin base 12 corresponds to the substrate holder.

[0043] The processing cup 21 includes a plurality of guards 24 that receive the processing liquid discharged outward from the substrate W, a plurality of cups 23 that receive the processing liquid guided downward by the plurality of guards 24, and a cylindrical outer wall member 22 that surrounds the plurality of guards 24 and the plurality of cups 23. Figure 2 shows an example in which four guards 24 and three cups 23 are provided, and the outermost cup 23 is integrated with the third guard 24 from the top.

[0044] The guard 24 includes a cylindrical portion 25 surrounding the spin chuck 10 and an annular ceiling portion 26 extending obliquely upward from the upper end of the cylindrical portion 25 toward the rotation axis A1. The multiple ceiling portions 26 are stacked one on top of the other, and the multiple cylindrical portions 25 are arranged concentrically. The upper end of the annular ceiling portion 26 corresponds to an upper end 24u of the guard 24 surrounding the substrate W and the spin base 12 in a plan view. The multiple cups 23 are respectively arranged below the multiple cylindrical portions 25. The cups 23 form annular grooves that receive the processing liquid guided downward by the guard 24.

[0045] The processing unit 2 includes a guard lifting unit 27 that individually lifts and lowers the multiple guards 24. The guard lifting unit 27 positions the guards 24 at any position within a range from the upper position to the lower position. Fig. 2 shows a state in which two guards 24 are positioned at the upper position and the remaining two guards 24 are positioned at the lower position. The upper position is a position in which the upper ends 24u of the guards 24 are positioned above the holding position in which the substrate W held by the spin chuck 10 is positioned. The lower position is a position in which the upper ends 24u of the guards 24 are positioned below the holding position.

[0046] The processing unit 2 includes a plurality of nozzles that discharge processing fluids toward the substrate W held on the spin chuck 10. The plurality of nozzles includes a chemical liquid nozzle 31 that discharges a chemical liquid toward the upper surface of the substrate W, and a rinse liquid nozzle 32 that discharges a rinse liquid toward the upper surface of the substrate W. The plurality of nozzles further includes a solvent nozzle 33 that discharges an organic solvent toward the upper surface of the substrate W. FIG. 2 shows an example in which the rinse liquid nozzle 32 discharges DIW (deionized water), and the solvent nozzle 33 discharges IPA (isopropyl alcohol). DIW stands for pure water (deionized water). Unless otherwise specified, organic solvent refers to a liquid organic solvent. The same applies to IPA.

[0047] The chemical nozzle 31 is connected to a chemical pipe 31p that guides the chemical. When a chemical valve 31v attached to the chemical pipe 31p is opened, the chemical is continuously discharged downward from a discharge port 31d of the chemical nozzle 31. The chemical may be a liquid containing at least one of sulfuric acid, nitric acid, hydrochloric acid, hydrofluoric acid, phosphoric acid, acetic acid, ammonia water, hydrogen peroxide, an organic acid (e.g., citric acid, oxalic acid, etc.), an organic alkali (e.g., TMAH: tetramethylammonium hydroxide, etc.), a surfactant, and a corrosion inhibitor, or may be another liquid.

[0048] Although not shown, the chemical liquid valve 31v includes a valve body with an annular valve seat through which the chemical liquid passes, a valve element that is movable relative to the valve seat, and an actuator that moves the valve element between a closed position in which the valve element contacts the valve seat and an open position in which the valve element is separated from the valve seat. The same applies to the other valves. The actuator may be a pneumatic actuator, an electric actuator, or another type of actuator. The control device 3 controls the actuator to open and close the chemical liquid valve 31v, etc.

[0049] The rinse liquid nozzle 32 is connected to a rinse liquid pipe 32p that guides the rinse liquid. When a rinse liquid valve 32v attached to the rinse liquid pipe 32p is opened, the rinse liquid is continuously discharged downward from a discharge port 32d of the rinse liquid nozzle 32. The rinse liquid may be any of pure water, carbonated water, electrolytic ion water, hydrogen water, ozone water, and hydrochloric acid water with a diluted concentration (for example, about 10 to 100 ppm), or may be any other liquid.

[0050] The solvent nozzle 33 is connected to a solvent pipe 33p that guides the organic solvent. When a solvent valve 33v attached to the solvent pipe 33p is opened, the organic solvent is continuously discharged downward from a discharge port 33d of the solvent nozzle 33. The organic solvent may be an alcohol other than IPA, or an organic solvent other than alcohol, such as HFE (hydrofluoroether). IPA has a higher vapor pressure and a lower surface tension than water.

[0051] The chemical liquid nozzle 31 may be a scan nozzle that moves the collision position of the chemical liquid on the substrate W within the upper surface of the substrate W, or may be a fixed nozzle that cannot move the collision position of the chemical liquid on the substrate W. The same applies to the other nozzles. Figure 2 shows an example in which the chemical liquid nozzle 31 and the solvent nozzle 33 are scan nozzles and the rinse liquid nozzle 32 is a fixed nozzle.

[0052] Chemical nozzle 31 is connected to a nozzle moving unit 31m that moves chemical nozzle 31 in at least one of the vertical and horizontal directions. Nozzle moving unit 31m moves chemical nozzle 31 horizontally between a processing position (position shown in FIG. 2 ) where the chemical solution ejected from chemical nozzle 31 is supplied to the upper surface of substrate W, and a standby position where chemical nozzle 31 is positioned around processing cup 21 in a plan view.

[0053] The solvent nozzle 33 is connected to a nozzle moving unit 33m that moves the solvent nozzle 33 in at least one of the vertical and horizontal directions. The nozzle moving unit 33m moves the solvent nozzle 33 horizontally between a processing position (position shown in FIG. 2 ) where the organic solvent discharged from the solvent nozzle 33 is supplied to the upper surface of the substrate W and a standby position where the solvent nozzle 33 is positioned around the processing cup 21 in a plan view.

[0054] Next, the electrical configuration of the substrate processing apparatus 1 will be described.

[0055] 3 is a block diagram showing the electrical configuration of the substrate processing apparatus 1. The control device 3 includes at least one computer. The computer includes a computer main body 3a and a peripheral device 3d connected to the computer main body 3a. The computer main body 3a includes a CPU 3b (central processing unit) that executes various instructions and a memory 3c that stores information. The peripheral device 3d includes a storage 3e that stores information to be transmitted and received between the memory 3c, such as a program P, a reader 3f that reads information from removable media RM, and a communication device 3g that communicates with other devices, such as a host computer. The memory 3c and the storage 3e are both examples of storage devices that store information to be transmitted and received between the CPU 3b and the peripheral device 3d.

[0056] The control device 3 is connected to an input device and a display device. The input device is operated when an operator such as a user or a maintenance technician inputs information into the substrate processing apparatus 1. The information is displayed on the screen of the display device. The input device may be any of a keyboard, a pointing device, and a touch panel, or may be other devices. The substrate processing apparatus 1 may be provided with a touch panel display that serves as both an input device and a display device.

[0057] The CPU 3b executes a program P stored in the storage 3e. The program P in the storage 3e may be one that has been pre-installed in the control device 3, one that has been sent from a removable medium RM to the storage 3e via the reader 3f, or one that has been sent from an external device such as a host computer to the storage 3e via the communication device 3g.

[0058] The memory 3c is a volatile memory that retains its memory only when power is supplied. The storage 3e and the removable medium RM are non-volatile memories that retain their memory even when power is not supplied. The storage 3e is, for example, a magnetic storage device such as a hard disk drive. The removable medium RM is, for example, an optical disk such as a compact disk or a semiconductor memory such as a memory card. The removable medium RM is an example of a computer-readable recording medium on which the program P is recorded. The removable medium RM is a non-transitory tangible recording medium.

[0059] The storage 3e stores a plurality of recipes. A recipe is information that defines the processing content, processing conditions, and processing procedure of a substrate W. The plurality of recipes differ from one another in at least one of the processing content, processing conditions, and processing procedure of a substrate W. The control device 3 controls the substrate processing apparatus 1 so that the substrate W is processed in accordance with the recipe specified by the host computer. The control device 3 is programmed to execute the following steps.

[0060] Next, an example of processing of the substrate W will be described.

[0061] 4 is a process diagram for explaining an example of processing of a substrate W performed by the substrate processing apparatus 1. In the following, reference will be made to FIGS. 1A, 2, and 4.

[0062] When a substrate W is to be processed, the indexer robot IR takes the substrate W out of the carrier CA on one of the load ports LP. The center robot CR carries the substrate W taken out by the indexer robot IR into one of the processing units 2 and places it on the spin chuck 10. Thereafter, a plurality of chuck pins 11 are pressed horizontally against the edge surface of the substrate W, and the spin motor 14 starts to rotate. This starts the rotation of the substrate W.

[0063] When the substrate W starts to rotate, the chemical valve 31v is opened, and the chemical nozzle 31 discharges the chemical toward the upper surface of the rotating substrate W. This forms a film of the chemical that covers the entire upper surface of the substrate W (step S1 in FIG. 4: an example of a water supply step). While the chemical nozzle 31 is discharging the chemical, the nozzle moving unit 31m may move the chemical nozzle 31 so that the collision position of the chemical against the upper surface of the substrate W passes through the center and the outer periphery, or may keep the chemical nozzle 31 stationary so that the collision position remains stationary at the center. Whether or not the collision position is moved applies similarly to other processing liquids.

[0064] When a predetermined time has elapsed since the chemical liquid valve 31v was opened, the chemical liquid valve 31v is closed and the rinse liquid valve 32v is opened. In response, the rinse liquid nozzle 32 ejects pure water, an example of a rinse liquid, toward the upper surface of the rotating substrate W. As a result, the chemical liquid on the substrate W is replaced with the pure water, and a liquid film of pure water is formed covering the entire upper surface of the substrate W (step S2 in FIG. 4 : an example of a water supply process). Thereafter, the rinse liquid valve 32v is closed and the solvent valve 33v is opened. In response, the solvent nozzle 33 ejects IPA, an example of an organic solvent, toward the upper surface of the rotating substrate W. As a result, the pure water on the substrate W is replaced with IPA, and a liquid film of IPA is formed covering the entire upper surface of the substrate W (step S3 in FIG. 4 : an example of a solvent supply process). Thereafter, the solvent valve 33v is closed.

