Substrate processing method and substrate processing device

Abstract

This substrate processing method comprises: a liquid film formation step for supplying a sublimable-material-containing liquid that contains a sublimable material to a surface of a substrate W, thereby forming a liquid film of the sublimable-material-containing liquid on the surface of the substrate W; a solid film formation step for changing the liquid film of the sublimable-material-containing liquid into a solid film SF containing the sublimable material, on the surface of the substrate W; a sublimation step for sublimating the solid film SF, thereby removing the solid film SF from the surface of the substrate W; and a humidity raising step for raising the humidity of the atmosphere in contact with the substrate W after commencement of the sublimation of the solid film SF.

Description

Substrate processing method and substrate processing apparatus Related Applications

[0001] This application claims priority based on Japanese Patent Application No. 2023-138879 filed on August 29, 2023, the entire contents of which are incorporated herein by reference.

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

[0003] Patent Document 1 discloses that when the solidified material is sublimated and removed from the pattern-formed surface of the substrate, organic matter deposited on the solidified material is removed by using ultraviolet light or ozone gas.

[0004] JP 2018-110199 A

[0005] However, the substrate processing method and substrate processing apparatus described in Patent Document 1 cannot remove organic substances without using ultraviolet light or ozone gas.

[0006] At least one embodiment of the present invention provides a substrate processing method and a substrate processing apparatus capable of removing organic substances generated when a solidified film containing a sublimable substance is sublimated without using ultraviolet rays or ozone gas.

[0007] One embodiment of the present invention provides a substrate processing method, comprising: a liquid film forming step of forming a liquid film of the sublimable substance-containing liquid on the surface of the substrate by supplying a sublimable substance-containing liquid containing a sublimable substance onto the surface of the substrate; a solidified film forming step of changing the liquid film of the sublimable substance-containing liquid on the surface of the substrate into a solidified film containing the sublimable substance; a sublimation step of removing the solidified film from the surface of the substrate by sublimating it; and a humidity increasing step of increasing the humidity of an atmosphere in contact with the substrate after starting sublimation of the solidified film.

[0008] In the above embodiment, at least one of the following features may be added to the substrate processing method.

[0009] The humidity increasing step includes increasing the humidity of an atmosphere in contact with the entire surface of the substrate after sublimation of the solidified film has started.

[0010] The humidity increasing step includes a step of increasing the humidity of an atmosphere in contact with the substrate after sublimation of the solidified film starts and before sublimation of the solidified film ends.

[0011] The humidity increasing step includes a step of discharging a humidified gas having a higher humidity than an atmosphere in contact with the substrate toward the surface of the substrate after sublimation of the solidified film starts.

[0012] The humidity increasing process includes a step of ejecting the humidified gas toward the surface of the substrate after sublimation of the solidified film has started, while the blocking member is positioned at a proximity position where the blocking member faces the surface of the substrate and a standby position where the blocking member faces the surface of the substrate at a position farther from the substrate than when the blocking member is positioned at the proximity position, and the blocking member is movable in parallel in a direction perpendicular to the surface of the substrate between the proximity position and a standby position.

[0013] The humidity increasing process includes a step of ejecting the humidified gas toward the surface of the substrate after sublimation of the solidified film has started, while the blocking member is positioned at a standby position, the blocking member being movable in parallel in a direction perpendicular to the surface of the substrate between a close position where the blocking member faces the surface of the substrate and a standby position where the blocking member faces the surface of the substrate at a position farther from the substrate than when the blocking member is positioned at the close position.

[0014] The humidity increasing process includes a process of moving a humidified gas nozzle that ejects the humidified gas toward the surface of the substrate while the blocking member is positioned at the standby position after sublimation of the solidified film has begun.

[0015] The humidity increasing process includes, after sublimation of the solidified film has begun, a process in which the blocking member, which is movable parallel to the direction perpendicular to the surface of the substrate between a close position where the blocking member faces the surface of the substrate and a standby position where the blocking member faces the surface of the substrate at a position farther from the substrate than when the blocking member is located at the close position, is positioned at the standby position, while rotating the blocking member around a rotation axis passing through the center of the blocking member, and spraying water toward the blocking member from a position on the opposite side of the substrate from the substrate.

[0016] A typical example of the water to be discharged toward the blocking member is pure water. As long as the liquid is primarily composed of water (for example, if the water concentration is 99% or more), the water may contain substances other than water.

[0017] The solidified film forming process includes a process of changing the liquid film of the sublimable substance-containing liquid into the solidified film on the surface of the substrate while supplying an inert gas between the substrate and the blocking member with the blocking member positioned at the close position.

[0018] The sublimable substance is cyclohexanone oxime.

[0019] Another embodiment of the present invention provides a substrate processing apparatus including: a substrate holder for holding a substrate; a sublimable substance-containing liquid nozzle for supplying a sublimable substance-containing liquid containing a sublimable substance onto a surface of the substrate held by the substrate holder, thereby forming a liquid film of the sublimable substance-containing liquid on the surface of the substrate; a gas nozzle for ejecting gas toward the surface of the substrate held by the substrate holder; a spin motor for rotating the substrate held by the substrate holder by rotating the substrate holder around a rotation axis passing through a center of the substrate held by the substrate holder; a humidifier for increasing humidity of an atmosphere in contact with the substrate; and a control device for causing at least one of the gas nozzle and the spin motor to supply the gas to the substrate and / or rotate the substrate, thereby changing the liquid film of the sublimable substance-containing liquid on the surface of the substrate into a solidified film containing the sublimable substance, and then sublimating the solidified film, and after starting sublimation of the solidified film, causing the humidifier to increase humidity of the atmosphere in contact with the substrate. At least one of the above-mentioned features relating to the substrate processing method may be added to the substrate processing apparatus.

[0020] 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.

[0021] 1 is a schematic plan view showing a layout of a substrate processing apparatus according to an embodiment of the present invention; FIG. 2 is a schematic side view of the substrate processing apparatus; FIG. 3 is a schematic view of the interior of a processing unit provided in the substrate processing apparatus, viewed horizontally; FIG. 4 is a schematic view of the interior of the processing unit, viewed from above; FIG. 5 is a schematic view of a gas nozzle, viewed horizontally; FIG. 6 is a schematic cross-sectional view showing a vertical cross-section of a blocking member; FIG. 7 is a block diagram showing the electrical configuration of the substrate processing apparatus; FIG. 8 is a process diagram for explaining an example of substrate processing performed by the substrate processing apparatus; FIG. 9 is a schematic cross-sectional view of a substrate; FIG. 10 is a schematic view for explaining Flow 1, which is a first example of a flow from the start of a sublimation step to the end of a humidity increasing step; FIG. 11 is a schematic view for explaining Flow 1; FIG. 12 is a schematic view for explaining Flow 2, which is a second example of a flow from the start of a sublimation step to the end of a humidity increasing step; FIG. 13 is a schematic view for explaining Flow 2; FIG. 14 is a schematic view for explaining Flow 3;

[0022] In the following description, unless otherwise specified, the air pressure inside the substrate processing apparatus 1 is assumed to be maintained at the air pressure inside the clean room in which the substrate processing apparatus 1 is installed (for example, 1 atmosphere or a value close to that).

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] Next, the processing unit 2 will be described.

[0030] Fig. 2 is a horizontal schematic view of the interior of a processing unit 2 provided in the substrate processing apparatus 1. Fig. 3 is a top schematic view of the interior of the processing unit 2. Fig. 4 is a horizontal schematic view of a gas nozzle 38. Fig. 5 is a vertical schematic cross-sectional view of a blocking member 51. "Sublimation" in Figs. 2 and 5 represents a sublimable substance-containing liquid.

[0031] As shown in Figure 2, the processing unit 2 includes a box-shaped chamber 4 having an internal space, a spin chuck 10 that holds a single substrate W horizontally within the chamber 4 and rotates it around 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 around the rotation axis A1.

[0032] The chamber 4 includes a box-shaped partition 5 provided with an inlet / outlet port 5b through which the substrate W passes, and a shutter 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 air discharged into the exhaust duct 8 is changed depending on the opening degree of an exhaust valve 9 disposed in the exhaust duct 8.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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 31 a and a second chemical liquid nozzle 31 b that discharge chemical liquid toward the upper surface of substrate W, and a first rinse liquid nozzle 35 a and a second rinse liquid nozzle 35 b that discharge rinse liquid toward the upper surface of substrate W. A gas nozzle 38, a center nozzle 55, and a lower surface nozzle 71, which will be described later, are also included in the plurality of nozzles.

[0039] First chemical liquid nozzle 31a may be a scan nozzle that moves the collision position of the chemical liquid on substrate W within the upper surface of substrate W, or may be a fixed nozzle that cannot move the collision position of the chemical liquid on substrate W. The same applies to the other nozzles. Figure 2 shows an example in which first chemical liquid nozzle 31a, second chemical liquid nozzle 31b, first rinse liquid nozzle 35a, second rinse liquid nozzle 35b, and gas nozzle 38 are scan nozzles, and the other nozzles are fixed nozzles.

[0040] First chemical solution nozzle 31a is connected to first chemical solution pipe 32a that guides the chemical solution. Second chemical solution nozzle 31b is connected to second chemical solution pipe 32b that guides the chemical solution. When first chemical solution valve 33a attached to first chemical solution pipe 32a is opened, the chemical solution is continuously discharged downward from the outlet of first chemical solution nozzle 31a. Similarly, when second chemical solution valve 33b attached to second chemical solution pipe 32b is opened, the chemical solution is continuously discharged downward from the outlet of second chemical solution nozzle 31b.

