SUBSTRATE PROCESSING METHOD AND SUBSTRATE PROCESSING APPARATUS

Abstract

To provide a substrate processing method and substrate processing apparatus capable of removing an object to be removed with high efficiency while reducing environmental burden.SOLUTION: The gelatinization agent inclusion liquid containing gelatinization agent is supplied to a first principal plane of a substrate W (gelatinization agent inclusion liquid supply process).By cooling a substrate, the gelatinization agent inclusion liquid on the first principal plane changes into a gel film (gelatinization process). By injecting cleaning fluid toward a first principal plane under a formation state of gel, the first principal plane is cleaned (physical cleaning process). After physical cleaning process, a substrate is heated and rinse liquid is supplied toward the first principal plane (rinsing process).SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a substrate processing method for processing a substrate, and a substrate processing apparatus for processing a substrate. Substrates to be processed include, 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, substrates for solar cells, and the like. [Background technology]

[0002] Techniques have been proposed for removing objects to be removed, such as particles adhering to the main surface of a substrate (see Patent Documents 1 and 2 below). Patent Document 1 discloses a substrate processing method in which a sulfuric acid and hydrogen-peroxide mixture (SPM) is supplied to a main surface of a substrate that has been subjected to chemical mechanical polishing (CMP) using a slurry (abrasive) containing cerium oxide, to remove residue of the slurry adhering to the main surface of the substrate. However, in order to reduce the environmental load, it is desired to reduce the amount of sulfuric acid used.

[0003] Patent Document 2 discloses a method for removing a target object on a substrate without using sulfuric acid. Specifically, the method discloses a method in which a solid-state polymer film is formed on the main surface of the substrate, and a physical force is applied to the polymer film by colliding droplets of a cleaning liquid discharged from a spray nozzle with the polymer film, thereby peeling the polymer film off from the main surface of the substrate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-037650 A [Patent Document 2] JP 2020-161525 A Summary of the Invention [Problem to be solved by the invention]

[0005] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide a substrate processing method and a substrate processing apparatus capable of efficiently removing objects to be removed while reducing the environmental load. [Means for solving the problem]

[0006] One embodiment of the present invention provides a substrate processing method for processing a substrate having a first main surface and a second main surface opposite to the first main surface, the substrate processing method including a gelling-agent-containing liquid supplying step of supplying a gelling-agent-containing liquid containing a gelling agent to the first main surface; a gelling step of cooling the substrate to change the gelling-agent-containing liquid on the first main surface into a gel; a physical cleaning step of spraying a cleaning liquid toward the first main surface in which the gel has been formed to clean the first main surface; and a rinsing step of supplying a rinsing liquid having a temperature equal to or higher than the melting point of the gelling agent to the first main surface after the physical cleaning step.

[0007] According to this method, a gelling agent-containing liquid containing a gelling agent is supplied to a first main surface of a substrate. Then, the substrate is cooled, and the gelling agent-containing liquid is cooled through the substrate and turns into a gel. Therefore, the gel can be brought into close contact with the object to be removed present on the first main surface of the substrate, and the object to be removed can be firmly held by the gel. By spraying the cleaning liquid toward the first main surface of the substrate, a physical force can be applied to the gel. As a result, the gel on the first main surface breaks up while holding the object to be removed, and is pulled away from the first main surface together with the object to be removed. The cleaning liquid supplied to the first main surface forms a liquid flow on the first main surface, pushing the broken up gel out of the first main surface.

[0008] Since a physical force is applied to the gel that is firmly holding the object to be removed, the gel is split, and the object to be removed is still held by the split gel. Therefore, the apparent size of the object to be removed held by the split gel is enlarged. Therefore, the object to be removed held by the gel is more likely to be subjected to a physical force from the liquid flow of the cleaning liquid than the object to be removed without the gel attached. Therefore, by supplying the cleaning liquid toward the first main surface on which the gel is formed, the object to be removed can be efficiently removed from the first main surface.

[0009] As described above, the target material can be removed from the substrate without using sulfuric acid, that is, while reducing the environmental load. Then, a rinse liquid having a temperature equal to or higher than the melting point of the gelling agent is supplied to the first main surface. Even if gel residue is present on the first main surface, the residue can be heated by the rinse liquid to be converted into a sol. This allows the gelling agent to be changed into a gelling agent-containing liquid. Therefore, the gelling agent-containing liquid formed by the solization can be dispersed in the rinse liquid, and the gelling agent-containing liquid can be discharged outside the substrate together with the rinse liquid. This makes it possible to prevent the gel from remaining on the first main surface.