[0065] When the solvent valve 33v is closed, the spin motor 14 rotates the substrate W held by the chuck pins 11 at a high rotational speed (e.g., several thousand rpm). This removes the liquid from the substrate W and dries the substrate W (step S4 in FIG. 4). After the substrate W has dried, the spin motor 14 stops and the chuck pins 11 move away from the edge of the substrate W. This stops the rotation of the substrate W and releases the substrate W from its hold. The center robot CR then unloads the substrate W from the processing unit 2. The indexer robot IR loads the substrate W unloaded by the center robot CR into a carrier CA on one of the load ports LP.

[0066] In this way, one substrate W is treated with a treatment liquid such as a chemical liquid or a rinse liquid. The control device 3 controls the indexer robot IR and the like to cause the substrate treatment apparatus 1 to repeat the above-described series of operations. In this way, a plurality of substrates W are treated one by one.

[0067] Next, a processing liquid supply system of the substrate processing apparatus 1 will be described.

[0068] 5A is a schematic diagram of a chemical liquid supply system of a substrate processing apparatus 1 that supplies a chemical liquid to a substrate W. The substrate processing apparatus 1 includes a chemical liquid nozzle 31, a chemical liquid pipe 31p, and a chemical liquid valve 31v, as well as a chemical liquid tank 31t that stores the chemical liquid to be supplied to the chemical liquid nozzle 31. The substrate processing apparatus 1 further includes a chemical liquid pump 31P that sends the chemical liquid in the chemical liquid tank 31t toward the chemical liquid nozzle 31, and a chemical liquid filter 31F that removes foreign matter from the chemical liquid sent out from the chemical liquid tank 31t. The upstream end of the chemical liquid pipe 31p is connected to the chemical liquid tank 31t. The downstream end of the chemical liquid pipe 31p is connected to the chemical liquid nozzle 31.

[0069] 5B is a schematic diagram of a solvent supply system of the substrate processing apparatus 1 that supplies an organic solvent to a substrate W. In addition to the solvent nozzle 33, the solvent pipe 33p, and the solvent valve 33v, the substrate processing apparatus 1 includes a solvent tank 33t that stores the organic solvent to be supplied to the solvent nozzle 33. The substrate processing apparatus 1 further includes a solvent pump 33P that sends the organic solvent in the solvent tank 33t toward the solvent nozzle 33, and a solvent filter 33F that removes foreign matter from the organic solvent sent out from the solvent tank 33t. The upstream end of the solvent pipe 33p is connected to the solvent tank 33t. The downstream end of the solvent pipe 33p is connected to the solvent nozzle 33.

[0070] The chemical solution is an aqueous solution of chemicals. "H2O" in FIG. 5A represents water contained in the chemical solution. The surface tension of the chemical solution is the same as or nearly the same as the surface tension of water (H2O). The surface tension of the chemical solution is higher than the surface tension of organic solvents such as IPA. In the following description, unless otherwise specified, water refers to a liquid with a water (H2O) concentration of 100% or nearly 100%, or a liquid with a surface tension equal to or nearly equal to the surface tension of water (H2O). As long as these conditions are met, water may contain substances other than water (H2O). A rinse liquid such as pure water is an example of water. The chemical solution is another example of water.

[0071] An organic solvent is a liquid with a surface tension lower than that of water (H2O). As long as the organic solvent has a surface tension lower than that of water (H2O), it may be a liquid of one substance or a liquid containing multiple substances. In the latter case, the organic solvent may contain water (H2O). The organic solvent may be a liquid such that, when the organic solvent is brought into contact with the uneven surface 72 described below, the recesses 72u are filled with the organic solvent and the protrusions 72h come into contact with the organic solvent. Hereinafter, water and organic solvent may be collectively referred to as the treatment liquid.

[0072] The path through which the chemical liquid passes before being discharged from the discharge port 31d of the chemical liquid nozzle 31 corresponds to one continuous chemical liquid flow path 31x extending from the start position to the goal position. The path through which the organic solvent passes before being discharged from the discharge port 33d of the solvent nozzle 33 corresponds to one continuous solvent flow path 33x extending from the start position to the goal position. Although not shown, the path through which the rinse liquid passes before being discharged from the discharge port 32d of the rinse liquid nozzle 32 corresponds to one continuous rinse liquid flow path extending from the start position to the goal position.

[0073] The chemical liquid flow path 31x is an example of a single water flow path that is continuous from the start position to the goal position. The rinse liquid flow path is also an example of a water flow path. The structure of the rinse liquid flow path is similar to that of the chemical liquid flow path 31x, except that pure water is supplied from utility piping installed in the factory where the substrate processing apparatus 1 is installed, rather than from a tank such as the chemical liquid tank 31t. Therefore, a description of the rinse liquid flow path will be omitted below.

[0074] Chemical tank 31t corresponds to the start position of chemical flow path 31x. Discharge outlet 31d of chemical nozzle 31 corresponds to the goal position of chemical flow path 31x. Similarly, solvent tank 33t corresponds to the start position of solvent flow path 33x. Discharge outlet 33d of solvent nozzle 33 corresponds to the goal position of solvent flow path 33x. When a processing liquid is supplied to chemical flow path 31x or solvent flow path 33x from a utility pipe provided in a factory where substrate processing apparatus 1 is installed, the start position may not be chemical tank 31t or solvent tank 33t, but may be the upstream end of chemical pipe 31p or solvent pipe 33p, or may be a joint connecting chemical pipe 31p or solvent pipe 33p to the utility pipe.

[0075] There may be only one start position per chemical liquid flow path 31x, or multiple start positions per chemical liquid flow path 31x. Similarly, there may be only one goal position per chemical liquid flow path 31x, or multiple goal positions per chemical liquid flow path 31x. For example, a treatment liquid supplied from one start position may be ejected from multiple goal positions. When ejecting a mixture of a first component liquid and a second component liquid, the chemical liquid flow path 31x may include a start position for the first component liquid, a start position for the second component liquid, and one or more goal positions for ejecting the first component liquid and the second component liquid mixed downstream of the two start positions. The same applies to the start position and goal position of the solvent flow path 33x.

[0076] Chemical solution flow path 31x includes chemical solution nozzle 31 provided with discharge port 31d for discharging the chemical solution, and chemical solution piping 31p for guiding the chemical solution toward chemical solution nozzle 31. Chemical solution flow path 31x may further include fluid devices other than chemical solution nozzle 31 and chemical solution piping 31p.

[0077] Specifically, instead of or in addition to at least one of the chemical valve 31v, the chemical tank 31t, the chemical pump 31P, and the chemical filter 31F, the chemical flow path 31x may further include at least one of a circulation pipe that circulates the chemical liquid in the chemical tank 31t upstream of the chemical pipe 31p, a flow control valve that changes the flow rate of the chemical liquid supplied to the chemical nozzle 31, a flow meter that measures the flow rate of the chemical liquid supplied to the chemical nozzle 31, a fitting that connects two or more pipes, a manifold that connects three or more pipes, a heater that heats the chemical liquid, and a cooler that cools the chemical liquid.

[0078] Similar to the chemical solution flow path 31x, the solvent flow path 33x includes a solvent nozzle 33 provided with a discharge port 33d for discharging the organic solvent, and a solvent pipe 33p for guiding the organic solvent toward the solvent nozzle 33. The solvent flow path 33x may further include fluidic devices other than the solvent nozzle 33 and the solvent pipe 33p, such as a solvent valve 33v. Specific examples of the fluidic devices are the same as those described above.

[0079] The liquid medicine flow path 31x includes an internal space in which a flowing or stationary liquid medicine is placed, and a cylindrical inner surface 31y that surrounds the entire periphery of the internal space. The internal space of the liquid medicine flow path 31x is an enclosed space that is open only at the goal position of the liquid medicine flow path 31x. In other words, the internal space of the liquid medicine flow path 31x is in contact with the space outside the liquid medicine flow path 31x only at the goal position of the liquid medicine flow path 31x.

[0080] Similar to the chemical flow path 31x, the solvent flow path 33x includes an internal space in which a flowing or stationary organic solvent is disposed, and a cylindrical inner surface 33y that surrounds the entire periphery of the internal space. The internal space of the solvent flow path 33x is a sealed space that is open only at the goal position of the solvent flow path 33x. In other words, the internal space of the solvent flow path 33x is in contact with the space outside the solvent flow path 33x only at the goal position of the solvent flow path 33x.

[0081] The inner surface 31y of the chemical flow path 31x and the inner surface 33y of the solvent flow path 33x are made of a resin such as a fluororesin. The fluororesin may be PTFE (Polytetrafluoroethylene) or PFA (Perfluoroalkoxyalkane), or may be other materials. The entire inner surface 31y of the chemical flow path 31x may be made of the same material, or a portion of the inner surface 31y of the chemical flow path 31x may be made of a different material from the remaining portion of the inner surface 31y of the chemical flow path 31x. The same applies to the inner surface 33y of the solvent flow path 33x.

[0082] As shown enlarged on the right side of Fig. 5B, the inner surface 33y of the solvent flow path 33x includes a mirror surface 71 that contacts the organic solvent in the solvent flow path 33x. The mirror surface 71 is a surface that has been subjected to a mirror finish to reduce surface roughness. The mirror finish may be polishing or another method.

[0083] 5A , inner surface 31y of chemical solution flow path 31x includes an uneven surface 72 that comes into contact with the chemical solution in chemical solution flow path 31x. Uneven surface 72 is a rough surface having a greater surface roughness than mirror surface 71. In other words, mirror surface 71 is a smooth surface having a smaller surface roughness than uneven surface 72.

[0084] The entire inner surface 31y of the chemical liquid flow path 31x may be the uneven surface 72, or only a portion of the inner surface 31y of the chemical liquid flow path 31x may be the uneven surface 72. The same applies to the mirror surface 71. Fig. 5A shows an example in which all or a portion of the inner surface of the chemical liquid tank 31t is the uneven surface 72. Fig. 5B shows an example in which all or a portion of the inner surface of the solvent tank 33t is the mirror surface 71.

[0085] The uneven surface 72 is a water-repellent surface that has been subjected to a water-repellent treatment that increases the contact angle of water with chemical solutions, rinse solutions, etc. The water-repellent treatment may be at least one of cutting, laser processing, plastic processing, extrusion molding, blasting, and etching, or may be other than these.

[0086] The cutting process may be at least one of lathe processing and milling processing, or may be other processes. The blasting process is a process in which solid particles are collided with the surface of an object (such as shot blasting). The etching process is a process in which the surface of an object is corroded with a chemical. The water-repellent process may be a process in which the irregularities on the surface of a mold are transferred to the object. In this case, the water-repellent process may be at least one of plastic processing and extrusion molding, or may be other processes.