[0041] FIG. 2 shows an example in which the first chemical nozzle 31a dispenses DHF and the second chemical nozzle 31b dispenses SC1. DHF (dilute hydrogen fluoride) represents dilute hydrofluoric acid. SC1 represents a liquid containing ammonium hydroxide, hydrogen peroxide, and water. The chemical dispensed from the first chemical nozzle 31a 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, organic acid (e.g., citric acid, oxalic acid, etc.), organic alkali (e.g., TMAH: tetramethylammonium hydroxide, etc.), surfactant, and corrosion inhibitor, or may be other liquids. The same applies to the chemical dispensed from the second chemical nozzle 31b. The chemical dispensed from the second chemical nozzle 31b is a liquid whose composition and / or temperature are different from those of the chemical dispensed from the first chemical nozzle 31a.

[0042] Although not shown, first chemical liquid valve 33a includes a valve body with an annular valve seat through which the chemical liquid passes, a valve element 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 spaced 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. Control device 3 controls the actuator to open and close first chemical liquid valve 33a, etc.

[0043] The first rinse liquid nozzle 35a is connected to a first rinse liquid pipe 36a that guides the rinse liquid. The second rinse liquid nozzle 35b is connected to a second rinse liquid pipe 36b that guides the rinse liquid. When a first rinse liquid valve 37a attached to the first rinse liquid pipe 36a is opened, the rinse liquid is continuously discharged downward from the discharge port of the first rinse liquid nozzle 35a. Similarly, when a second rinse liquid valve 37b attached to the second rinse liquid pipe 36b is opened, the rinse liquid is continuously discharged downward from the discharge port of the second rinse liquid nozzle 35b.

[0044] FIG. 2 shows an example in which the first rinse liquid nozzle 35a and the second rinse liquid nozzle 35b discharge DIW. DIW (Deionized Water) stands for pure water (deionized water). The rinse liquid discharged from the first rinse liquid nozzle 35a may be any of carbonated water, electrolytic ionized water, hydrogen water, ozone water, and hydrochloric acid water with a diluted concentration (e.g., approximately 10 to 100 ppm), or may be a liquid other than these. The same applies to the rinse liquid discharged from the second rinse liquid nozzle 35b. The rinse liquid discharged from the second rinse liquid nozzle 35b may have the same composition and temperature as the rinse liquid discharged from the first rinse liquid nozzle 35a, or may have a different composition and temperature.

[0045] First chemical liquid nozzle 31 a and first rinse liquid nozzle 35 a are connected to first nozzle movement unit 34 a, which moves first chemical liquid nozzle 31 a and first rinse liquid nozzle 35 a in at least one of the vertical and horizontal directions. First nozzle movement unit 34 a moves first chemical liquid nozzle 31 a and first rinse liquid nozzle 35 a horizontally between a processing position where the processing liquid discharged from first chemical liquid nozzle 31 a or first rinse liquid nozzle 35 a is supplied to the upper surface of substrate W and a standby position where first chemical liquid nozzle 31 a and first rinse liquid nozzle 35 a are positioned around processing cup 21 in a plan view.

[0046] Similarly, second chemical liquid nozzle 31 b and second rinse liquid nozzle 35 b are connected to second nozzle movement unit 34 b, which moves second chemical liquid nozzle 31 b and second rinse liquid nozzle 35 b in at least one of the vertical and horizontal directions. Second nozzle movement unit 34 b moves second chemical liquid nozzle 31 b and second rinse liquid nozzle 35 b horizontally between a processing position where the processing liquid discharged from second chemical liquid nozzle 31 b or second rinse liquid nozzle 35 b is supplied to the upper surface of substrate W and a standby position where second chemical liquid nozzle 31 b and second rinse liquid nozzle 35 b are positioned around processing cup 21 in a plan view.

[0047] The multiple nozzles include a lower surface nozzle 71 that ejects a processing liquid toward the center of the lower surface of the substrate W. The lower surface nozzle 71 includes a disk portion disposed between the upper surface 12u of the spin base 12 and the lower surface of the substrate W, and a cylindrical portion extending downward from the disk portion. The ejection port of the lower surface nozzle 71 opens at the center of the upper surface of the disk portion. When the substrate W is held by the spin chuck 10, the ejection port of the lower surface nozzle 71 faces the center of the lower surface of the substrate W in the vertical direction.

[0048] The lower surface nozzle 71 is connected to a rinse liquid pipe 72 that guides the rinse liquid. Figure 2 shows an example in which the rinse liquid is pure water. When a rinse liquid valve 73 attached to the rinse liquid pipe 72 is opened, the rinse liquid is continuously discharged upward from the discharge port of the lower surface nozzle 71. The temperature of the rinse liquid when discharged from the lower surface nozzle 71 may be equal to or different from room temperature (e.g., 20 to 30°C). In the latter case, the rinse liquid may be heated by a heater 74 before being supplied to the lower surface nozzle 71. In the example shown in Figure 2, warm water (pure water that is hotter than room temperature), which is an example of a heating fluid, is discharged from the lower surface nozzle 71 toward the lower surface of the substrate W.

[0049] The outer peripheral surface of the lower nozzle 71 and the inner peripheral surface of the spin base 12 form a cylindrical gas flow path 82 that extends vertically. The gas flow path 82 includes a central opening 81 that opens at the center of the upper surface 12u of the spin base 12. The gas flow path 82 is connected to an inert gas pipe 83 that guides the inert gas. When an inert gas valve 84 attached to the inert gas pipe 83 is opened, the inert gas is continuously discharged upward from the central opening 81 of the spin base 12 at a flow rate that corresponds to the opening degree of a flow rate adjustment valve 85 that changes the flow rate of the inert gas.

[0050] The inert gas discharged from the central opening 81 of the spin base 12 is nitrogen gas. The inert gas may be a gas other than nitrogen gas, such as helium gas or argon gas. When the substrate W is held by the spin chuck 10, the nitrogen gas is discharged from the central opening 81 of the spin base 12, and the nitrogen gas flows radially in all directions between the lower surface of the substrate W and the upper surface 12u of the spin base 12. This fills the space between the substrate W and the spin base 12 with nitrogen gas.

[0051] The multiple nozzles include a gas nozzle 38 that ejects gas toward the upper surface of the substrate W. The gas nozzle 38 is also an example of a humidified gas nozzle. The gas nozzle 38 is connected to an inert gas pipe 39p that guides an inert gas such as nitrogen gas, and a humidified gas pipe 40p that guides a humidified gas that increases the humidity in the atmosphere in contact with the substrate W. The humidified gas is, for example, nitrogen gas containing atomized water. "Mist" in FIG. 2 represents atomized liquid. This is the same in other figures. The gas contained in the humidified gas may be an inert gas other than nitrogen gas, or a gas other than an inert gas.

[0052] The humidified gas is a wet gas having a higher humidity than the atmosphere in contact with the substrate W. The substrate W comes into contact with clean air supplied from the FFU 6. Therefore, the humidity of the humidified gas is higher than that of the clean air. The temperature of the humidified gas may be equal to or different from room temperature. The humidity of the humidified gas is higher than that of the inert gas guided by the inert gas pipe 39p. The inert gas guided by the inert gas pipe 39p is a dry gas having a lower humidity than the humidified gas. The inert gas guided by pipes other than the inert gas pipe 39p is also a dry gas. The humidified gas has a higher humidity than the dry gas, making it a wet gas.

[0053] The interior of the chamber 4 is filled with clean air supplied from the FFU 6. The substrate W is in contact with the atmosphere inside the chamber 4. The humidity inside the chamber 4 corresponds to the humidity of the atmosphere in contact with the substrate W. When the gas nozzle 38 ejects the humidified gas, the humidity inside the chamber 4 increases to a value at which condensation does not occur on the substrate W. This value varies depending on environmental conditions, including the temperature and air pressure inside the chamber 4 and the temperature and speed of the gas flowing along the substrate W. Therefore, it is sufficient to increase the humidity inside the chamber 4 in accordance with the environmental conditions. For example, the humidity inside the chamber 4 may be increased by about 10%.

[0054] As shown in FIG. 4 , the substrate processing apparatus 1 includes a humidified gas generator that generates humidified gas. The humidified gas generator includes a first liquid tank 91t that stores a liquid, and a first dry gas pipe 91p that supplies dry gas, which has a lower humidity than the humidified gas, into the first liquid tank 91t to atomize the liquid in the first liquid tank 91t. The liquid in the first liquid tank 91t is pure water. The dry gas is nitrogen gas. The liquid in the first liquid tank 91t may be a liquid other than pure water. The dry gas may be a gas other than nitrogen gas.

[0055] The first dry gas pipe 91p is a bubbling pipe including an outlet disposed in the liquid in the first liquid tank 91t. When a dry gas valve 91v attached to the first dry gas pipe 91p is opened, dry gas is discharged from the outlet of the first dry gas pipe 91p, and a large number of bubbles are formed in the liquid in the first liquid tank 91t. The large number of bubbles are released from the surface of the liquid in the first liquid tank 91t into the space within the first liquid tank 91t. At this time, a mist of liquid is generated in the space within the first liquid tank 91t. As a result, dry gas containing a mist of liquid, i.e., humidified gas, is generated in the first liquid tank 91t. The humidified gas in the first liquid tank 91t is supplied to the gas nozzle 38 via the humidified gas pipe 40p.

[0056] When the inert gas valve 39v attached to the inert gas pipe 39p is opened, nitrogen gas is continuously discharged downward from the outlet of the gas nozzle 38 at a flow rate corresponding to the aperture of the flow rate adjustment valve 39f, which changes the flow rate of the inert gas. Similarly, when the humidified gas valve 40v attached to the humidified gas pipe 40p is opened, humidified gas is continuously discharged downward from the outlet of the gas nozzle 38 at a flow rate corresponding to the aperture of the flow rate adjustment valve 40f, which changes the flow rate of the humidified gas. When both the inert gas valve 39v and the humidified gas valve 40v are opened, a mixed gas of nitrogen gas and humidified gas is continuously discharged downward from the outlet of the gas nozzle 38.