[0010] In one embodiment of the present invention, the rinsing step includes a step of ejecting the rinsing liquid having a temperature equal to or higher than the melting point of the gelling agent from a rinsing liquid nozzle toward the first main surface. Therefore, without providing a separate member for heating the substrate, the gel residue can be converted into a sol by the rinsing liquid, and the gelling agent-containing liquid formed by the sol can be discharged outside the first main surface. This makes it possible to prevent the gel from remaining on the first main surface.

[0011] In one embodiment of the present invention, the rinsing step includes a second main surface heating step of heating the second main surface to a temperature equal to or higher than the melting point of the gelling agent. This can assist in solation of the gel residue on the first main surface. Furthermore, even if the temperature of the rinsing liquid supplied to the first main surface is lower than the melting point of the gelling agent, the rinsing liquid on the first main surface can be heated to a temperature equal to or higher than the melting point of the gelling agent via the substrate. This can solize the gel residue on the first main surface, and can prevent the gel from remaining on the first main surface.

[0012] In one embodiment of the present invention, the gelling step includes a second main surface cooling step of cooling the second main surface. Therefore, the gelling agent-containing liquid on the first main surface can be cooled via the substrate in contact with the gelling agent-containing liquid without contacting any member other than the substrate with the gelling agent-containing liquid. Therefore, the gelling agent-containing liquid can be efficiently cooled while preventing impurities from being mixed into the gelling agent-containing liquid.

[0013] In one embodiment of the present invention, cooling of the second principal surface is continued even during the physical cleaning step. Therefore, it is possible to suppress the gel on the first principal surface from becoming a sol during the physical cleaning step. Therefore, it is possible to suppress the removal target from falling off the gel before the removal target is discharged outside the first principal surface of the substrate together with the gel split by the physical cleaning step.

[0014] In one embodiment of the present invention, the temperature of the cleaning liquid sprayed toward the first principal surface in the physical cleaning step is lower than the melting point of the gelling agent, so that a temperature rise of the gel caused by contact between the cleaning liquid and the gel on the first principal surface can be suppressed, and therefore the gel on the first principal surface can be suppressed from becoming a sol. In one embodiment of the present invention, the physical cleaning step includes a droplet spraying step of spraying a plurality of droplets of the cleaning liquid from a spray nozzle toward the first main surface.

[0015] The cleaning liquid sprayed toward the first main surface applies a physical force to the gel on the first main surface when it collides with the gel on the first main surface. Therefore, when multiple droplets of the cleaning liquid are sprayed toward the first main surface, a physical force is applied to the gel on the first main surface each time a droplet collides with the gel on the first main surface. On the other hand, when a continuous stream of the cleaning liquid is sprayed toward the first main surface, a relatively large physical force is applied to the gel when the cleaning liquid first collides with the gel on the first main surface, but the physical force applied to the gel thereafter is relatively small.

[0016] Therefore, by spraying a plurality of droplets of the cleaning liquid toward the first main surface, a physical force can be applied to the gel on the first main surface more stably than by spraying a continuous flow of the cleaning liquid toward the first main surface, and the gel can be broken up in a short time and discharged outside the first main surface together with the object to be removed in a short time. In one embodiment of the present invention, the melting point of the gelling agent is higher than the freezing point of the gelling agent. Therefore, after the gel is formed by cooling the gelling agent-containing liquid, the gel can be prevented from immediately returning to the gelling agent-containing liquid due to an unintended temperature rise. In other words, the gel that has been formed can be prevented from unintended solation.

[0017] For example, the melting point of the gelling agent is 20°C or more and 30°C or less, and the freezing point of the gelling agent is 15°C or more and 25°C or less. It is particularly preferable that the freezing point of the gelling agent is room temperature (e.g., 25°C) or less. In this case, it is possible to suppress gelling of the gelling agent-containing liquid before it is cooled in the gelling step, i.e., before it is supplied to the first main surface, or immediately after it is supplied to the first main surface. Therefore, it is not necessary to heat the gelling agent-containing liquid in order to keep it at a temperature higher than room temperature before cooling the substrate, which makes it easier to handle the gelling agent-containing liquid.

[0018] In one embodiment of the invention, the gelling agent is gelatin, agar, or a mixture thereof, in which case the gel formed on the first major surface is hydrophilic. Therefore, when the first main surface is a hydrophobic surface, the degree of adhesion of the gel to the first main surface is lower than when the first main surface is a hydrophilic surface. Therefore, the gel can be easily separated from the first main surface by spraying a cleaning liquid onto the first main surface. A hydrophobic surface is a surface that is more hydrophobic (less hydrophilic) than a hydrophilic surface.