[0087] As shown in Figure 5A, the uneven surface 72 is a solid surface provided with a plurality of recesses 72u and a plurality of protrusions 72h. The recesses 72u are recessed from the tips 72d of the protrusions 72h. The protrusions 72h protrude from the bottoms 72b of the recesses 72u. The bottoms 72b of the recesses 72u correspond to the bases of the protrusions 72h. The tips 72d of the protrusions 72h correspond to the opening ends of the recesses 72u. The tips 72d of two adjacent protrusions 72h form the entrance of the recess 72u located between them.

[0088] The convex portion 72h may be linear with a depth greater than its width, or may be dot-shaped with a depth equal to or approximately equal to its width, or may have other shapes. The same applies to the concave portion 72u. The cross-section of the convex portion 72h may be rectangular, square, triangular, inverted triangle, trapezoid, inverted trapezoid, or semicircular, or may have other shapes. The same applies to the cross-section of the concave portion 72u. FIG. 5A shows an example in which the cross-sections of the convex portion 72h and the concave portion 72u are rectangular. The height of the convex portion 72h (the length in the left-right direction in FIG. 5A) may be uniform or non-uniform. The same applies to the depth of the concave portion 72u. The height of the convex portion 72h may be equal to or different from the width of the convex portion 72h (the length in the up-down direction in FIG. 5A). The depth of the concave portion 72u may be equal to or different from the width of the concave portion 72u.

[0089] When the water contact angle is less than 90 degrees, the solid surface is said to be hydrophilic. When the water contact angle is 90 degrees or more, the solid surface is said to be water-repellent or hydrophobic. When the water contact angle is 150 degrees or more, the solid surface is said to be super-water-repellent. The water contact angle with a smooth surface made of fluororesin may be greater than 90 degrees or less than 90 degrees. The water contact angle with a smooth surface made of PTFE is said to be 104 to 114 degrees. The water contact angle with a smooth surface made of PFA is said to be 105 to 118 degrees. The water contact angle with the textured surface 72 may be 119 degrees or more, preferably 150 degrees or more. The water contact angle with the mirror surface 71 may be less than 100 degrees.

[0090] Next, contact between the droplet and the uneven surface 72 and the mirror surface 71 will be described.

[0091] Fig. 6 is a schematic cross-sectional view showing an example of a droplet contacting a smooth surface. Fig. 7 is a schematic cross-sectional view showing an example of a droplet contacting a rough surface in a Wenzel state. Fig. 8 is a schematic cross-sectional view showing an example of a droplet contacting a rough surface in a Cassie-Baxter state. Fig. 9 is a schematic cross-sectional view showing an example of the boundary between the liquid contact portion and the liquid.

[0092] As shown in Fig. 8, when a water droplet is placed on the horizontal uneven surface 72 under normal temperature and pressure (room temperature and 1 atmosphere), the tips 72d of the protrusions 72h come into contact with the water droplet while the bottoms 72b of the recesses 72u are separated from the water droplet. In other words, when a water droplet is placed on the horizontal uneven surface 72 under normal temperature and pressure, the uneven surface 72 is in a Cassie-Baxter state. Room temperature is, for example, a constant or approximately constant temperature within a range of 10 to 30°C.

[0093] The Cassie-Baxter model and the Wenzel model are models used to explain wetting of rough surfaces. As shown in Figure 7, in the Wenzel state (hereinafter also referred to as the W state), a water droplet on a horizontal rough surface penetrates into the depressions. In contrast, as shown in Figure 8, in the Cassie-Baxter state (hereinafter also referred to as the CB state), the depressions 72u are filled with air, and the water droplets are supported by the tips 72d of the protrusions 72h.

[0094] Whether a water droplet on a rough surface adopts the W state or the CB state is influenced by factors such as the surface tension of the liquid, the surface free energy of the rough surface (solid), and the surface texture of the rough surface. It is thought that the higher the surface tension of the liquid and the lower the surface free energy of the rough surface (the more water-repellent the rough surface), the more likely the water droplet on the rough surface will adopt the CB state.

[0095] The inner surface 31y of the liquid chemical flow path 31x is made of a water-repellent material such that the contact angle of water with respect to a horizontal, smooth surface exceeds 90 degrees. Therefore, if the surface properties of the uneven surface 72 satisfy certain conditions, a water droplet will contact the horizontal uneven surface 72 in the CB state. In other words, when a water droplet is placed on the horizontal uneven surface 72 under normal temperature and pressure, the tips 72d of the protrusions 72h will contact the water droplet with the bottoms 72b of the recesses 72u separated from the water droplet. If a water droplet contacts the horizontal uneven surface 72 under normal temperature and pressure under the CB state, the liquid chemical in the liquid chemical flow path 31x may contact all or part of the uneven surface 72 in the W state.

[0096] 7 and 8, when a water droplet contacts the horizontal uneven surface 72 in the CB state and when a water droplet contacts the horizontal uneven surface 72 in the W state, the contact area between the water droplet and the uneven surface 72 is smaller when the water droplet contacts the horizontal uneven surface 72 in the CB state. Furthermore, the contact angle of water with the uneven surface 72 is larger when the water droplet contacts the horizontal uneven surface 72 in the CB state.

[0097] The solvent flow path 33x is a flow path that comes into contact with an organic solvent such as IPA. The inner surface 33y of the solvent flow path 33x is made of a water-repellent material that has a contact angle of water exceeding 90 degrees with respect to a horizontal, smooth surface. However, because the surface tension of the organic solvent is low, even if the inner surface 33y of the solvent flow path 33x is rough, the organic solvent in the solvent flow path 33x contacts the inner surface 33y of the solvent flow path 33x in a W-like state. As can be seen from a comparison between FIGS. 6 and 7 , when the inner surface 33y of the solvent flow path 33x is a mirror surface 71 and when it is a rough surface, the contact area between the organic solvent droplets and the inner surface 33y of the solvent flow path 33x is smaller when the inner surface 33y of the solvent flow path 33x is a mirror surface 71.

[0098] Fig. 9 shows an example of an image of the boundary between the liquid contact portion and the liquid. The large circles in Fig. 9 represent fluororesin molecules. The small black circles in Fig. 9 represent impurities. Fig. 9 shows an example in which the impurities are smaller than the fluororesin molecules. The size of the impurities is not limited to this.

[0099] The inner surface 31y of the chemical liquid flow path 31x (see FIG. 8) and the inner surface 33y of the solvent flow path 33x (see FIG. 6) are liquid-contacting parts that come into contact with the liquid. The inner surface of the rinse liquid flow path is also included in the liquid-contacting parts. The liquid-contacting parts are made of resin such as fluororesin. As shown in FIG. 9, fluororesin may contain impurities different from fluororesin (small black circles in FIG. 9). Such impurities may leach from the liquid-contacting parts into the liquid. To prevent this, when the substrate processing apparatus 1 is started up, that is, when the substrate processing apparatus 1 is being prepared for use in a factory such as a semiconductor manufacturing factory, the liquid-contacting parts are cleaned with a cleaning liquid. This cleaning is also called flushing.

[0100] However, even after cleaning, impurities move from the interior of the fluororesin to the surface of the fluororesin. If the substrate processing apparatus 1 is not processing substrates W for a long period of time (a period during which the liquid does not flow along the liquid contacting portion), many impurities accumulate in the liquid contacting portion and dissolve from the liquid contacting portion into the liquid when processing of the substrates W is resumed. Therefore, if the substrate processing apparatus 1 is not processing substrates W for a long period of time, cleaning must be performed before processing of the substrates W is resumed.

[0101] Cleaning not only uses cleaning fluid but also energy such as electricity. If the cleaning time is long, the amount of energy consumed and the amount of cleaning fluid used increases. The same is true if cleaning is done frequently. In order to reduce cleaning costs and the burden on the environment, it is desirable to reduce the time required for cleaning and the number of cleanings.

[0102] On the other hand, even when the substrate processing apparatus 1 continues to process substrates W or when the substrate processing apparatus 1 does not process substrates W for a short period of time, contaminants such as impurities may leach into the liquid from the liquid contact portion. For example, in an area where the liquid has low fluidity (an area where the liquid stagnates or accumulates), many impurities may accumulate in the liquid contact portion and leach into the liquid from the liquid contact portion at an unexpected time. It is also possible that foreign matter contained in the liquid may accumulate in an area where the liquid has low fluidity and flow downstream together with the liquid at an unexpected time.

[0103] The uneven surface 72 of the chemical flow path 31x is the surface where water, such as a chemical solution, contacts the tip 72d of the convex portion 72h while remaining away from the bottom 72b of the recess 72u. Therefore, the contact area between the water and the uneven surface 72 can be reduced compared to when the water contacts the bottom 72b of the recess 72u. Furthermore, because the water does not or is less likely to contact the bottom 72b of the recess 72u, the area where the water contacts the uneven surface 72 can be limited. This narrows the area to be cleaned, thereby shortening the cleaning time. Furthermore, the reduced contact area between the water and the chemical flow path 31x reduces the amount of impurities eluted per unit time from the chemical flow path 31x into the water, thereby reducing the concentration of impurities in the water. Since fewer foreign particles transfer from the water to the uneven surface 72, the concentration of foreign particles in the water can be reduced even if such foreign particles peel off from the uneven surface 72.

[0104] The mirror surface 71 of the solvent flow path 33x has a reduced contact area with the organic solvent. That is, when comparing the case where the inner surface 33y of the solvent flow path 33x has the mirror surface 71 shown in FIG. 6 with the case where the inner surface 33y has the rough surface shown in FIG. 7, the contact area between the organic solvent and the solvent flow path 33x is smaller when the inner surface 33y of the solvent flow path 33x has the mirror surface 71. The reduced contact area between the organic solvent and the solvent flow path 33x reduces the amount of impurities eluted per unit time from the solvent flow path 33x into the organic solvent, thereby reducing the concentration of impurities in the organic solvent. Furthermore, compared to when the inner surface 33y of the solvent flow path 33x has a rough surface, foreign matter contained in the organic solvent is less likely to adhere to the solvent flow path 33x, and the amount of foreign matter transferred from the organic solvent to the solvent flow path 33x is reduced. Therefore, even if foreign matter adhering to the solvent flow path 33x peels off, the concentration of foreign matter in the organic solvent can be reduced.

[0105] Next, the flow of liquid at the bent portion 74 of the chemical liquid flow path 31x will be described.