[0057] The mixed gas of nitrogen gas and humidified gas has a higher humidity than the atmosphere in contact with the substrate W. The humidity of the mixed gas is higher than that of the nitrogen gas supplied through the inert gas pipe 39p and lower than that of the humidified gas guided through the humidified gas pipe 40p. The humidity of the gas discharged from the gas nozzle 38 is continuously changed within a range from a value equal to the humidity of the nitrogen gas supplied through the inert gas pipe 39p to a value equal to the humidity of the humidified gas guided through the humidified gas pipe 40p by changing the aperture of at least one of the flow rate control valve 39f and the flow rate control valve 40f.

[0058] The gas nozzle 38 is connected to a nozzle moving unit 41 that moves the gas nozzle 38 in at least one of the vertical and horizontal directions. The nozzle moving unit 41 moves the gas nozzle 38 horizontally between a processing position (position indicated by a two-dot chain line in FIG. 3 ) where gas discharged from the gas nozzle 38 is supplied to the upper surface of the substrate W, and a standby position (position indicated by a solid line in FIG. 3 ) where the gas nozzle 38 is positioned around the processing cup 21 in a plan view.

[0059] The nozzle movement unit 41 rotates the gas nozzle 38 around a vertical line located outside the processing cup 21, thereby moving the gas nozzle 38 horizontally along an arc-shaped path that passes through the center of the substrate W in a planar view. Because the radius of the arc-shaped path is large, the gas nozzle 38 moves horizontally along a path that can be considered a straight line in a planar view. The nozzle movement unit 41 may translate the gas nozzle 38 horizontally instead of rotating it.

[0060] The nozzle movement unit 41 includes an actuator 41c that generates power to move the gas nozzle 38 between the processing position and the standby position, and a nozzle arm 41r that transmits the power of the actuator 41c to the gas nozzle 38. The nozzle arm 41r is an example of a transmission element that transmits the power of the actuator 41c to the gas nozzle 38. The gas nozzle 38 extends downward from the tip of the nozzle arm 41r. The gas nozzle 38 may be integral with the nozzle arm 41r, or may be a separate member fixed to the nozzle arm 41r.

[0061] The actuator 41c is a device that converts driving energy, such as electrical, fluid, magnetic, thermal, or chemical energy, into mechanical work. The actuator 41c includes an electric motor (rotary motor), a linear motor, an air cylinder, and other devices. When the actuator 41c is an electric motor that translates the gas nozzle 38 horizontally, the rotation of the actuator 41c may be converted into linear motion of the gas nozzle 38 by a motion converter such as a ball screw and ball nut. The contents of this paragraph also apply to other actuators.

[0062] As shown in Figure 2, the processing unit 2 includes a blocking member 51 arranged above the spin chuck 10. Figure 2 shows an example in which the blocking member 51 is a disk-shaped blocking plate. The blocking member 51 includes a disk portion 52 arranged horizontally above the spin chuck 10. The blocking member 51 is supported horizontally by a cylindrical support shaft 53 extending upward from the center of the disk portion 52. The center line of the disk portion 52 is located on the rotation axis A1 of the substrate W. The lower surface of the disk portion 52 corresponds to the lower surface 51L of the blocking member 51. The lower surface 51L of the blocking member 51 is parallel to the upper surface of the substrate W and has an outer diameter equal to or greater than the diameter of the substrate W.

[0063] The blocking member 51 is connected to a vertical actuator 54v that moves the blocking member 51 vertically in parallel. The vertical actuator 54v positions the blocking member 51 at any position within a range from the upper position (the position shown in FIG. 2 ) to the lower position. The lower position is a proximity position where the lower surface 51L of the blocking member 51 is close to the upper surface of the substrate W to a height at which a scan nozzle such as the first chemical solution nozzle 31a cannot enter between the substrate W and the blocking member 51. The upper position is a standby position where the blocking member 51 is retracted to a height at which a scan nozzle can enter between the blocking member 51 and the substrate W. The intermediate position, which will be described later, is a position between the upper and lower positions at which a scan nozzle cannot enter between the substrate W and the blocking member 51.

[0064] The blocking member 51 is further connected to a rotation actuator 54r that rotates the blocking member 51 about a vertical rotation axis A1 that passes through the center of the blocking member 51. The rotation axis A1 of the blocking member 51 is the same axis as the rotation axis A1 of the substrate W. As shown in FIG. 5 , the blocking member 51 is supported by a support arm 54s via the rotation actuator 54r. The rotation actuator 54r rotates the blocking member 51 relative to the support arm 54s. The vertical actuator 54v raises and lowers the support arm 54s, thereby raising and lowering the blocking member 51. The support arm 54s is disposed above the disk portion 52 of the blocking member 51.

[0065] The substrate processing apparatus 1 includes a cleaning liquid nozzle 50 that ejects a cleaning liquid toward a blocking member 51. FIG. 5 shows an example in which the cleaning liquid is pure water. The cleaning liquid may be a liquid other than pure water. Specific examples of the cleaning liquid are the same as the specific examples of the rinse liquid. The cleaning liquid nozzle 50 is disposed above the blocking member 51. The cleaning liquid nozzle 50 is supported by a support arm 54s via a support bracket 50b. The cleaning liquid nozzle 50 moves up and down together with the blocking member 51. Even if the blocking member 51 rotates, the cleaning liquid nozzle 50 does not rotate.

[0066] The cleaning liquid nozzle 50 is connected to a cleaning liquid pipe 50p that guides the cleaning liquid. When a cleaning liquid valve 50v attached to the cleaning liquid pipe 50p is opened, the cleaning liquid is continuously discharged downward from the discharge port of the cleaning liquid nozzle 50. The temperature of the cleaning liquid when discharged from the cleaning liquid nozzle 50 may be equal to or different from room temperature. In the latter case, the cleaning liquid before being supplied to the cleaning liquid nozzle 50 may be heated by a heater 50h. The cleaning liquid nozzle 50 discharges the cleaning liquid toward the upper surface of the disk portion 52, which corresponds to the upper surface of the blocking member 51. Figure 5 shows an example in which the direction in which the cleaning liquid nozzle 50 discharges the cleaning liquid is tilted toward the rotation axis A1 of the blocking member 51 with respect to the vertical direction.

[0067] The multiple nozzles include a central nozzle 55 that discharges a processing fluid, such as a processing liquid or a processing gas, downward through a central opening 61 that opens in the center of the lower surface 51L of the blocking member 51. The central nozzle 55 extends vertically along the rotation axis A1. The inner circumferential surface of the blocking member 51 surrounds the outer circumferential surface of the center nozzle 55 at a distance. The inner circumferential surface of the blocking member 51 forms a flow path extending upward from the central opening 61. The central nozzle 55 moves up and down together with the blocking member 51. The outlet of the central nozzle 55, which discharges the processing fluid, is located above the central opening 61 of the blocking member 51. The central nozzle 55 and the central opening 61 are examples of a gas nozzle. The central nozzle 55 is also an example of a humidifying gas nozzle.

[0068] The central nozzle 55 includes multiple inner tubes that discharge the treatment fluid downward and a cylindrical casing 55d that surrounds the multiple inner tubes. Figure 5 shows an example in which three inner tubes, namely, a first tube 55a, a second tube 55b, and a third tube 55c, are provided. The inner circumferential surface of the blocking member 51 surrounds the outer circumferential surface of the casing 55d with a gap therebetween. The outer circumferential surface of the casing 55d corresponds to the outer circumferential surface of the central nozzle 55. The outlets of the first tube 55a, the second tube 55b, and the third tube 55c correspond to the outlets of the central nozzle 55.

[0069] The first tube 55a is connected to a sublimable substance-containing liquid pipe 42 that guides the sublimable substance-containing liquid. The second tube 55b is connected to a substitution liquid pipe 44 that guides the substitution liquid. The third tube 55c is connected to a humidified gas pipe 56 that guides the humidified gas. The first tube 55a is an example of a sublimable substance-containing liquid nozzle. The second tube 55b is an example of a substitution liquid nozzle. The third tube 55c is an example of a gas nozzle and a humidification nozzle. FIG. 5 shows an example in which the substitution liquid is IPA (isopropyl alcohol).

[0070] As described above, the substrate processing apparatus 1 includes a humidified gas generator that generates humidified gas. The humidified gas generator includes a second liquid tank 92t that stores a liquid, and a second dry gas pipe 92p that supplies dry gas, which has a lower humidity than the humidified gas, into the second liquid tank 92t to atomize the liquid in the second liquid tank 92t. The liquid in the second liquid tank 92t is pure water. The dry gas is nitrogen gas. The liquid in the second liquid tank 92t may be a liquid other than pure water. The dry gas may be a gas other than nitrogen gas.

[0071] The second dry gas pipe 92p is a bubbling pipe including an outlet disposed in the liquid in the second liquid tank 92t. When the dry gas valve 92v attached to the second dry gas pipe 92p is opened, dry gas is discharged from the outlet of the second dry gas pipe 92p, and numerous bubbles are formed in the liquid in the second liquid tank 92t. The numerous bubbles are released from the surface of the liquid in the second liquid tank 92t into the space within the second liquid tank 92t. At this time, a mist of liquid is generated in the space within the second liquid tank 92t. As a result, dry gas containing a mist of liquid, i.e., humidified gas, is generated in the second liquid tank 92t. The humidified gas in the second liquid tank 92t is supplied to the third tube 55c via the humidified gas pipe 56.