[0019] On the other hand, when the first main surface is a hydrophilic surface, the degree of adhesion of the gel to the first main surface is higher than when the first main surface is a hydrophobic surface. Therefore, there may be cases where the gel cannot be sufficiently separated from the first main surface by spraying a cleaning liquid onto the first main surface. Even in such cases, the gel can be converted into a sol by heating the substrate after the physical cleaning step, and the gelling agent-containing liquid formed by the solization can be discharged outside the first main surface together with the rinsing liquid. This makes it possible to suppress the gel from remaining on the first main surface. Therefore, regardless of whether the first main surface is a hydrophobic surface or a hydrophilic surface, the object to be removed can be efficiently removed from the first main surface.

[0020] In one embodiment of the present invention, the first main surface of the substrate is a flat surface formed by CMP using an abrasive. Therefore, polishing residues are attached to the first main surface. The polishing residues include the abrasive used in CMP and particles generated from the substrate by polishing. The polishing residue adhering to the first main surface is chemically bonded to the first main surface, and a relatively large physical force is required to remove the abrasive and the polishing residue from the first main surface. Furthermore, the particle size of the polishing residue is relatively small, for example, smaller than the boundary layer thickness of the cleaning liquid flowing over the first main surface. Specifically, the particle size of the polishing residue is 20 nm or less. The particle size is a convenient value equivalent to the diameter of the target object when it is assumed to be a perfect sphere.

[0021] The boundary layer thickness is a thickness that is strongly affected by the viscosity of the cleaning liquid flow, and the physical force applied by the cleaning liquid is greater at a position farther from the first main surface than the boundary layer thickness, and the physical force applied by the cleaning liquid is smaller at a position closer to the first main surface than the boundary layer thickness. Therefore, if a physical force is applied to the gel holding the polishing residue to break the gel and thereby increase the apparent size of the polishing residue, the physical force applied by the liquid flow of the cleaning liquid can be increased. Therefore, the polishing residue can be efficiently removed from the first main surface by the liquid flow of the cleaning liquid. When the particle size of the polishing residue is smaller than the boundary layer thickness of the cleaning liquid, it is particularly preferable to make the apparent size of the polishing residue larger than the boundary layer thickness.

[0022] Furthermore, if the first main surface is a flat surface formed by CMP, a large physical force can be applied to the first main surface without having to consider the collapse of the uneven pattern. Therefore, a sufficient physical force can be applied to the gel in the physical cleaning process. Therefore, the object to be removed can be removed more efficiently. In one embodiment of the present invention, the gelling step includes a gel film forming step of forming a gel film made of the gel and holding the object to be removed on the first main surface, and the physical cleaning step includes a gel film piece discharging step of splitting the gel film with the cleaning liquid to form gel film pieces that hold the object to be removed, and discharging the gel film pieces together with the cleaning liquid to outside the first main surface.

[0023] According to this method, the gel film is split by the physical force of the cleaning liquid, and film pieces that hold the object to be removed are formed. By holding the object to be removed in the film pieces, the apparent size of the object to be removed on the first main surface can be enlarged. Therefore, the object to be removed held in the film pieces is more likely to be subjected to physical forces from the liquid flow of the cleaning liquid than the object to be removed not held in the film pieces. Therefore, by supplying the cleaning liquid toward the first main surface on which the gel is formed, the object to be removed can be efficiently discharged from the first main surface to the outside of the first main surface of the substrate together with the cleaning liquid.

[0024] Then, the substrate is heated and a rinsing liquid is supplied to the first main surface, so that the gel film residue remaining on the first main surface after cleaning with the cleaning liquid is sol-ified and converted into a gelling agent-containing liquid. By sol-ifying the gel film residue, the gelling agent-containing liquid formed by the sol-ification can be dispersed in the rinsing liquid, and the gelling agent-containing liquid can be discharged together with the rinsing liquid outside the first main surface of the substrate. This makes it possible to prevent gel from remaining on the first main surface after the rinsing step.