[0106] Fig. 10 is a schematic diagram showing an example of a cross section of a bent portion 74 of chemical liquid pipe 31p. Fig. 11 is a schematic diagram showing an example of a cross section of bent portion 74 along line XI-XI shown in Fig. 10. Fig. 12 is a schematic diagram showing an example of a cross section of a mold 75 used to manufacture chemical liquid pipe 31p. Fig. 13 is a schematic diagram showing an example of a cross section of mold 75 along line XIII-XIII shown in Fig. 12.

[0107] As shown in Fig. 11 , the inner peripheral surface of the chemical liquid pipe 31p includes a striped surface 73 including a plurality of linear protrusions 73h and a plurality of linear grooves 73u that form a striped pattern extending in the axial direction of the chemical liquid pipe 31p (the direction along the center line 31L of the chemical liquid pipe 31p). The striped surface 73 is one form of the uneven surface 72 (see Fig. 8 ). The linear protrusions 73h are one form of the convex portions 72h (see Fig. 8 ), and the linear grooves 73u are one form of the concave portions 72u (see Fig. 8 ).

[0108] The linear protrusions 73h are spaced apart in the circumferential direction of the chemical liquid pipe 31p (around the center line 31L of the chemical liquid pipe 31p). The same is true for the linear grooves 73u. Each linear groove 73u is formed between two linear protrusions 73h that are closest in the circumferential direction of the chemical liquid pipe 31p. Figure 11 shows an example in which the striped surface 73 is endless and surrounds the center line 31L of the chemical liquid pipe 31p. The striped surface 73 may be formed on only a portion of the inner circumferential surface of the chemical liquid pipe 31p in the circumferential direction of the chemical liquid pipe 31p.

[0109] The linear grooves 73u and the linear protrusions 73h extend in a direction parallel to the center line 31L of the chemical liquid pipe 31p. In the portions where the center line 31L of the chemical liquid pipe 31p is linear, the linear grooves 73u and the linear protrusions 73h are also linear. In the portions where the center line 31L of the chemical liquid pipe 31p is curved, the linear grooves 73u and the linear protrusions 73h are also curved. The width of the linear grooves 73u is shorter than the length of the linear grooves 73u. The width of the linear protrusions 73h is shorter than the length of the linear protrusions 73h. The width of the linear protrusions 73h may be equal to or different from the width of the linear grooves 73u.

[0110] 12 and 13 show an example of a cross section of a mold 75 used to manufacture the chemical liquid pipe 31p by melt extrusion, a type of extrusion molding. The mold 75 is used to mold resin pipes such as the chemical liquid pipe 31p. The mold 75 may be a mold called a die or a mold for molding the molten pipe material, or a mold called a sizing mold for finishing the shape of the pipe that has passed through the die or a mold. The mold 75 includes a core 75c that molds the inner surface of the pipe and a ring 75r that molds the outer surface of the pipe. FIG. 13 shows the appearance of the core 75c.

[0111] The material for the resin pipe, such as the chemical liquid pipe 31p, is supplied to a cylindrical space 75s between the core 75c and the ring 75r and is continuously extruded from the space 75s. This forms the pipe. At this time, irregularities identical to or nearly identical to the irregularities on the outer surface of the core 75c are formed on the inner surface of the pipe. This forms the striped surface 73. The pipe extruded from the mold 75 is straight. If a bent portion 74 is to be formed in the pipe, the straight pipe may be temporarily softened by heating and then bent. If the pipe is flexible, the pipe may be bent without heating.

[0112] 10 shows an example in which the bent portion 74 includes a linear upstream portion 74u, a linear downstream portion 74d inclined at a certain angle relative to the upstream portion 74u, and an arc-shaped corner portion 74c extending from the upstream portion 74u to the downstream portion 74d. In this example, the bent portion 74 is bent 90 degrees. In other words, the upstream portion 74u and the downstream portion 74d are arranged on two perpendicular lines. The upstream portion 74u, the corner portion 74c, and the downstream portion 74d are all cylindrical. The linear grooves 73u and linear protrusions 73h of the striped surface 73 are bent at the bent portion 74.

[0113] The spiral curves in Figure 10 represent areas where stagnation or retention of liquid occurs. The striped surface 73 provided on the inner circumferential surface of the bent portion 74 reduces the contact area between the water and the bent portion 74, thereby limiting the area where the water comes into contact with the bent portion 74. Furthermore, the resistance applied to the water from the inner circumferential surface of the bent portion 74 is reduced, thereby minimizing the decrease in water velocity at the bent portion 74 and minimizing the area where stagnation or retention occurs. This reduces impurities and foreign matter that accumulate in such areas, and reduces the amount of contaminants that migrate from the inner circumferential surface of the bent portion 74 to the water flowing through the bent portion 74.

[0114] Next, the effects of this embodiment will be described.

[0115] In this embodiment, water is guided toward the substrate W through the water flow path, and an organic solvent, which is a liquid with a lower surface tension than water, is guided toward the substrate W through the solvent flow path 33x. The chemical liquid flow path 31x and the rinse liquid flow path are examples of water flow paths, and the chemical liquid and the rinse liquid are examples of water. The water flow path includes an uneven surface 72 that comes into contact with water. The solvent flow path 33x includes a mirror surface 71 that comes into contact with the organic solvent.

[0116] The uneven surface 72 of the chemical solution flow path 31x includes a recess 72u at least partially filled with air and a protrusion 72h that contacts the water that contacts the air in the recess 72u. Because the recess 72u is at least partially filled with air, the contact area between the water and the uneven surface 72 is reduced compared to when the entire recess 72u is filled with water. Furthermore, because the water does not or is unlikely to come into contact with the inner surface of the recess 72u, the area in contact with the uneven surface 72 can be limited. This narrows the area to be cleaned with the cleaning liquid, thereby shortening the cleaning time.

[0117] The mirror surface 71 of the solvent flow path 33x is a smooth surface that comes into contact with the organic solvent. Because the surface tension of the organic solvent is low, even if the inner surface 33y of the solvent flow path 33x is rough, the organic solvent in the solvent flow path 33x enters the grooves of the roughened surface. In this case, if the surface roughness of the roughened surface is reduced, the contact area between the organic solvent and the solvent flow path 33x also decreases. If the surface roughness is made extremely small, the roughened surface becomes the mirror surface 71. Therefore, by providing the mirror surface 71 on the inner surface 33y of the solvent flow path 33x, the area to be cleaned with the cleaning liquid can be narrowed compared to when the inner surface 33y of the solvent flow path 33x is rough, and the cleaning time can be shortened.

[0118] In this embodiment, all or part of the textured surface 72 is made of fluororesin. Fluororesin is a highly water-repellent material. Whether a liquid droplet on a rough surface adopts the Wenzel state or the Cassie-Baxter state depends on factors such as the surface tension of the liquid, the surface free energy of the rough surface (solid), and the surface properties of the rough surface. By making the textured surface 72 out of a highly water-repellent material, it is possible to maintain a state in which at least a portion of the recesses 72u is filled with air. This allows the contact area between water and the textured surface 72 to be limited while reducing the contact area between the water and the textured surface 72.

[0119] In this embodiment, the chemical liquid is guided from the chemical liquid tank 31t to the chemical liquid pipe 31p. The chemical liquid tank 31t and the chemical liquid pipe 31p correspond to a water tank and a water pipe. The uneven surface 72 is provided on the inner surface of the chemical liquid tank 31t. The time that the chemical liquid is in contact with the chemical liquid tank 31t is longer than the time that the chemical liquid is in contact with the chemical liquid pipe 31p. Therefore, by reducing the contact area between the chemical liquid and the chemical liquid tank 31t, it is possible to effectively reduce contaminants transferred from the chemical liquid tank 31t to the chemical liquid.

[0120] In this embodiment, the organic solvent is guided from the solvent tank 33t to the solvent pipe 33p. The mirror surface 71 is provided on the inner surface of the solvent tank 33t. The time that the organic solvent is in contact with the solvent tank 33t is longer than the time that the organic solvent is in contact with the solvent pipe 33p. Therefore, by reducing the contact area between the organic solvent and the solvent tank 33t, it is possible to effectively reduce the amount of contaminants transferred from the solvent tank 33t to the organic solvent.

[0121] In this embodiment, an uneven surface 72 is provided on the inner surface of a bent portion 74 of a chemical liquid flow path 31x, which is an example of a water flow path. Areas of low liquid fluidity (areas where liquid stagnation or retention occurs) may occur in the bent portion 74. In such cases, contaminants such as particles may accumulate in the bent portion 74 and flow along with the chemical liquid at unexpected times. Providing the uneven surface 72 on the inner surface of the bent portion 74 reduces the resistance applied to the chemical liquid from the inner surface of the bent portion 74, thereby minimizing the decrease in the speed of the chemical liquid at the bent portion 74 and minimizing the areas where stagnation or retention occurs. This reduces impurities and foreign matter that accumulate in such areas and reduces the amount of contaminants that migrate from the inner surface of the bent portion 74 to the chemical liquid flowing through the bent portion 74.

[0122] Next, another embodiment will be described.

[0123] Instead of providing the uneven surface 72 or the striped surface 73 on the liquid chemical tank 31t and the bent portion 74, the uneven surface 72 or the striped surface 73 may be provided only on the liquid chemical tank 31t or only on the bent portion 74.

[0124] The striped surface 73 may be provided on a part of the inner surface 31y of the chemical flow path 31x other than the inner circumferential surface of the chemical pipe 31p, such as the inner surface of the chemical tank 31t. In this case, the direction of the linear protrusions 73h and the linear grooves 73u does not have to be parallel to the flow direction of the chemical solution.

[0125] The substrate processing apparatus 1 is not limited to an apparatus for processing a disk-shaped substrate W, but may also be an apparatus for processing a polygonal substrate W. The substrate processing apparatus 1 may also be a batch-type apparatus for processing a plurality of substrates W at once.

[0126] 14 , the batch-type substrate processing apparatus 1 includes a lifter 81 that moves up and down between an upper position and a lower position while holding a plurality of substrates W, and an inner bath 82 that stores a processing liquid in which the plurality of substrates W held by the lifter 81 in the lower position are immersed. The batch-type substrate processing apparatus 1 further includes a nozzle 87 that supplies the processing liquid into the inner bath 82, an outer bath 83 that stores the processing liquid that overflows from the inner bath 82, a circulation pipe 84 that guides the processing liquid from the outer bath 83 to the nozzle 87, a pump 85 that sends the processing liquid from the outer bath 83 to the nozzle 87 through the circulation pipe 84, and a filter 86 that removes foreign matter from the processing liquid flowing through the circulation pipe 84. The lifter 81 corresponds to a substrate holder.