[0072] When the sublimable substance-containing liquid valve 43 attached to the sublimable substance-containing liquid pipe 42 is opened, the sublimable substance-containing liquid is continuously discharged downward from the outlet of the first tube 55 a. Similarly, when the substitution liquid valve 45 attached to the substitution liquid pipe 44 is opened, the substitution liquid is continuously discharged downward from the outlet of the second tube 55 b. When the humidified gas valve 57 attached to the humidified gas pipe 56 is opened, the humidified gas is continuously discharged downward from the outlet of the third tube 55 c at a flow rate corresponding to the opening of the flow rate adjustment valve 58 that changes the flow rate of the humidified gas.

[0073] The sublimable substance-containing liquid is a solution containing a sublimable substance corresponding to a solute and a solvent that dissolves in the sublimable substance. The sublimable substance-containing liquid may be a melt of the sublimable substance (liquid sublimable substance). The sublimable substance-containing liquid may further contain a substance other than the sublimable substance and the solvent. The sublimable substance may be a substance that changes from a solid to a gas without passing through a liquid state at room temperature (synonymous with room temperature) or normal pressure (pressure inside the substrate processing apparatus 1, for example, 1 atmosphere or a value thereabout).

[0074] The freezing point of the sublimable substance-containing liquid (freezing point at 1 atmosphere; the same applies below) is lower than room temperature (for example, 20 to 30°C). The substrate processing apparatus 1 is placed in a clean room maintained at room temperature. Therefore, the sublimable substance-containing liquid can be maintained in a liquid state without heating the sublimable substance-containing liquid. The freezing point of the sublimable substance is higher than the freezing point of the sublimable substance-containing liquid. The freezing point of the sublimable substance is higher than room temperature. At room temperature, the sublimable substance is solid. The freezing point of the sublimable substance may be higher than the boiling point of the solvent. The vapor pressure of the solvent is higher than the vapor pressure of the sublimable substance.

[0075] The sublimable substance may be, for example, any of alcohols such as 2-methyl-2-propanol (also known as tert-butyl alcohol, t-butyl alcohol, or tertiary butyl alcohol) and cyclohexanol, fluorohydrocarbon compounds, 1,3,5-trioxane (also known as metaformaldehyde), camphor (also known as camphor), naphthalene, and iodine, or may be a substance other than these. The sublimable substance may also be cyclohexanone oxime, pinacoline oxime, or acetophenone oxime.

[0076] The solvent may be at least one selected from the group consisting of pure water, IPA, methanol, HFE (hydrofluoroether), acetone, PGMEA (propylene glycol monomethyl ether acetate), PGEE (propylene glycol monoethyl ether, 1-ethoxy-2-propanol), and ethylene glycol. IPA has a higher vapor pressure than water and a lower surface tension than water.

[0077] As will be described later, the substitute liquid is supplied to the upper surface of the substrate W covered with a liquid film of the rinse liquid, and the sublimable substance-containing liquid is supplied to the upper surface of the substrate W covered with a liquid film of the substitute liquid. The substitute liquid may be any liquid as long as it is soluble in both the rinse liquid and the sublimable substance-containing liquid. The substitute liquid is, for example, IPA (liquid). The substitute liquid may be a mixture of IPA and HFE, or may be other liquids.

[0078] As shown in Fig. 5, the inner peripheral surface of the shutoff member 51 and the outer peripheral surface of the central nozzle 55 form a cylindrical gas flow path 62 extending vertically. The gas flow path 62 is connected to an inert gas pipe 63 that guides inert gas. When an inert gas valve 64 attached to the inert gas pipe 63 is opened, inert gas is continuously discharged downward from the central opening 61 of the shutoff member 51 at a flow rate corresponding to the opening of a flow rate adjustment valve 65 that changes the flow rate of the inert gas. The inert gas discharged from the central opening 61 of the shutoff member 51 is nitrogen gas. The inert gas may be a gas other than nitrogen gas, such as helium gas or argon gas.

[0079] The substrate processing apparatus 1 includes a humidifier 90 that increases the humidity of an atmosphere in contact with the substrate W. The gas nozzle 38 shown in FIG. 4 and other figures is included in the humidifier 90. Elements arranged on a path from the first dry gas pipe 91p to the gas nozzle 38, such as a first liquid tank 91t, are also included in the humidifier 90. Similarly, the center nozzle 55 shown in FIG. 5 and other figures is also included in the humidifier 90. Elements arranged on a path from the second dry gas pipe 92p to the center nozzle 55, such as a second liquid tank 92t, are also included in the humidifier 90.

[0080] The cleaning liquid nozzle 50 and the lower surface nozzle 71 are included in the humidifier 90. The cleaning liquid nozzle 50 and the lower surface nozzle 71 are an example of a liquid column nozzle that changes a liquid into a plurality of droplets by colliding the liquid with a rotating body such as the blocking member 51 or the substrate W. When the cleaning liquid nozzle 50 ejects a liquid, a liquid column is formed extending from the ejection port of the cleaning liquid nozzle 50 to the blocking member 51. Similarly, when the lower surface nozzle 71 ejects a liquid, a liquid column is formed extending from the ejection port of the lower surface nozzle 71 to the substrate W. Each element arranged on the path from the cleaning liquid pipe 50p to the cleaning liquid nozzle 50 is also included in the humidifier 90. Similarly, each element arranged on the path from the rinse liquid pipe 72 to the lower surface nozzle 71 is also included in the humidifier 90.

[0081] Next, the electrical configuration of the substrate processing apparatus 1 will be described.

[0082] 6 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.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] Next, an example of processing of the substrate W will be described.

[0088] 7 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.

[0089] The substrate W to be processed is, for example, a semiconductor wafer such as a silicon wafer. The substrate W may be a substrate W having a pattern P1 (see FIG. 8A ) formed on its surface, or a substrate W having no pattern P1 formed on its surface. In the latter case, the pattern P1 may be formed in a first chemical liquid supplying step or a second chemical liquid supplying step, which will be described later. The surface of the substrate W immediately before the sublimable substance-containing liquid is supplied may be either hydrophilic or hydrophobic. The surface of the substrate W may be terminated with at least one of a hydroxyl group and a hydrogen atom, or may be terminated with an atom or atomic group other than these.

[0090] When a substrate W is processed by the substrate processing apparatus 1, a loading step (step S1 in FIG. 7) of loading the substrate W into the chamber 4 is performed.

[0091] Specifically, with the blocking member 51 in the upper position, all guards 24 in the lower position, and all scan nozzles in the standby position, the center robot CR (see FIG. 1A ) supports the substrate W with the hand Hc and causes the hand Hc to enter the chamber 4. The center robot CR then places the substrate W on the hand Hc onto the multiple chuck pins 11 with the front surface of the substrate W facing upward. The multiple chuck pins 11 are then pressed against the edge surface of the substrate W to grip the substrate W. After placing the substrate W on the spin chuck 10, the center robot CR then retracts the hand Hc from the interior of the chamber 4.

[0092] Next, the inert gas valve 84 is opened, and the central opening 81 of the spin base 12 begins to discharge nitrogen gas. This fills the space between the substrate W and the spin base 12 with nitrogen gas. Meanwhile, the guard lifting unit 27 raises at least one guard 24 from the lower position to the upper position. Thereafter, the spin motor 14 is driven, and the rotation of the substrate W begins (step S2 in FIG. 7 ). Similarly, the rotation actuator 54r is driven, and the rotation of the blocking member 51 begins. The rotation speed and rotation direction of the blocking member 51 are controlled to match the rotation speed and rotation direction of the substrate W until the rotation of the substrate W is stopped.

[0093] Next, a first chemical liquid supplying step (step S3 in FIG. 7) is performed in which DHF, an example of a chemical liquid, is supplied to the upper surface of the substrate W to form a liquid film of DHF covering the entire upper surface of the substrate W.

[0094] Specifically, with blocking member 51 in the upper position and at least one guard 24 in the upper position, first nozzle movement unit 34a moves first chemical liquid nozzle 31a and first rinse liquid nozzle 35a from the standby position to the processing position. Thereafter, first chemical liquid valve 33a is opened, and first chemical liquid nozzle 31a begins to discharge DHF. When a predetermined time has elapsed since first chemical liquid valve 33a was opened, first chemical liquid valve 33a is closed, and the discharge of DHF is stopped.

[0095] The DHF discharged from the first chemical liquid nozzle 31a collides with the upper surface of the substrate W rotating at the first chemical liquid supply speed, and then flows outward along the upper surface of the substrate W due to centrifugal force. As a result, the DHF is supplied to the entire upper surface of the substrate W, and a liquid film of DHF is formed covering the entire upper surface of the substrate W. While the first chemical liquid nozzle 31a is discharging the DHF, the first nozzle movement unit 34a may move the collision position of the DHF against the upper surface of the substrate W so that the collision position passes through the center and the outer periphery, or may keep the collision position stationary at the center. Whether or not the collision position is moved applies similarly to the processing liquid supplied to the upper surface of the substrate W after the DHF.

[0096] Next, a first rinse liquid supplying step (step S4 in FIG. 7) is performed in which pure water, which is an example of a rinse liquid, is supplied to the upper surface of the substrate W to wash away the DHF on the substrate W.

[0097] Specifically, with the blocking member 51 in the upper position, at least one guard 24 in the upper position, and the first chemical liquid nozzle 31 a and the first rinse liquid nozzle 35 a in the processing position, the first rinse liquid valve 37 a is opened, and the first rinse liquid nozzle 35 a starts to discharge deionized water. Before the discharge of deionized water starts, the guard lifting unit 27 may vertically move at least one guard 24 to switch the guard 24 that receives the liquid discharged from the substrate W.