[0127] The processing liquid supplied to the inner tank 82 may be water, such as a chemical liquid or a rinse liquid, or an organic solvent. The outer tank 83 corresponds to the start position of the water flow path or the solvent flow path 33x. The inner tank 82 corresponds to the goal position of the water flow path or the solvent flow path 33x. When the processing liquid is water, an uneven surface 72 is provided on the inner surface of at least one of the inner tank 82, the outer tank 83, the circulation pipe 84, the pump 85, the filter 86, and the nozzle 87. When the processing liquid is an organic solvent, a mirror surface 71 is provided on the inner surface of at least one of the inner tank 82, the outer tank 83, the circulation pipe 84, the pump 85, the filter 86, and the nozzle 87.

[0128] Figure 15 is a schematic diagram showing another example of the configuration of the processing unit 2, and shows the configuration of the interior of the processing unit 2 viewed horizontally, similar to Figure 2. In Figure 15, parts corresponding to those in Figure 2 are given the same reference numerals, and the configuration and operation are substantially the same as those in Figure 2, so their explanation will be omitted.

[0129] This configuration example differs from the configuration example shown in FIG. 2 in the processing liquid supply system and the substrate processing, and therefore these will be mainly described.

[0130] Processing unit 2 includes a plurality of nozzles that discharge processing fluids toward substrate W held on spin chuck 10. The plurality of nozzles includes a first chemical liquid nozzle 131 that discharges a first chemical liquid toward the upper surface of substrate W, a second chemical liquid nozzle 132 that discharges a second chemical liquid toward the upper surface of substrate W, and a rinse liquid nozzle 134 (first rinse liquid nozzle) that discharges a rinse liquid toward the upper surface of substrate W. The plurality of nozzles also includes a third chemical liquid nozzle 133 that discharges a third chemical liquid toward the upper surface of substrate W. FIG. 15 shows a case where the first chemical liquid is DHF (dilute hydrofluoric acid), which is an example of an acid; the second chemical liquid is a sulfuric acid-hydrogen peroxide mixture (so-called SPM (sulfuric acid-hydrogen peroxide mixture)) that has an effect of removing organic matter such as resist; and the third chemical liquid is an ammonia-hydrogen peroxide mixture (so-called SC1: Standard Clean 1), which is an example of an alkali. FIG. 15 also shows a case where the rinse liquid discharged from the rinse liquid nozzle 134 is DIW (deionized water). As described above, the rinse liquid may be other than DIW.

[0131] 2 , the plurality of nozzles further include a rinse liquid nozzle 32 (second rinse liquid nozzle) that discharges a rinse liquid toward the upper surface of the substrate W, and a solvent nozzle 33 that discharges an organic solvent toward the upper surface of the substrate W. Similar to the configuration example of FIG. 2 , FIG. 15 shows an example in which the rinse liquid nozzle 32 discharges DIW and the solvent nozzle 33 discharges IPA (isopropyl alcohol). The type of rinse liquid discharged from the rinse liquid nozzle 32 and the type of organic solvent discharged from the solvent nozzle 33 are as described above. Furthermore, the configuration of the rinse liquid supply system to the rinse liquid nozzle 32 and the configuration of the organic solvent supply system to the solvent nozzle 33 are also as described above and are the same as those in the configuration example of FIG. 2 .

[0132] 15 , a shielding plate may be provided facing from above the upper surface of the substrate W held by the spin chuck 10. In this case, the rinse liquid nozzle 32 and the solvent nozzle 33 may be attached to the shielding plate and arranged to eject liquid from the center of the shielding plate toward the center of the substrate W.

[0133] First chemical liquid nozzle 131, second chemical liquid nozzle 132, and rinse liquid nozzle 134 are connected to nozzle movement unit 38. Nozzle movement unit 38 changes the landing positions (i.e., the distances of the landing positions from rotation axis A1) of the liquids discharged from first chemical liquid nozzle 131, second chemical liquid nozzle 132, and rinse liquid nozzle 134 in the radial direction (radial direction from rotation axis A1) on substrate W. As a result, first chemical liquid nozzle 131, second chemical liquid nozzle 132, and rinse liquid nozzle 134 have the form of a scan nozzle whose landing positions change in the radial direction on substrate W. For example, nozzle movement unit 38 may be a turning unit that turns first chemical liquid nozzle 131, second chemical liquid nozzle 132, and rinse liquid nozzle 134 along a horizontal, arc-shaped path that passes near rotation axis A1. Third chemical liquid nozzle 133 is connected to nozzle movement unit 133m. Nozzle moving unit 133m changes the radial landing position on substrate W of the liquid discharged from third chemical liquid nozzle 133. As a result, third chemical liquid nozzle 133 has the form of a scan nozzle in which the landing position changes radially on substrate W. For example, nozzle moving unit 133m may be a turning unit that turns third chemical liquid nozzle 133 along a horizontal arc-shaped path that passes near rotation axis A. One or more of first chemical liquid nozzle 131, second chemical liquid nozzle 132, third chemical liquid nozzle 133, and rinse liquid nozzle 134 may be fixed nozzles fixed within processing unit 2.

[0134] First chemical liquid nozzle 131 is connected to first chemical liquid pipe 131p, which guides DHF toward first chemical liquid nozzle 131. Rinse liquid nozzle 134 is connected to rinse liquid pipe 134p, which guides deionized water toward rinse liquid nozzle 134. When first chemical liquid valve 131v, which is provided in first chemical liquid pipe 131p, is opened, DHF is supplied from first chemical liquid pipe 131p to first chemical liquid nozzle 131 and is continuously discharged downward from first chemical liquid nozzle 131. When rinse liquid valve 134v, which is provided in rinse liquid pipe 134p, is opened, deionized water is supplied from rinse liquid pipe 134p to rinse liquid nozzle 134 and is continuously discharged downward from rinse liquid nozzle 134. The temperature of the deionized water discharged from rinse liquid nozzle 134 may be room temperature or higher.

[0135] Second chemical solution nozzle 132 is connected to sulfuric acid piping 132p, which guides sulfuric acid toward second chemical solution nozzle 132, and hydrogen peroxide solution piping 135p, which guides hydrogen peroxide solution toward second chemical solution nozzle 132. Sulfuric acid valve 132v and flow rate adjustment valve 132f are provided in sulfuric acid piping 132p. Hydrogen peroxide solution valve 135v and flow rate adjustment valve 135f are provided in hydrogen peroxide solution piping 135p.

[0136] When sulfuric acid valve 132v is opened, sulfuric acid is supplied from sulfuric acid pipe 132p to second chemical nozzle 132 at a flow rate corresponding to the opening of flow rate adjustment valve 132f. When hydrogen peroxide solution valve 135v is opened, hydrogen peroxide solution is supplied from hydrogen peroxide solution pipe 135p to second chemical nozzle 132 at a flow rate corresponding to the opening of flow rate adjustment valve 135f. When sulfuric acid valve 132v and hydrogen peroxide solution valve 135v are opened, sulfuric acid and hydrogen peroxide solution mix to generate SPM. This SPM is then continuously discharged downward from second chemical solution nozzle 132 toward the upper surface of substrate W.

[0137] The flow rate of the SPM discharged from second chemical nozzle 132 and the mixture ratio of sulfuric acid and hydrogen peroxide solution (the ratio of the flow rate of sulfuric acid to the flow rate of hydrogen peroxide solution) are changed by flow rate adjustment valve 132 f and flow rate adjustment valve 135 f. The temperature of the SPM discharged from second chemical nozzle 132 is changed depending on the mixture ratio of sulfuric acid and hydrogen peroxide solution, the temperature of sulfuric acid before mixing, and the temperature of hydrogen peroxide solution before mixing.

[0138] The mixing ratio of sulfuric acid and hydrogen peroxide solution (the ratio of the flow rate of sulfuric acid to the flow rate of hydrogen peroxide solution) is, for example, 2 or more. When sulfuric acid and hydrogen peroxide solution are mixed, high-temperature SPM is generated due to the heat of dilution of the sulfuric acid. The temperature of the SPM discharged from second chemical solution nozzle 132 is, for example, higher than 100°C. The temperature of sulfuric acid before being mixed with hydrogen peroxide solution is higher than room temperature, for example, higher than 100°C. Substrate processing apparatus 1 is equipped with heater 34h that heats the sulfuric acid supplied to second chemical solution nozzle 132. The temperature of hydrogen peroxide solution before being mixed with sulfuric acid is, for example, room temperature (e.g., 20 to 30°C). The temperature of hydrogen peroxide solution before being mixed with sulfuric acid may be higher than room temperature.

[0139] Third chemical solution nozzle 133 is connected to third chemical solution pipe 133p, which guides SC1 toward third chemical solution nozzle 133. When third chemical solution valve 133v provided in third chemical solution pipe 133p is opened, SC1 is supplied from third chemical solution pipe 133p to third chemical solution nozzle 133 and is continuously discharged downward from third chemical solution nozzle 133.

[0140] Next, an example of processing of the substrate W will be described.

[0141] Fig. 16 is a process diagram for explaining an example of processing of a substrate W performed by the substrate processing apparatus 1. Fig. 16 shows an example in which these processing liquids are supplied to the substrate W in the following order: DHF, pure water, SPM, pure water, SC1, and IPA.

[0142] The substrate W to be processed is, for example, a semiconductor wafer such as a silicon wafer. The surface of the substrate W corresponds to a device formation surface on which devices such as transistors and capacitors are formed. An example of resist removal will be described below, in which an SPM, which is an example of a resist removal liquid and a resist stripping liquid, is supplied to the upper surface of the substrate W to remove an unnecessary resist mask from the substrate W. The processing of the substrate W may be other than resist removal.

[0143] When a substrate W is to be processed, the indexer robot IR takes the substrate W out of the carrier CA on one of the load ports LP. The center robot CR carries the substrate W taken out by the indexer robot IR into one of the processing units 2 and places it on the spin chuck 10. Thereafter, a plurality of chuck pins 11 are pressed horizontally against the edge surface of the substrate W, and the spin motor 14 starts to rotate. This starts the rotation of the substrate W.

[0144] When the rotation of the substrate W begins, the first chemical liquid valve 131v is opened, and the first chemical liquid nozzle 131 discharges DHF toward the upper surface of the rotating substrate W. This causes the entire upper surface of the substrate W to be treated with DHF (step S11: an example of a water supply process). This treatment may be a pre-cleaning process in which the surface of the substrate W is lightly etched (e.g., a native oxide film is etched) to remove foreign matter. While the first chemical liquid nozzle 131 is discharging DHF, the nozzle movement unit 38 may move the first chemical liquid nozzle 131 so that the collision position of the DHF with the upper surface of the substrate W passes through the center and the outer periphery, or may keep the first chemical liquid nozzle 131 stationary so that the collision position remains stationary at the center. Whether or not the collision position is moved is the same for other processing liquids (pure water, SPM, SC1, IPA).