[0098] The deionized water discharged from the first rinse liquid nozzle 35a collides with the upper surface of the substrate W, which is rotating at the first rinse liquid supply speed, and then flows outward along the upper surface of the substrate W due to centrifugal force. DHF on the substrate W is replaced with the deionized water discharged from the first rinse liquid nozzle 35a. This forms a liquid film of deionized water that covers the entire upper surface of the substrate W. When a predetermined time has elapsed since the first rinse liquid valve 37a was opened, the first rinse liquid valve 37a is closed, and the discharge of deionized water is stopped. Thereafter, the first nozzle moving unit 34a moves the first chemical liquid nozzle 31a and the first rinse liquid nozzle 35a to their standby positions.

[0099] Next, a second chemical liquid supplying step (step S5 in FIG. 7) is performed in which SC1, an example of a chemical liquid, is supplied to the upper surface of the substrate W to form a liquid film of SC1 covering the entire upper surface of the substrate W.

[0100] Specifically, with blocking member 51 in the upper position and at least one guard 24 in the upper position, second nozzle moving unit 34b moves second chemical liquid nozzle 31b and second rinse liquid nozzle 35b from the standby position to the processing position. Then, second chemical liquid valve 33b is opened, and second chemical liquid nozzle 31b starts discharging SC1. Before discharging SC1 starts, guard lifting unit 27 may move at least one guard 24 vertically to switch the guard 24 that receives the liquid discharged from substrate W.

[0101] SC1 discharged from second chemical liquid nozzle 31b collides with the upper surface of substrate W rotating at the second chemical liquid supply speed, and then flows outward along the upper surface of substrate W due to centrifugal force. The pure water on substrate W is replaced with SC1 discharged from second chemical liquid nozzle 31b. This forms a liquid film of SC1 that covers the entire upper surface of substrate W. When a predetermined time has elapsed since second chemical liquid valve 33b was opened, second chemical liquid valve 33b is closed, and the discharge of SC1 is stopped.

[0102] Next, a second rinse liquid supplying step (step S6 in FIG. 7) is performed in which pure water, which is an example of a rinse liquid, is supplied to the upper surface of the substrate W to wash away SC1 on the substrate W.

[0103] Specifically, with the blocking member 51 in the upper position, at least one guard 24 in the upper position, and the second chemical liquid nozzle 31 b and the second rinse liquid nozzle 35 b in the processing position, the second rinse liquid valve 37 b is opened, and the second rinse liquid nozzle 35 b starts to discharge deionized water. Before the discharge of deionized water starts, the guard lifting unit 27 may vertically move at least one guard 24 to switch the guard 24 that receives the liquid discharged from the substrate W.

[0104] The deionized water discharged from the second rinse liquid nozzle 35b collides with the upper surface of the substrate W, which is rotating at the second rinse liquid supply speed, and then flows outward along the upper surface of the substrate W due to centrifugal force. SC1 on the substrate W is replaced with the deionized water discharged from the second rinse liquid nozzle 35b. This forms a liquid film of deionized water that covers the entire upper surface of the substrate W. When a predetermined time has elapsed since the second rinse liquid valve 37b was opened, the second rinse liquid valve 37b is closed, and the discharge of deionized water is stopped. Thereafter, the second nozzle moving unit 34b moves the second chemical liquid nozzle 31b and the second rinse liquid nozzle 35b to their standby positions.

[0105] Next, a substitute liquid supplying step (step S7 in FIG. 7) is performed in which IPA, which is an example of a substitute liquid, is supplied to the upper surface of the substrate W to replace the pure water on the substrate W with IPA.

[0106] Specifically, with at least one guard 24 in the upper position, the vertical actuator 54v lowers the blocking member 51 to an intermediate position between the upper and lower positions. In this state, the replacement liquid valve 45 is opened, and the central nozzle 55 starts to discharge IPA. Before the discharge of IPA starts, the guard lifting unit 27 may vertically move at least one guard 24 to switch the guard 24 that receives the liquid discharged from the substrate W.

[0107] The IPA discharged from the central nozzle 55 collides with the upper surface of the substrate W, which is rotating at the substitution liquid supply speed, and then flows outward along the upper surface of the substrate W due to centrifugal force. The pure water on the substrate W is replaced with the IPA discharged from the central nozzle 55. As a result, a liquid film of IPA is formed covering the entire upper surface of the substrate W. When a predetermined time has elapsed since the substitution liquid valve 45 was opened, the substitution liquid valve 45 is closed, and the discharge of IPA is stopped. After the liquid film of IPA covering the entire upper surface of the substrate W is formed, the substrate W may be rotated at a paddle speed (for example, a speed greater than 0 rpm but not greater than 20 rpm) while the discharge of IPA from the central nozzle 55 is stopped.

[0108] Next, a sublimable substance-containing liquid supplying step (step S8 in FIG. 7) is performed in which a sublimable substance-containing liquid is supplied to the upper surface of the substrate W to form a liquid film of the sublimable substance-containing liquid covering the entire upper surface of the substrate W.

[0109] Specifically, with the blocking member 51 located at the intermediate position and at least one guard 24 located at the upper position, the sublimable substance-containing liquid valve 43 is opened and the central nozzle 55 starts to discharge the sublimable substance-containing liquid. Before the discharge of the sublimable substance-containing liquid starts, the guard lifting / lowering unit 27 may vertically move at least one guard 24 to switch the guard 24 that receives the liquid discharged from the substrate W.

[0110] The sublimable substance-containing liquid discharged from the central nozzle 55 collides with the upper surface of the substrate W rotating at the sublimable substance supply speed, and then flows outward along the upper surface of the substrate W by centrifugal force. The IPA on the substrate W is replaced with the sublimable substance-containing liquid discharged from the central nozzle 55. This forms a liquid film of the sublimable substance-containing liquid that covers the entire upper surface of the substrate W. When a predetermined time has elapsed since the sublimable substance-containing liquid valve 43 was opened, the sublimable substance-containing liquid valve 43 is closed, and the discharge of the sublimable substance-containing liquid is stopped.

[0111] Next, a film thickness reduction step (step S9 in FIG. 7) is performed in which a portion of the sublimable substance-containing liquid on the substrate W is removed, thereby reducing the film thickness (thickness of the liquid film) of the sublimable substance-containing liquid on the substrate W while maintaining the entire upper surface of the substrate W covered with a liquid film of the sublimable substance-containing liquid.

[0112] Specifically, with the blocking member 51 positioned at the intermediate position, the spin motor 14 maintains the rotation speed of the substrate W at the film thickness reduction speed. The film thickness reduction speed may be equal to or different from the sublimable substance supply speed. The sublimable substance-containing liquid on the substrate W is discharged outward from the substrate W by centrifugal force even after the discharge of the sublimable substance-containing liquid has stopped. Therefore, the thickness of the liquid film of the sublimable substance-containing liquid on the substrate W decreases. When a certain amount of the sublimable substance-containing liquid on the substrate W has been discharged, the amount of the sublimable substance-containing liquid discharged from the substrate W per unit time decreases to zero or approximately zero. As a result, the thickness of the liquid film of the sublimable substance-containing liquid on the substrate W stabilizes at a value corresponding to the rotation speed of the substrate W.

[0113] Next, a solidified film forming process (step S10 in FIG. 7) is performed in which the solvent is evaporated from the sublimable substance-containing liquid on the substrate W to form a solidified film SF (see FIG. 8B) containing the sublimable substance on the substrate W.

[0114] Specifically, with at least one guard 24 in the upper position, the vertical actuator 54v lowers the blocking member 51 to the lower position. Simultaneously with, before, or after the blocking member 51 reaches the lower position, the inert gas valve 64 is opened, and the central opening 61 of the blocking member 51 begins to discharge nitrogen gas. Furthermore, simultaneously with, before, or after the blocking member 51 reaches the lower position, the spin motor 14 increases the rotation speed of the substrate W from the film thickness reduction speed to the solidified film formation speed. The solidified film formation speed may be equal to or different from the sublimable material supply speed.

[0115] When the rotation of the substrate W at the solidified film formation speed is started, the evaporation of the sublimable substance-containing liquid is promoted. Since the vapor pressure of the solvent is higher than the vapor pressure of the sublimable substance corresponding to the solute, the solvent evaporates at a rate higher than the evaporation rate of the sublimable substance. Therefore, the concentration of the sublimable substance gradually increases, while the film thickness of the sublimable substance-containing liquid gradually decreases. When the freezing point of the sublimable substance-containing liquid coincides with the temperature of the sublimable substance-containing liquid, the sublimable substance-containing liquid begins to solidify, and a solidified film SF corresponding to the solidified body covering the entire upper surface of the substrate W is formed.

[0116] Next, a sublimation step is performed in which the solidified film SF on the substrate W is sublimated and removed from the upper surface of the substrate W.

[0117] Specifically, sublimation of the solidified film SF starts (step S11 in FIG. 7 ), and the humidity starts to increase (step S12 in FIG. 7 ). Thereafter, sublimation of the solidified film SF ends (step S13 in FIG. 7 ), and the humidity increase stops (step S14 in FIG. 7 ). Thereafter, rotation of the substrate W and the blocking member 51 is stopped (step S15 in FIG. 7 ). The steps from step S11 in FIG. 7 to step S13 in FIG. 7 correspond to the sublimation step. The steps from step S12 in FIG. 7 to step S14 in FIG. 7 are a humidity increase step for increasing the humidity of the atmosphere in contact with the substrate W. Details of the sublimation step and the humidity increase step will be described later.

[0118] Next, an unloading step (step S16 in FIG. 7) is performed to unload the substrate W from the chamber 4.

[0119] Specifically, the vertical actuator 54v raises the blocking member 51 to the upper position, and the guard lifting unit 27 lowers all of the guards 24 to the lower position. Furthermore, the inert gas valve 64 and the inert gas valve 84 are closed, and the central opening 61 of the blocking member 51 and the central opening 81 of the spin base 12 stop discharging nitrogen gas. The center robot CR then causes the hand Hc to enter the chamber 4. After the chuck pins 11 release their grip on the substrate W, the center robot CR supports the substrate W on the spin chuck 10 with the hand Hc. The center robot CR then retracts the hand Hc from the inside of the chamber 4 while still supporting the substrate W with the hand Hc. This causes the processed substrate W to be removed from the chamber 4.