[0145] When a predetermined time has elapsed since the first chemical liquid valve 131v was opened, the first chemical liquid valve 131v is closed, and the rinse liquid valve 134v is opened. In response to this, the rinse liquid nozzle 134 ejects pure water, an example of a rinse liquid, toward the upper surface of the rotating substrate W. As a result, the DHF on the substrate W is replaced with pure water, and the DHF is removed from the entire upper surface of the substrate W (step S12: an example of a water supplying step). Before the rinse process with pure water, a solvent rinse step (an example of a solvent supplying step) may be performed in which IPA is supplied to the substrate W from the solvent nozzle 33.

[0146] After the deionized water rinse process for a predetermined time, the rinse liquid valve 134v is closed. Then, the SPM process is started (step S13: an example of a high-temperature chemical liquid supply process). That is, the sulfuric acid valve 132v and the hydrogen peroxide solution valve 135v are opened, whereby the sulfuric acid and the hydrogen peroxide solution are mixed in the second chemical liquid nozzle 132 to generate SPM, which is then discharged from the second chemical liquid nozzle 132 toward the substrate W. As a result, the entire upper surface of the substrate W is treated with the SPM. This SPM process strips the resist from the upper surface of the substrate W and removes it from the substrate W.

[0147] After a predetermined time, the sulfuric acid valve 132v and the hydrogen peroxide solution valve 135v are closed, and the SPM process is completed. Next, the rinse liquid valve 134v is opened. In response, the rinse liquid nozzle 134 ejects pure water, an example of a rinse liquid, toward the upper surface of the rotating substrate W. As a result, the SPM on the substrate W is replaced with pure water, and the SPM is removed from the entire upper surface of the substrate W (step S14: an example of a water supply step).

[0148] After the deionized water rinse process for a predetermined time, the rinse liquid valve 134v is closed. Then, chemical liquid process using SC1 is started (step S15). That is, the third chemical liquid valve 133v is opened, and the third chemical liquid nozzle 133 discharges SC1 toward the upper surface of the rotating substrate W. As a result, the entire upper surface of the substrate W is treated with SC1. This process may be a residue removal process that removes residues remaining on the substrate after the SPM process and the rinse process.

[0149] After a predetermined time, the third chemical liquid valve 133v is closed, and the chemical liquid processing using SC1 is terminated. Next, the solvent valve 33v is opened. In response, the solvent nozzle 33 ejects IPA, an example of an organic solvent, toward the upper surface of the rotating substrate W. As a result, SC1 on the substrate W is replaced with IPA, and a liquid film of IPA is formed covering the entire upper surface of the substrate W (step S16: an example of a solvent supplying step). Thereafter, the solvent valve 33v is closed. Note that after the chemical liquid processing using SC1, a pure water rinse process may be performed before the supply of IPA begins.

[0150] When the solvent valve 33v is closed, the spin motor 14 rotates the substrate W held by the multiple chuck pins 11 at a high rotational speed (e.g., several thousand rpm). This removes the liquid from the substrate W, and the substrate W dries (step S17). After the substrate W has dried, the spin motor 14 stops, and the multiple chuck pins 11 move away from the edge of the substrate W. This stops the rotation of the substrate W, and the substrate W is released from its hold. Thereafter, the center robot CR unloads the substrate W from the processing unit 2. The indexer robot IR loads the substrate W unloaded by the center robot CR into a carrier CA on one of the load ports LP.

[0151] In this way, one substrate W is treated with a treatment liquid such as a chemical liquid or a rinse liquid. The control device 3 controls the indexer robot IR and the like to cause the substrate treatment apparatus 1 to repeat the above-described series of operations. In this way, a plurality of substrates W are treated one by one.

[0152] Next, the processing liquid supply system will be described.

[0153] The first chemical liquid, DHF (dilute hydrofluoric acid), has a volumetric composition ratio of HF / H2O of approximately 1 / 1000 to 1 / 100, and its surface tension is equal to or nearly equal to that of water (H2O), making it a liquid that can be treated as an example of water. Therefore, the path through which DHF passes before reaching the outlet 131d of the first chemical liquid nozzle 131 is a single chemical liquid flow path 131x that is continuous from the start position to the goal position, and is an example of a water flow path. The structure of the chemical liquid flow path 131x through which DHF passes is substantially similar to the structure of the chemical liquid flow path 31x described with reference to FIG. 5A and other figures. Therefore, the above description of the structure of the chemical liquid flow path 31x will be quoted, with "chemical liquid" replaced with "DHF," and will be substituted for the description of the flow path structure of the chemical liquid flow path 131x through which DHF passes.

[0154] Furthermore, the third chemical liquid, SC1 (ammonia-hydrogen peroxide solution mixture), has a composition ratio, for example, of 1:1 by volume of ammonia water (28-30 wt %), 1:1 by volume of hydrogen peroxide solution (30 wt %), and 5:5 by volume of water. Its surface tension is equal to or approximately equal to that of water (HO), and it can be treated as an example of water. Therefore, the path through which SC1 passes before reaching the outlet 133d of the third chemical liquid nozzle 133 is a single chemical liquid flow path 133x that is continuous from the start position to the goal position, and is an example of a water flow path. The structure of the chemical liquid flow path 133x through which SC1 passes is substantially similar to the structure of the chemical liquid flow path 31x described with reference to FIG. 5A and other figures. Therefore, the above description of the structure of the chemical liquid flow path 31x will be quoted here, with "chemical liquid" replaced with "SC1," and will be substituted for the description of the flow path structure of the chemical liquid flow path 133x through which SC1 passes.

[0155] Next, the path through which the rinse liquid passes before being discharged from the discharge port 134d of the rinse liquid nozzle 134 corresponds to one rinse liquid flow path 134x that continues from the start position to the goal position. The structure of this rinse liquid flow path 134x is similar to that of the rinse liquid flow path described with respect to the rinse liquid nozzle 32 in the configuration example of the processing unit 2 in FIG. 2 , and therefore a description thereof will be omitted.

[0156] The structure of the rinse liquid flow path 32x, which is a path through which the rinse liquid passes before being discharged from the discharge port 32d of the rinse liquid nozzle 32, is the same as that in the configuration example of the processing unit 2 in Fig. 2. In addition, the structure of the solvent flow path 33x, which is a path through which the organic solvent passes before being discharged from the discharge port 33d of the solvent nozzle 33, is also the same as that in the configuration example of the processing unit 2 in Fig. 2.

[0157] 17 is a schematic diagram of a chemical liquid supply system that supplies SPM as a second chemical liquid to substrates W. The substrate processing apparatus 1 includes a sulfuric acid tank 132t that stores sulfuric acid (typically concentrated sulfuric acid) and a hydrogen peroxide tank 135t that stores hydrogen peroxide. The sulfuric acid stored in the sulfuric acid tank 132t is, more precisely, a sulfuric acid-containing liquid. For example, SPM used to process substrates W may be recovered, subjected to a necessary regeneration process, and then introduced into the sulfuric acid tank 132t to be used as sulfuric acid (sulfuric acid-containing liquid). The upstream end of a sulfuric acid pipe 132p is connected to the sulfuric acid tank 132t, and the upstream end of a hydrogen peroxide pipe 135p is connected to the hydrogen peroxide tank 135t. The downstream ends of the sulfuric acid pipe 132p and the hydrogen peroxide pipe 135p are connected to the second chemical liquid nozzle 132. Sulfuric acid piping 132p is equipped with a sulfuric acid pump 132P that sends sulfuric acid in sulfuric acid tank 132t toward second chemical nozzle 132, and a sulfuric acid filter 132F that removes foreign matter from the sulfuric acid sent out from sulfuric acid tank 132t. Hydrogen peroxide piping 135p is equipped with a pump 135P that sends hydrogen peroxide in hydrogen peroxide tank 135t toward second chemical nozzle 132, and a filter 135F that removes foreign matter from the hydrogen peroxide sent out from hydrogen peroxide tank 135t.

[0158] The hydrogen peroxide solution supplied to second chemical solution nozzle 132 and mixed with sulfuric acid is a liquid with a surface tension similar to that of water (HO), and may be treated as an example of water when designing the flow path structure. Therefore, the path through which the hydrogen peroxide solution passes before reaching second chemical solution nozzle 132 is a single, continuous chemical solution flow path 135x extending from the start position to the goal position, and is an example of a water flow path. The structure of chemical solution flow path 135x through which the hydrogen peroxide solution passes is substantially similar to the structure of chemical solution flow path 31x described with reference to FIG. 5A and other figures. Therefore, the above description of the structure of chemical solution flow path 31x will be quoted here, with "chemical solution" replaced with "hydrogen peroxide solution," and will be substituted for the description of the flow path structure of chemical solution flow path 135x for hydrogen peroxide solution.

[0159] Meanwhile, sulfuric acid (concentrated sulfuric acid) supplied to the second chemical nozzle 132 and mixed with hydrogen peroxide, and SPM obtained by mixing sulfuric acid and hydrogen peroxide, are examples of high-temperature chemicals that are hotter than room temperature. While the behavior of sulfuric acid (especially concentrated sulfuric acid) and SPM as liquids is difficult to equate with that of water, the high-temperature chemical flow path that contacts the sulfuric acid and SPM, particularly if it is made of a resin material such as a fluororesin, may cause impurities (especially plasticizers) in the resin material to dissolve into the chemical. Therefore, similar to the water flow path described above, it is preferable to design the high-temperature chemical flow path to minimize the contact area with the chemical.

[0160] The path that the high-temperature chemical (sulfuric acid or SPM) takes before being discharged from outlet 132d of second chemical nozzle 132 corresponds to a single continuous high-temperature chemical flow path 132x that extends from the start position to the goal position. Sulfuric acid tank 132t is an example of a high-temperature chemical tank, and corresponds to the start position of high-temperature chemical flow path 132x. Second chemical nozzle 132 is an example of a high-temperature chemical nozzle, and its outlet 132d corresponds to the goal position of high-temperature chemical flow path 132x.