[0120] Next, a phenomenon that occurs on the surface of the substrate W from when the liquid film of the sublimable substance-containing liquid is transformed into the solidified film SF until when the solidified film SF is removed will be described.

[0121] 8A to 8E are schematic cross-sectional views of a substrate W. 8A to 8E show cross sections of the front surface of the substrate W on which a pattern P1 has been formed. Before the pattern P1 is formed, the substrate W includes a front surface and a back surface that are parallel to each other and are circular, and an annular end surface that connects the outer edges of the front surface and the back surface. The front surface and the back surface of the substrate W are flat surfaces that are parallel to each other. The front surface of the substrate W is a device formation surface on which devices such as transistors are formed. The back surface of the substrate W is a non-device formation surface on which devices are not formed. Both the front surface and the back surface of the substrate W may be device formation surfaces.

[0122] As shown in Fig. 8A, in the sublimable substance-containing liquid supply step (step S8 in Fig. 7), a liquid film of the sublimable substance-containing liquid is formed to cover the entire surface of the substrate W. As shown in Fig. 8B, in the solidified film formation step (step S10 in Fig. 7), the sublimable substance-containing liquid on the substrate W is transformed into a solidified film SF. Fig. 8B shows an example in which the thickness of the solidified film SF is greater than the height of the pattern P1. The thickness of the solidified film SF may be equal to or less than the height of the pattern P1. As shown in Figs. 8B and 8C, in the sublimation step (steps S11 to S13 in Fig. 7), the solidified film SF is removed from the substrate W by sublimation of the solidified film SF.

[0123] When a solidified film SF containing a sublimable substance is sublimated, residues such as organic matter may be generated from the solidified film SF. The black circles in Figures 8C and 8D represent organic matter. The circles in Figures 8C and 8D merely show images of the organic matter, and the actual shapes of the organic matter may not necessarily match those shown in Figures 8C and 8D. Although Figures 8C and 8D show a substrate W from which all of the solidified film SF has been removed, organic matter is generated before all of the solidified film SF is removed.

[0124] The organic substance may be a sublimable substance that has not sublimated, or may be a substance resulting from a change in the properties of a sublimable substance. The organic substance may be a substance that has sublimability, or may be a substance that does not have sublimability. The organic substance may be an organic compound that contains a hydrophilic group such as a carboxyl group, a hydroxyl group, or a sulfonic acid group, or may be an organic compound that does not contain a hydrophilic group. The organic substance may be at least one of cyclohexanone oxime, cyclohexanone, and caprolactam, or may be an organic compound other than these.

[0125] As shown in FIG. 8D , in the humidity increasing step (steps S12 to S14 in FIG. 7 ), the humidity of the atmosphere in contact with the entire surface of the substrate W is increased. Water molecules in the atmosphere in contact with the surface of the substrate W bond with organic matter on the substrate W generated from the solidified film SF. The water molecules in the atmosphere that have bonded with the organic matter are pushed away from the surface of the substrate W by the air current flowing along the surface of the substrate W. As shown in FIG. 8E , this phenomenon occurs repeatedly in various parts of the surface of the substrate W, which is thought to remove the organic matter generated from the solidified film SF. In fact, it was confirmed that when the humidity of the atmosphere in contact with the substrate W was increased after the start of sublimation of the solidified film SF, the amount of remaining organic matter, such as cyclohexanone oxime, cyclohexanone, and caprolactam, decreased.

[0126] The increase in humidity in the atmosphere in contact with the substrate W begins after sublimation of the solidified film SF begins. If the humidity is increased before sublimation of the solidified film SF begins, moisture in the atmosphere may penetrate into the solidified film SF, and sublimation of the solidified film SF may not begin properly. If the humidity is increased while the liquid film of the sublimable substance-containing liquid is being transformed into the solidified film SF, moisture in the atmosphere may dissolve into the sublimable substance-containing liquid, and the time required to form the solidified film SF may increase. If the humidity is increased after sublimation of the solidified film SF begins, the possibility of such a situation occurring can be eliminated or reduced.

[0127] As long as the sublimation of the solidified film SF is not completed, the increase in humidity of the atmosphere in contact with the substrate W may be started after more than half of the time from the start of sublimation of the solidified film SF to the end of sublimation has elapsed. In this way, since more than half of the solidified film SF has been sublimated, it is possible to remove organic substances while minimizing the effect of the increase in humidity on the sublimation of the solidified film SF. However, as long as the sublimation of the solidified film SF has started, the increase in humidity may be started before half of the time has elapsed. Although different from the example shown in FIG. 7 , the increase in humidity may be started after the sublimation of the solidified film SF is completed.

[0128] Next, a flow from the start of the sublimation step to the end of the humidity increasing step will be described.

[0129] First, a first example of a flow from the start of the sublimation step to the end of the humidity increasing step will be described as Flow 1. Figures 9A, 9B, and 9C are schematic diagrams for explaining Flow 1. Figures 9A to 9C are views of the substrate W viewed horizontally.

[0130] When the solidified film SF is sublimated in flow 1, as shown in Figure 9A, the blocking member 51 is positioned in the lower position, and the central opening 61 of the blocking member 51 is ejecting nitrogen gas downward, while the spin motor 14 maintains the rotation speed of the substrate W at the sublimation speed, and the rotation actuator 54r maintains the rotation speed of the blocking member 51 at the sublimation speed.

[0131] When the rotation of the substrate W at the sublimation speed starts, sublimation of the solidified film SF on the substrate W begins, and a gas containing a sublimable substance is generated from the solidified film SF on the substrate W. The gas (gas containing a sublimable substance) generated from the solidified film SF flows radially in the space between the substrate W and the blocking member 51 and is exhausted from above the substrate W. After a certain amount of time has passed since the start of sublimation, all or almost all of the solidified film SF is removed from the substrate W, as shown in Fig. 9C. This completes the sublimation of the solidified film SF.

[0132] After the sublimation of the solidified film SF begins, in other words, after the rotation speed of the substrate W reaches the sublimation speed, as shown in Figure 9B, the humidified gas valve 57 is opened and the central nozzle 55 (strictly speaking, the third tube 55c shown in Figure 5) begins to discharge humidified gas. At this time, the blocking member 51 is in the lower position, and the substrate W and the blocking member 51 are rotating at the sublimation speed. In addition, the central opening 61 of the blocking member 51 discharges nitrogen gas downward. The inert gas valve 64 may be closed simultaneously with, before, or after the central nozzle 55 begins to discharge humidified gas.

[0133] The humidified gas discharged from the central nozzle 55 flows radially in all directions from the center of the substrate W between the substrate W and the blocking member 51. This fills the space between the substrate W and the blocking member 51 with the humidified gas. While the humidified gas is being discharged, the humidity of the atmosphere in contact with the substrate W is maintained at a value higher than the humidity of the atmosphere before the discharge of the humidified gas began. Organic matter generated as the solidified film SF sublimates is removed from the substrate W by the supply of the humidified gas. The sublimation of the solidified film SF continues even after the nitrogen gas between the substrate W and the blocking member 51 is replaced with the humidified gas. Therefore, the organic matter can be removed while the solidified film SF is being sublimated.

[0134] When a predetermined time has elapsed since the humidified gas valve 57 was opened, the humidified gas valve 57 is closed, and the central nozzle 55 stops discharging the humidified gas. If the central opening 61 of the blocking member 51 is discharging nitrogen gas, the inert gas valve 64 is also closed. After the humidified gas valve 57 is closed, the unloading step (step S16 in FIG. 7) is performed. All or almost all of the solidified film SF has been sublimated before the humidified gas valve 57 is closed. Therefore, organic matter remaining on the substrate W after all or almost all of the solidified film SF has been sublimated can also be removed by the humidified gas.

[0135] Next, a second example of a flow from the start of the sublimation step to the end of the humidity increasing step will be described.

[0136] 10A, 10B, and 10C are schematic diagrams for explaining flow 2. Figures 10A to 10C are views of the substrate W viewed horizontally. In the following description, "the blocking member 51 discharges nitrogen gas downward" means that the central opening 61 of the blocking member 51 discharges nitrogen gas downward.

[0137] When the solidified film SF is sublimated in flow 2, the vertical actuator 54v moves the blocking member 51 from the lower position to the upper position, as shown in Fig. 10A. Thereafter, as shown in Fig. 10B, the nozzle moving unit 41 moves the gas nozzle 38, which is located in the standby position, to between the substrate W and the blocking member 51. Thereafter, the inert gas valve 39v is opened, and the gas nozzle 38 begins to discharge nitrogen gas. Simultaneously with, before, or after the gas nozzle 38 begins to discharge nitrogen gas, the spin motor 14 maintains the rotational speed of the substrate W at the sublimation speed, and the rotary actuator 54r maintains the rotational speed of the blocking member 51 at the sublimation speed.

[0138] When the substrate W starts to rotate at the sublimation speed, sublimation of the solidified film SF on the substrate W begins. Nitrogen gas discharged downward from the gas nozzle 38 toward the solidified film SF promotes sublimation of the solidified film SF. While the solidified film SF is sublimating, the nozzle movement unit 41 may hold the gas nozzle 38 stationary so that the impact position where the nitrogen gas discharged from the gas nozzle 38 first impacts the top surface of the substrate W is fixed at the center of the substrate W, or may move the gas nozzle 38 horizontally so that the impact position passes through the center and the outer periphery. This is also the case in Flow 3, which will be described later.

[0139] 10C , with the blocking member 51 in the upper position and the gas nozzle 38 positioned between the substrate W and the blocking member 51, the humidified gas valve 40v is opened and the gas nozzle 38 begins to discharge the humidified gas. When the humidified gas valve 40v is opened, the inert gas valve 39v may be closed or open. The humidified gas discharged downward from the gas nozzle 38 collides with the substrate W at a collision position on the upper surface of the substrate W, and then flows radially in all directions along the upper surface of the substrate W from the collision position.

[0140] Sublimation of the solidified film SF continues even after the humidity of the gas discharged from the gas nozzle 38 increases. Organic matter generated as the solidified film SF sublimates is removed from the substrate W by supplying humidified gas. While the gas nozzle 38 is discharging the humidified gas, the nozzle movement unit 41 may hold the gas nozzle 38 stationary so that the collision position of the humidified gas with the upper surface of the substrate W is fixed at the center of the substrate W, or may move the gas nozzle 38 horizontally so that the collision position of the humidified gas passes through both the center and the outer periphery.

[0141] When a predetermined time has elapsed since the humidified gas valve 40v was opened, the humidified gas valve 40v is closed, and the gas nozzle 38 stops discharging the humidified gas. If the inert gas valve 64 and the inert gas valve 39v are open, the inert gas valve 39v is also closed. All or almost all of the solidified film SF is sublimated before the humidified gas valve 40v is closed. Simultaneously with, before, or after the humidified gas valve 40v is closed, the nozzle moving unit 41 moves the gas nozzle 38 to the standby position. Thereafter, the carry-out process (step S16 in FIG. 7) is performed. However, since the blocking member 51 is already in the upper position, the raising of the blocking member 51 is omitted.

[0142] Next, a third example of a flow from the start of the sublimation step to the end of the humidity increasing step will be described.

[0143] 11A and 11B are schematic diagrams for explaining flow 3. Figures 11A and 11B are horizontal views of the substrate W. The cross-hatched area in Figure 11A represents the mist of the cleaning liquid.

[0144] When the solidified film SF is sublimated in flow 3, the vertical actuator 54v (see FIG. 2) moves the blocking member 51 from the lower position to the upper position. Then, as shown in FIG. 11A , the nozzle moving unit 41 moves the gas nozzle 38, which is in the standby position, to between the substrate W and the blocking member 51. Then, the inert gas valve 39v is opened, and the gas nozzle 38 begins to discharge nitrogen gas. Simultaneously with, before, or after the gas nozzle 38 begins to discharge nitrogen gas, the spin motor 14 maintains the rotational speed of the substrate W at the sublimation speed, and the rotary actuator 54r maintains the rotational speed of the blocking member 51 at the sublimation speed.

[0145] After the sublimation of the solidified film SF begins, in other words, after the rotation speed of the substrate W reaches the sublimation speed, the cleaning liquid valve 50v is opened and the cleaning liquid nozzle 50 begins to discharge the cleaning liquid, as shown in FIG. 11B . At this time, the blocking member 51 is in the upper position, and the substrate W and the blocking member 51 are rotating at the sublimation speed. In addition, the gas nozzle 38 and the blocking member 51 are discharging nitrogen gas downward. After the sublimation of the solidified film SF begins, humidified gas may be discharged from at least one of the gas nozzle 38 and the center nozzle 55.

[0146] 11B , the cleaning liquid ejected from the cleaning liquid nozzle 50 lands on the upper surface of the rotating blocking member 51 and then flows along the upper surface of the blocking member 51. Most of the cleaning liquid does not fall vertically or nearly vertically from the outer periphery of the upper surface of the blocking member 51, but rather splashes nearly horizontally from the upper surface of the blocking member 51. When the cleaning liquid collides with the blocking member 51, a mist of the cleaning liquid is generated. When the cleaning liquid leaves the blocking member 51 and when the splashing cleaning liquid collides with the inner surface of the chamber 4, a mist of the cleaning liquid is also generated. This increases the humidity inside the chamber 4.

[0147] The clean air flowing downward from the FFU 6 applies a downward force to the mist of cleaning liquid. The airflow passing through the processing cup 21 and entering the exhaust duct 8 applies a force to the mist of cleaning liquid, moving it toward the exhaust duct 8. The nitrogen gas ejected downward from the gas nozzle 38 toward the upper surface of the substrate W generates a force that attracts the mist of cleaning liquid toward the upper surface of the substrate W. The mist of cleaning liquid is supplied over the entire upper surface of the substrate W by these forces. As a result, organic matter generated as the solidified film SF sublimates is removed from the substrate W by the supply of humidified gas.

[0148] When a predetermined time has elapsed since the cleaning liquid valve 50v was opened, the cleaning liquid valve 50v is closed, and the cleaning liquid nozzle 50 stops discharging the cleaning liquid. Simultaneously with, before, or after the cleaning liquid valve 50v is closed, the inert gas valve 39v is closed, and the gas nozzle 38 stops discharging the nitrogen gas. Similarly, the inert gas valve 64 is closed, and the shutoff member 51 stops discharging the nitrogen gas.

[0149] The nitrogen gas discharged from the gas nozzle 38 promotes evaporation of the cleaning liquid mist adhering to the substrate W. The same applies to the nitrogen gas discharged from the blocking member 51. The airflow generated by the rotation of the substrate W also promotes evaporation of the cleaning liquid mist adhering to the substrate W. Therefore, at least one of the gas nozzle 38 and the inert gas valve 64 may stop discharging the nitrogen gas after the cleaning liquid nozzle 50 stops discharging the cleaning liquid. Similarly, the spin motor 14 may stop rotating the substrate W after the cleaning liquid nozzle 50 stops discharging the cleaning liquid.

[0150] The nozzle moving unit 41 moves the gas nozzle 38 to the standby position simultaneously with, before, or after the inert gas valve 39v is closed. Then, the unloading step (step S16 in FIG. 7 ) is performed. However, since the shielding member 51 is already in the upper position, the raising of the shielding member 51 is omitted. Before the substrate W is unloaded from the chamber 4, the shielding member 51 may be dried by rotating it at high speed. For example, before the substrate W is unloaded from the chamber 4, the substrate W and the shielding member 51 may be dried by rotating the shielding member 51 at high speed while rotating the substrate W at high speed.

[0151] Next, the effects of this embodiment will be described.

[0152] In this embodiment, a liquid film of a sublimable substance-containing liquid containing a sublimable substance is formed on the surface of the substrate W, and this liquid film is converted into a solidified film SF containing the sublimable substance. As a result, a solidified film SF containing the sublimable substance is formed on the surface of the substrate W. The solidified film SF is then sublimated and removed from the substrate W. When the solidified film SF is sublimated, organic matter may be generated from the solidified film SF. After the sublimation of the solidified film SF begins, the humidity of the atmosphere in contact with the substrate W is increased. This increases the number of water molecules in the atmosphere. The water molecules in the atmosphere bond with the organic matter and move the organic matter from the substrate W into the atmosphere. This makes it possible to reduce the amount of organic matter remaining on the surface of the substrate W.

[0153] In this embodiment, after the sublimation of the solidified film SF starts, a gas with a relatively high humidity is brought into contact with the entire surface of the substrate W, not just a portion of the surface. Water molecules in the atmosphere come into contact with the entire surface of the substrate W. This increases the amount of organic matter that bonds with water molecules floating in the atmosphere, and reduces the amount of organic matter remaining on the surface of the substrate W.

[0154] In this embodiment, the humidity does not start to increase after the sublimation of the solidified film SF is completed, but starts to increase before the sublimation of the solidified film SF is completed. Therefore, compared to when the humidity starts to increase after the sublimation of the solidified film SF is completed, the time from when organic matter is generated until the organic matter bonds with water molecules in the atmosphere can be shortened. The bonding strength between organic matter and the substrate W may increase over time. In such a case, the organic matter can be effectively removed from the substrate W.

[0155] In this embodiment, humidified gas having a higher humidity than the atmosphere in contact with the substrate W is discharged toward the surface of the substrate W. This increases the humidity of the atmosphere in contact with the substrate W, and allows water molecules in the atmosphere to bond with organic matter adhering to the substrate W. After colliding with the surface of the substrate W, the humidified gas flows along the surface of the substrate W. The organic matter and water molecules that have bonded to each other are carried by the flow of this humidified gas and quickly detach from the substrate W. This reduces the amount of organic matter that re-adheres to the substrate W.

[0156] In this embodiment, the blocking member 51, which is movable in parallel in a direction perpendicular to the surface of the substrate W between the proximity position and the standby position, is positioned at the proximity position. In this state, the humidified gas is discharged toward the surface of the substrate W. Therefore, the speed at which the humidified gas flows along the surface of the substrate W can be increased compared to when the humidified gas is supplied to the surface of the substrate W while the blocking member 51 is positioned at the standby position. The increased speed of the humidified gas allows organic matter and water molecules that have bonded to each other to be quickly removed from the substrate W.

[0157] In this embodiment, the blocking member 51, which is movable in parallel in a direction perpendicular to the surface of the substrate W between the proximity position and the standby position, is positioned at the standby position. In this state, humidified gas is ejected toward the surface of the substrate W. Because the blocking member 51 is farther from the substrate W than when it is positioned at the proximity position, the organic matter and water molecules that have bonded to each other can be moved away from the substrate W in a direction perpendicular to the surface of the substrate W. This makes it possible to reduce organic matter that re-adheses to the surface of the substrate W.