[0161] The high-temperature chemical flow path 132x includes a second chemical nozzle 132 having an outlet 132d for discharging SPM, and a sulfuric acid pipe 132p for guiding sulfuric acid toward the second chemical nozzle 132. The sulfuric acid pipe 132p is an example of a high-temperature chemical pipe. The high-temperature chemical flow path 132x may further include fluid devices other than the second chemical nozzle 132 and the sulfuric acid pipe 132p. In this example, the high-temperature chemical flow path 132x includes a sulfuric acid valve 132v, a flow rate adjustment valve 132f, a sulfuric acid tank 132t, a sulfuric acid pump 132P, a sulfuric acid filter 132F, and a heater 132h. Instead of or in addition to at least one of these, the high-temperature chemical flow path 132x may further include at least one of a circulation pipe for circulating sulfuric acid from downstream of the heater 132h to the sulfuric acid tank 132t, a flow meter for measuring the flow rate of sulfuric acid supplied to the second chemical nozzle 132, a fitting for connecting two or more pipes, and a manifold for connecting three or more pipes.

[0162] The high-temperature chemical flow path 132x includes an internal space in which a flowing or stationary high-temperature chemical (sulfuric acid or SPM) is placed, and a cylindrical inner surface 132y that surrounds the entire internal space. The internal space of the high-temperature chemical flow path 132x is an enclosed space that is open only at the goal position of the high-temperature chemical flow path 132x. In other words, the internal space of the high-temperature chemical flow path 132x is in contact with the space outside the high-temperature chemical flow path 132x only at the goal position of the high-temperature chemical flow path 132x.

[0163] The inner surface 132y of the high-temperature chemical liquid flow path 132x is made of a resin such as a fluororesin. The fluororesin may be PTFE (Polytetrafluoroethylene) or PFA (Perfluoroalkoxyalkane), or may be other materials. The entire inner surface 132y of the high-temperature chemical liquid flow path 132x may be made of the same material, or a portion of the inner surface 132y of the high-temperature chemical liquid flow path 132x may be made of a different material from the remaining portion of the inner surface 132y of the high-temperature chemical liquid flow path 132x.

[0164] 17, the inner surface 132y of the high-temperature chemical liquid flow path 132x includes an uneven surface 172 that comes into contact with the chemical liquid (sulfuric acid or SPM) in the high-temperature chemical liquid flow path 132x. The uneven surface 172 is a rough surface that has a surface roughness greater than that of the mirror surface 71 (see FIG. 5B).

[0165] The entire inner surface 132y of the high-temperature chemical liquid flow path 132x may be the uneven surface 172, or only a portion of the inner surface 132y of the high-temperature chemical liquid flow path 132x may be the uneven surface 172. Figure 17 shows an example in which all or a portion of the inner surfaces of the sulfuric acid tank 132t and the second chemical liquid nozzle 132 are the uneven surface 172.

[0166] The uneven surface 172 is a water-repellent surface that has been subjected to a water-repellent treatment similar to that of the chemical solution flow path 31x described above, which results in a large contact angle of sulfuric acid and a correspondingly small contact area with sulfuric acid. The water-repellent treatment may be at least one of cutting, laser processing, plastic processing, extrusion molding, blasting, and etching, or may be other than these.

[0167] As shown in Figure 17, the uneven surface 172 is a solid surface provided with a plurality of recesses 172u and a plurality of protrusions 172h. The recesses 172u are recessed from the tips 172d of the protrusions 172h. The protrusions 172h protrude from the bottoms 172b of the recesses 172u. The bottoms 172b of the recesses 172u correspond to the bases of the protrusions 172h. The tips 172d of the protrusions 172h correspond to the opening ends of the recesses 172u. The tips 172d of two adjacent protrusions 172h form the entrance of the recess 172u located between them.

[0168] The convex portion 172h may be linear with a depth greater than its width, or may be dot-shaped with a depth equal to or approximately equal to its width, or may have other shapes. The same applies to the concave portion 172u. The cross section of the convex portion 172h may be rectangular, square, triangular, inverted triangle, trapezoid, inverted trapezoid, or semicircular, or may have other shapes. The same applies to the cross section of the concave portion 172u. Figure 17 shows an example in which the cross sections of the convex portion 172h and the concave portion 172u are rectangular. The height of the convex portion 172h (the length in the horizontal direction in Figure 17) may be uniform or non-uniform. The same applies to the depth of the concave portion 172u. The height of the convex portion 172h may be equal to or different from the width of the convex portion 172h (the length in the vertical direction in Figure 17). The depth of the concave portion 172u may be equal to or different from the width of the concave portion 172u.

[0169] The contact angle of water with the uneven surface 172 may be 119 degrees or more, preferably 150 degrees or more.

[0170] The inner surface 132y of the high-temperature chemical liquid flow path 132x is a liquid-contacting portion that comes into contact with the liquid. The liquid-contacting portion is made of a resin such as a fluororesin. As described with reference to FIG. 9 , the fluororesin may contain impurities (small black circles in FIG. 9 ) that are different from the fluororesin. An example of an impurity is a plasticizer. Such impurities may leach from the liquid-contacting portion into the high-temperature chemical liquid. To prevent this, when the substrate processing apparatus 1 is started up, that is, when the substrate processing apparatus 1 is being prepared for use in a factory such as a semiconductor manufacturing factory, the liquid-contacting portion is cleaned with a cleaning liquid. This cleaning is also called flushing.

[0171] However, even after cleaning, impurities such as plasticizers migrate from the interior of the fluororesin to the surface of the fluororesin. If the substrate processing apparatus 1 is not processing substrates W for a long period of time (a period during which the liquid does not flow along the liquid contacting portion), many impurities accumulate in the liquid contacting portion and dissolve from the liquid contacting portion into the liquid when processing of the substrates W is resumed. Therefore, if the substrate processing apparatus 1 is not processing substrates W for a long period of time, cleaning must be performed before processing of the substrates W is resumed.

[0172] Cleaning not only uses cleaning fluid but also energy such as electricity. If the cleaning time is long, the amount of energy consumed and the amount of cleaning fluid used increases. The same is true if cleaning is done frequently. In order to reduce cleaning costs and the burden on the environment, it is desirable to reduce the time required for cleaning and the number of cleanings.

[0173] On the other hand, even when the substrate processing apparatus 1 continues to process substrates W or when the substrate processing apparatus 1 does not process substrates W for a short period of time, contaminants such as impurities may leach into the liquid from the liquid contact portion. For example, in an area where the liquid has low fluidity (an area where the liquid stagnates or accumulates), many impurities may accumulate in the liquid contact portion and leach into the liquid from the liquid contact portion at an unexpected time. It is also possible that foreign matter contained in the liquid may accumulate in an area where the liquid has low fluidity and flow downstream together with the liquid at an unexpected time.

[0174] The uneven surface 172 of the high-temperature chemical flow path 132x is the surface where the high-temperature chemical liquid comes into contact with the tip 172d of the convex portion 172h when the high-temperature chemical liquid is away from the bottom 172b of the concave portion 172u. Therefore, the contact area between the high-temperature chemical liquid and the uneven surface 172 can be reduced compared to when the high-temperature chemical liquid comes into contact with the bottom 172b of the concave portion 172u. Furthermore, because the high-temperature chemical liquid does not or is unlikely to come into contact with the bottom 172b of the concave portion 172u, the area where the high-temperature chemical liquid comes into contact with the uneven surface 172 can be limited. This narrows the area to be cleaned, thereby shortening the cleaning time. Furthermore, the reduced contact area between the high-temperature chemical liquid and the high-temperature chemical flow path 132x reduces the amount of impurities eluted per unit time from the high-temperature chemical flow path 132x into the high-temperature chemical liquid, thereby reducing the impurity concentration in the high-temperature chemical liquid. The amount of foreign matter transferred from the high-temperature chemical liquid to the uneven surface 172 is also reduced, so even if such foreign matter peels off from the uneven surface 172, the concentration of foreign matter in the high-temperature chemical liquid can be reduced.

[0175] FIG. 18 is a cross-sectional view showing an example of the cross-sectional structure of a sulfuric acid pipe 132p, which is an example of a high-temperature chemical liquid pipe. The inner surface of the sulfuric acid pipe 132p includes a striped surface 173 including a plurality of linear protrusions 173h and a plurality of linear grooves 173u that form a striped pattern extending in the axial direction of the sulfuric acid pipe 132p (a direction along the center line 132L of the sulfuric acid pipe 132p). The striped surface 173 is one form of the uneven surface 172 (see FIG. 17). The linear protrusions 173h are one form of the convex portions 172h (see FIG. 17), and the linear grooves 173u are one form of the concave portions 172u (see FIG. 17). Preferably, the inner surface of the sulfuric acid pipe 132p, preferably the entire section, or at least a portion of the section including the bend, is formed into such a striped surface 173.

[0176] The multiple linear protrusions 173h are arranged at intervals in the circumferential direction of the sulfuric acid pipe 132p (the direction around the center line 132L of the sulfuric acid pipe 132p). The same is true for the multiple linear grooves 173u. Each of the multiple linear grooves 173u is formed between the two linear protrusions 173h that are closest in the circumferential direction of the sulfuric acid pipe 132p. Figure 18 shows an example in which the striped surface 173 is endless and surrounds the center line 132L of the sulfuric acid pipe 132p. The striped surface 173 may be formed only in a portion of the inner circumferential surface of the sulfuric acid pipe 132p in the circumferential direction of the sulfuric acid pipe 132p.

[0177] The linear grooves 173u and the linear protrusions 173h extend in a direction parallel to the center line 132L of the sulfuric acid pipe 132p. In portions where the center line 132L of the sulfuric acid pipe 132p is linear, the linear grooves 173u and the linear protrusions 173h are also linear. In portions where the center line 132L of the sulfuric acid pipe 132p is curved, the linear grooves 173u and the linear protrusions 173h are also curved. The width of the linear grooves 173u is shorter than the length of the linear grooves 173u. The width of the linear protrusions 173h is shorter than the length of the linear protrusions 173h. The width of the linear protrusions 173h may be equal to or different from the width of the linear grooves 173u.

[0178] Next, the effects of this embodiment in the case where the processing unit 2 described with reference to FIG. 15 and the like is provided will be described.

[0179] The effects on the water flow path and the solvent flow path are as described above.

[0180] Additionally, in this embodiment, the high-temperature chemical (sulfuric acid and SPM) is guided by the high-temperature chemical flow path 132x toward the substrate W. The high-temperature chemical flow path 132x includes an uneven surface 172 that comes into contact with the high-temperature chemical.

[0181] The uneven surface 172 of the high-temperature chemical flow path 132x includes a recess 172u at least partially filled with air and a protrusion 172h that contacts the high-temperature chemical liquid that contacts the air in the recess 172u. Because the recess 172u is at least partially filled with air, the contact area between the high-temperature chemical liquid and the uneven surface 172 is reduced compared to when the entire recess 172u is filled with high-temperature chemical liquid. Furthermore, because the high-temperature chemical liquid does not or is unlikely to come into contact with the inner surface of the recess 172u, the area in contact with the high-temperature chemical liquid on the uneven surface 172 can be limited. This narrows the area to be cleaned with the cleaning liquid, thereby shortening the cleaning time.

[0182] In this embodiment, all or part of the textured surface 172 is made of fluororesin. Fluororesin is a highly water-repellent material. Whether a liquid droplet on a rough surface adopts the Wenzel or Cassie-Baxter state depends on factors such as the surface tension of the liquid, the surface free energy of the rough surface (solid), and the surface properties of the rough surface. By making the textured surface 172 out of a highly water-repellent material, it is possible to maintain a state in which at least a portion of the recesses 172u is filled with air. This reduces the contact area between the high-temperature chemical liquid and the textured surface 172 while limiting the area in contact with the textured surface 172.

[0183] In this embodiment, high-temperature chemical (high-temperature sulfuric acid) is guided from the sulfuric acid tank 132t to the sulfuric acid pipe 132p (high-temperature chemical pipe). The uneven surface 172 is provided on the inner surface of the sulfuric acid tank 132t. The time that the high-temperature sulfuric acid is in contact with the sulfuric acid tank 132t is longer than the time that the high-temperature sulfuric acid is in contact with the sulfuric acid pipe 132p. Therefore, by reducing the contact area between the high-temperature sulfuric acid and the sulfuric acid tank 132t, it is possible to effectively reduce the amount of contaminants transferred from the sulfuric acid tank 132t to the high-temperature sulfuric acid. In particular, when using a sulfuric acid tank 132t made of fluororesin, it is possible to prevent plasticizers from leaching out and becoming impurities. This problem would not occur if the sulfuric acid tank 132t were made of quartz, but this would increase costs. Therefore, by constructing the sulfuric acid tank 132t from fluororesin, it is possible to reduce costs while also overcoming the problem of impurity (plasticizer) leaching, thereby improving substrate processing quality and increasing yield.

[0184] In this embodiment, SPM, a high-temperature chemical liquid, is generated, and the SPM flows through second chemical liquid nozzle 132, through which the SPM is discharged from outlet 132d. The inner surface of second chemical liquid nozzle 132 is provided with uneven surface 172. When the discharge of SPM from second chemical liquid nozzle 132 is stopped, the SPM accumulates inside second chemical liquid nozzle 132. Impurities (typically, plasticizers) are eluted from second chemical liquid nozzle 132, which is made of fluororesin, into the accumulated SPM. If the SPM is subsequently discharged from second chemical liquid nozzle 132 together with the eluted impurities and supplied to substrate W, this may cause processing defects and reduce product yield. Therefore, by reducing the contact area between the SPM and second chemical liquid nozzle 132, it is possible to effectively reduce the amount of contaminants transferred from second chemical liquid nozzle 132 to the SPM, thereby reducing processing defects.

[0185] In this embodiment, an uneven surface 172 is provided on the inner surface (at least the inner surface of the bent portion) of the sulfuric acid pipe 132p that constitutes the high-temperature chemical flow path 132x. Areas of low liquid fluidity (areas where liquid stagnation or retention occurs) may occur in the bent portion. In such cases, contaminants such as impurities (typically plasticizers) eluted from the resin material (fluororesin such as PTFE or PFA) that constitutes the sulfuric acid pipe 132p may accumulate in the bent portion and flow unexpectedly with the high-temperature chemical. Providing the uneven surface 172 on the inner surface of the bent portion reduces the resistance applied to the high-temperature chemical from the inner surface of the bent portion, thereby minimizing the decrease in the speed of the high-temperature chemical at the bent portion and minimizing the areas where high-temperature chemical stagnation or retention occurs. This reduces impurities and foreign matter that accumulate in such areas and reduces the amount of contaminants that migrate from the inner surface of the bent portion to the high-temperature chemical flowing through the bent portion.

[0186] It should be noted that there are other chemicals besides sulfuric acid and SPM that are supplied to the substrate at temperatures higher than room temperature; for example, phosphoric acid is another example of a chemical that is used at high temperatures.

[0187] Any two or more of the above-described features may be combined. Any two or more of the above-described steps may be combined.

[0188] Although the embodiments of the present invention have been described in detail, these are merely examples used to clarify the technical contents of the present invention, and the present invention should not be construed as being limited to these examples. The spirit and scope of the present invention are limited only by the appended claims.

Claims

1. A substrate processing apparatus comprising: a substrate holder for holding a substrate; a water flow path for guiding water toward the substrate held in the substrate holder; and a solvent flow path for guiding an organic solvent, which is a liquid having a lower surface tension than water, toward the substrate held in the substrate holder, wherein the water flow path includes an uneven surface including a recess at least partially filled with air and a protrusion in contact with the water which is in contact with the air in the recess, and the solvent flow path includes a mirror surface in contact with the organic solvent.

2. The substrate processing apparatus according to claim 1, wherein the uneven surface is made of a fluororesin.

3. The substrate processing apparatus of claim 1 or 2, wherein the water flow path includes a water tank for storing the water and water piping for guiding the water supplied from the water tank, and the uneven surface is provided on the inner surface of the water tank.

4. The substrate processing apparatus of claim 1 or 2, wherein the solvent flow path includes a solvent tank for storing the organic solvent and a solvent pipe for guiding the organic solvent supplied from the solvent tank, and the mirror surface is provided on the inner surface of the solvent tank.

5. The substrate processing apparatus according to claim 1 or 2, wherein the uneven surface is provided at a bent portion of the water flow path.

6. A substrate processing apparatus as described in claim 1 or 2, further comprising a high-temperature chemical flow path that guides a high-temperature chemical liquid that is hotter than room temperature toward the substrate held in the substrate holder, the high-temperature chemical flow path including an uneven surface that includes a recess at least partially filled with air and a protrusion in contact with the high-temperature chemical liquid that is in contact with the air in the recess.

7. The substrate processing apparatus according to claim 6, wherein the uneven surface of the high-temperature chemical flow path is made of a fluororesin.

8. The substrate processing apparatus of claim 6, wherein the high-temperature chemical flow path includes a high-temperature chemical tank for storing the high-temperature chemical, and a high-temperature chemical piping for guiding the high-temperature chemical supplied from the high-temperature chemical tank, and the uneven surface of the high-temperature chemical flow path is provided on an inner surface of the high-temperature chemical tank.

9. The substrate processing apparatus according to claim 8, wherein the uneven surface is provided at a bent portion of the high-temperature chemical flow path.

10. The substrate processing apparatus of claim 6, wherein the high-temperature chemical flow path includes a high-temperature chemical piping that guides the high-temperature chemical, and a high-temperature chemical nozzle that discharges the high-temperature chemical guided by the high-temperature chemical piping, and the uneven surface of the high-temperature chemical flow path is provided on an inner surface of the high-temperature chemical nozzle.

11. The substrate processing apparatus according to claim 10, wherein the uneven surface is provided at a bent portion of the high-temperature chemical flow path.

12. A substrate processing method comprising: a water supplying step of guiding water toward a substrate held in a substrate holder through a water flow path including the uneven surface, with at least a portion of the concaves of the uneven surface being filled with air and the convex portions of the uneven surface being in contact with water which is in contact with the air in the concaves; and a solvent supplying step of guiding the organic solvent toward the substrate held in the substrate holder through a solvent flow path including the mirror surface, before or after the water supplying step, with a mirror surface in contact with an organic solvent, which is a liquid having a lower surface tension than the water.

13. A substrate processing method as described in claim 12, further comprising a high-temperature chemical supplying step of guiding a high-temperature chemical liquid that is hotter than room temperature toward a substrate held in a substrate holder, said high-temperature chemical supplying step including a step of circulating the high-temperature chemical liquid through a high-temperature chemical flow path including the uneven surface in a state in which at least a portion of the recesses of the uneven surface are filled with air and the convex portions of the uneven surface are in contact with the high-temperature chemical liquid that is in contact with the air in the recesses.

14. A substrate processing apparatus comprising: a substrate holder for holding a substrate; and a high-temperature chemical flow path for guiding a high-temperature chemical liquid that is hotter than room temperature toward the substrate held in the substrate holder, wherein the high-temperature chemical flow path includes an uneven surface including a recess at least partially filled with air and a protrusion in contact with the high-temperature chemical liquid that is in contact with the air in the recess.

15. The substrate processing apparatus according to claim 14, further comprising a solvent flow path that guides an organic solvent, which is a liquid having a lower surface tension than the high-temperature chemical liquid, toward the substrate held by the substrate holder, the solvent flow path including a mirror surface that contacts the organic solvent.

16. The substrate processing apparatus according to claim 14, wherein the uneven surface is made of a fluororesin.

17. The substrate processing apparatus of claim 14, wherein the high-temperature chemical flow path includes a high-temperature chemical tank for storing the high-temperature chemical, and a high-temperature chemical piping for guiding the high-temperature chemical supplied from the high-temperature chemical tank, and the uneven surface is provided on an inner surface of the high-temperature chemical tank.

18. The substrate processing apparatus of claim 14, wherein the high-temperature chemical flow path includes a high-temperature chemical piping that guides the high-temperature chemical, and a high-temperature chemical nozzle that discharges the high-temperature chemical guided by the high-temperature chemical piping, and the uneven surface is provided on an inner surface of the high-temperature chemical nozzle.

19. The substrate processing apparatus according to claim 17 or 18, wherein the uneven surface is provided at a bent portion of the high-temperature chemical flow path.

20. A substrate processing method comprising a high-temperature chemical supplying step of guiding a high-temperature chemical liquid that is hotter than room temperature toward a substrate held in a substrate holder, the high-temperature chemical supplying step including a step of circulating the high-temperature chemical liquid through a high-temperature chemical liquid flow path including the uneven surface in a state in which at least a portion of the recesses of the uneven surface are filled with air and the convex portions of the uneven surface are in contact with the high-temperature chemical liquid that is in contact with the air in the recesses.

21. The substrate processing method according to claim 20, further comprising a solvent supplying step of guiding the organic solvent, which is a liquid having a lower surface tension than the high-temperature chemical liquid, toward the substrate held by the substrate holder through a solvent flow path including the mirror surface, before or after the high-temperature chemical liquid supplying step, while the mirror surface is in contact with the organic solvent, which is a liquid having a lower surface tension than the high-temperature chemical liquid.

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