[0158] In this embodiment, after sublimation of the solidified film SF begins, humidified gas is ejected toward the surface of the substrate W from the gas nozzle 38, which is an example of a humidified gas nozzle, while the blocking member 51 is located at the standby position. In this state, the gas nozzle 38 is moved. As the gas nozzle 38 moves, the collision position where the humidified gas first collides with the surface of the substrate W also moves. This allows the humidified gas to directly collide with a wider area on the upper surface of the substrate W. Furthermore, as the collision position of the humidified gas approaches the bonded organic matter and water molecules, the force applied by the humidified gas to the organic matter and water molecules increases. Therefore, the amount of organic matter remaining on the surface of the substrate W can be further reduced compared to when the gas nozzle 38 is not moved.

[0159] In this embodiment, the shielding member 51 is rotated while positioned at the standby position. In this state, pure water is ejected toward the shielding member 51 from a position on the opposite side of the shielding member 51 from the substrate W. The pure water collides with the shielding member 51. This collision generates mist. Furthermore, because the shielding member 51 is rotating, the pure water is scattered from the shielding member 51. This scattering generates mist. This makes it possible to easily create a large amount of mist in a short time. The mist flows through the atmosphere toward the surface of the substrate W. Because the shielding member 51 is positioned at the standby position, mist is more likely to enter between the substrate W and the shielding member 51 than when the shielding member 51 is positioned in the proximity position. This makes it possible to increase the humidity of the atmosphere in contact with the substrate W.

[0160] In this embodiment, with the blocking member 51 positioned at the close position, an inert gas is supplied between the substrate W and the blocking member 51, and the liquid film of the sublimable substance-containing liquid is converted into a solidified film SF. The inert gas flows between the substrate W and the blocking member 51. The airflow toward the surface of the substrate W is blocked by the blocking member 51. Therefore, a solidified film SF can be formed on the surface of the substrate W while stabilizing the airflow along the surface of the substrate W. Furthermore, the speed at which the inert gas flows along the surface of the substrate W can be increased compared to when the inert gas is supplied to the surface of the substrate W while the blocking member 51 is positioned at the standby position. The increased speed of the inert gas can promote the formation of the solidified film SF.

[0161] In this embodiment, a sublimable substance-containing liquid containing cyclohexanone oxime, an example of a sublimable substance, is supplied to the surface of the substrate W, and a solidified film SF containing cyclohexanone oxime is sublimated. When such a solidified film SF is sublimated, at least one of cyclohexanone oxime, cyclohexanone, and caprolactam may be generated from the solidified film SF as an organic substance. When water molecules in the atmosphere approach such organic substances, the organic substances bond with the water molecules and move away from the substrate W. Therefore, by increasing the humidity of the atmosphere in contact with the substrate W after the sublimation of the solidified film SF begins, the organic substances remaining on the surface of the substrate W can be reduced.

[0162] Next, another embodiment will be described.

[0163] Instead of increasing the humidity of the atmosphere in contact with the entire surface of the substrate W, it is also possible to increase the humidity of the atmosphere in contact with only a portion of the surface of the substrate W. For example, while a portion of the surface of the substrate W is protected by at least one of a fluid and a tangible object, humidified gas may be ejected toward the remaining portion of the surface of the substrate W.

[0164] After the sublimation of the solidified film SF is completed, the humidity of the atmosphere in contact with the substrate W may start to increase. The increase in humidity may also be stopped before the sublimation of the solidified film SF is completed.

[0165] After the humidity of the atmosphere in contact with the substrate W is increased, the humidity may be kept constant or may be varied, in which case the humidity of the atmosphere in contact with the substrate W may be varied so as to cause an increasing period or a decreasing period, or to cause at least two of an increasing period, a decreasing period, and a constant period.

[0166] The rising period is a period during which the humidity of the atmosphere in contact with the substrate W continuously increases over time. The falling period is a period during which the humidity of the atmosphere in contact with the substrate W continuously decreases over time. The constant period is a period during which the humidity of the atmosphere in contact with the substrate W is maintained constant.

[0167] The gas nozzle 38 may be a mist nozzle that ejects a liquid such as water in a mist form, or a shower nozzle that ejects a liquid in a shower form. The same applies to the central nozzle 55 (strictly speaking, the third tube 55c).

[0168] The mist nozzle may be an external or internal mixing two-fluid nozzle that generates mist by colliding liquid and gas, or a spray nozzle that generates mist by expelling compressed liquid from an orifice or by utilizing the Venturi effect.

[0169] Instead of discharging nitrogen gas into the central opening 61 of the blocking member 51 and discharging nitrogen gas containing atomized water, which is an example of a humidified gas, into the central nozzle 55, nitrogen gas containing atomized water may be discharged into the central opening 61 of the blocking member 51 and nitrogen gas may be discharged into the central nozzle 55.

[0170] In the above-described flow 1, when the blocking member 51 is in the lower position and the central nozzle 55 is discharging the humidified gas toward the upper surface of the substrate W, the lower surface nozzle 71 may be caused to discharge a rinse liquid such as warm water toward the lower surface of the substrate W. After the sublimation of the solidified film SF is completed, the substrate W may be dried by rotating at high speed while the lower surface nozzle 71 is not discharging the rinse liquid.

[0171] The warm water ejected from the lower surface nozzle 71 collides with the lower surface of the rotating substrate W, and then flows outward along the lower surface of the substrate W. The substrate W is heated by the warm water. This makes it possible to prevent condensation from forming on the upper surface of the substrate W. Furthermore, the humidified gas flowing along the upper surface of the substrate W pushes outward the warm water that would otherwise flow around to the upper surface of the substrate W via the edge of the substrate W, thereby preventing the upper surface of the substrate W from becoming wet with the warm water.

[0172] The substrate processing apparatus 1 is not limited to an apparatus for processing a disk-shaped substrate W, but may be an apparatus for processing a polygonal substrate W.

[0173] Any two or more of the above-described features may be combined. Any two or more of the above-described steps may be combined.

[0174] 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 method comprising: a liquid film forming step of forming a liquid film of sublimable substance-containing liquid on a surface of a substrate by supplying a sublimable substance-containing liquid containing a sublimable substance onto the surface of the substrate; a solidified film forming step of changing the liquid film of the sublimable substance-containing liquid on the surface of the substrate into a solidified film containing the sublimable substance; a sublimation step of removing the solidified film from the surface of the substrate by sublimating it; and a humidity increasing step of increasing the humidity of an atmosphere in contact with the substrate after starting sublimation of the solidified film.

2. The substrate processing method according to claim 1, wherein the humidity increasing step includes a step of increasing the humidity of an atmosphere in contact with the entire surface of the substrate after sublimation of the solidified film starts.

3. A substrate processing method as described in claim 1 or 2, wherein the humidity increasing step includes a step of increasing the humidity of an atmosphere in contact with the substrate after sublimation of the solidified film has started and before sublimation of the solidified film has ended.

4. The substrate processing method according to claim 1, wherein the humidity increasing step includes a step of ejecting a humidified gas having a higher humidity than an atmosphere in contact with the substrate toward the surface of the substrate after sublimation of the solidified film has commenced.

5. A substrate processing method as described in claim 4, wherein the humidity increasing step includes, after starting sublimation of the solidified film, spraying the humidified gas toward the surface of the substrate while the blocking member is positioned at a proximity position where the blocking member faces the surface of the substrate and a standby position where the blocking member faces the surface of the substrate at a position farther away from the substrate than when the blocking member is positioned at the proximity position, and is movable in parallel in a direction perpendicular to the surface of the substrate between the proximity position and a standby position.

6. A substrate processing method as described in claim 4, wherein the humidity increasing step includes, after starting sublimation of the solidified film, a step of ejecting the humidified gas toward the surface of the substrate while the blocking member is positioned at a standby position capable of moving parallel in a direction perpendicular to the surface of the substrate between a close position where the blocking member faces the surface of the substrate and a standby position where the blocking member faces the surface of the substrate at a position farther from the substrate than when the blocking member is positioned at the close position.

7. The substrate processing method of claim 6, wherein the humidity increasing step includes a step of moving a humidified gas nozzle that ejects the humidified gas toward the surface of the substrate while the blocking member is positioned at the standby position after sublimation of the solidified film has commenced.

8. The substrate processing method of claim 1, wherein the humidity increasing step includes, after starting sublimation of the solidified film, a step of injecting water toward the blocking member from a position on the opposite side of the substrate to the blocking member while rotating the blocking member about a rotation axis passing through a center of the blocking member, the blocking member being capable of moving in parallel in a direction perpendicular to the surface of the substrate between a close position where the blocking member faces the surface of the substrate and a standby position where the blocking member faces the surface of the substrate at a position farther from the substrate than when the blocking member is located at the close position, the blocking member being located at the standby position.

9. A substrate processing method according to any one of claims 5 to 8, wherein the solidified film forming process includes a process of changing the liquid film of the sublimable substance-containing liquid into the solidified film on the surface of the substrate while supplying an inert gas between the substrate and the blocking member with the blocking member positioned at the close position.

10. The substrate processing method according to claim 1 or 2, wherein the sublimable substance is cyclohexanone oxime.

11. A substrate processing apparatus comprising: a substrate holder for holding a substrate; a sublimable substance-containing liquid nozzle for supplying a sublimable substance-containing liquid containing a sublimable substance onto a surface of the substrate held by the substrate holder, thereby forming a liquid film of the sublimable substance-containing liquid on the surface of the substrate; a gas nozzle for ejecting gas toward the surface of the substrate held by the substrate holder; a spin motor for rotating the substrate held by the substrate holder by rotating the substrate holder about a rotation axis passing through a center of the substrate held by the substrate holder; a humidifier for increasing humidity of an atmosphere in contact with the substrate; and a control device for causing at least one of the gas nozzle and the spin motor to supply the gas to the substrate and / or rotate the substrate, thereby changing the liquid film of the sublimable substance-containing liquid into a solidified film containing the sublimable substance on the surface of the substrate, and then sublimating the solidified film, and causing the humidifier to increase humidity of the atmosphere in contact with the substrate after starting sublimation of the solidified film.

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