[0025] In one embodiment of the present invention, the rinsing step includes a solation step of converting a gel film residue remaining on the first main surface after the physical cleaning step into a solation by heating. Another embodiment of the present invention provides a substrate processing method for processing a substrate having a first main surface and a second main surface opposite to the first main surface, the substrate processing method including: a gelling-agent-containing liquid supplying step of supplying a gelling-agent-containing liquid containing a gelling agent to the first main surface; a cooling fluid discharging step of discharging a cooling fluid having a temperature below the freezing point of the gelling agent from a cooling fluid nozzle toward the second main surface after the gelling-agent-containing liquid supplying step; a cleaning liquid spraying step of spraying a cleaning liquid toward the first main surface after the cooling fluid spraying step; and a rinsing liquid spraying step of spraying a rinsing liquid having a temperature above the melting point of the gelling agent from a rinsing liquid nozzle toward the first main surface after the cleaning liquid spraying step.

[0026] According to this method, a gelling agent-containing liquid containing a gelling agent is supplied to a first main surface of a substrate. A cooling fluid having a temperature equal to or lower than the freezing point of the gelling agent is discharged from a cooling fluid nozzle toward a second main surface of the substrate, thereby cooling the gelling agent-containing liquid through the substrate. This causes the gelling agent-containing liquid to change into a gel. Therefore, the gel can be brought into close contact with the object to be removed present on the first main surface of the substrate, and the object to be removed can be firmly held by the gel.

[0027] By spraying the cleaning liquid toward the first main surface of the substrate, a physical force can be applied to the gel. As a result, the gel on the first main surface of the substrate breaks up while holding the object to be removed, and is pulled away from the first main surface together with the object to be removed. The cleaning liquid supplied to the first main surface forms a liquid flow on the first main surface, pushing the broken up gel out of the first main surface. Since a physical force is applied to the gel that is firmly holding the object to be removed, the gel is split, and the object to be removed is still held by the split gel. Therefore, the apparent size of the object to be removed held by the split gel is enlarged. Therefore, the object to be removed held by the gel is more likely to be subjected to a physical force from the liquid flow of the cleaning liquid than the object to be removed without the gel attached. Therefore, by supplying the cleaning liquid toward the first main surface on which the gel is formed, the object to be removed can be efficiently removed from the first main surface.

[0028] As described above, the target material can be removed from the substrate without using sulfuric acid, that is, while reducing the environmental load. Then, by ejecting a rinse liquid having a temperature equal to or higher than the melting point of the gelling agent from a rinse liquid nozzle toward the first main surface, the gel residue remaining on the first main surface is heated to a temperature equal to or higher than the melting point of the gelling agent and converted into a sol. This allows the gelling agent to be changed into a gelling agent-containing liquid. Therefore, the gelling agent-containing liquid formed by the solization can be dispersed in the rinse liquid, and the gelling agent-containing liquid can be discharged outside the substrate together with the rinse liquid. This makes it possible to prevent the gel from remaining on the first main surface.

[0029] Yet another embodiment of the present invention provides a substrate processing apparatus for processing a substrate having a first main surface and a second main surface opposite to the first main surface, the substrate processing apparatus including: a gelling-agent-containing liquid nozzle that ejects a gelling-agent-containing liquid containing a gelling agent toward the first main surface; a cooling unit that cools the second main surface to a temperature below the freezing point of the gelling agent; a cleaning liquid nozzle that ejects a cleaning liquid toward the first main surface to clean the first main surface; and a rinsing liquid nozzle that ejects a rinsing liquid having a temperature above the melting point of the gelling agent toward the first main surface.

[0030] According to this device, a gelling agent-containing liquid containing a gelling agent is discharged from a gelling agent-containing liquid nozzle toward the first main surface of the substrate, whereby the gelling agent-containing liquid can be supplied to the first main surface. By cooling the substrate with the cooling unit, the gelling agent-containing liquid is cooled through the substrate, and the gelling agent-containing liquid changes into a gel. Therefore, the gel can be brought into close contact with the object to be removed present on the first main surface of the substrate, and the object to be removed can be firmly held by the gel.

[0031] By spraying the cleaning liquid toward the first main surface of the substrate, a physical force can be applied to the gel. As a result, the gel on the first main surface splits while holding the object to be removed, and the split gel is pulled away from the first main surface together with the object to be removed. The cleaning liquid supplied to the first main surface forms a liquid flow on the first main surface, pushing the split gel out of the first main surface. Since a physical force is applied to the gel that is firmly holding the object to be removed, the gel is split, and the object to be removed is still held by the split gel. Therefore, the apparent size of the object to be removed held by the split gel is enlarged. Therefore, the object to be removed held by the gel is more likely to be subjected to a physical force from the liquid flow of the cleaning liquid than the object to be removed without the gel attached. Therefore, by supplying the cleaning liquid toward the first main surface on which the gel is formed, the object to be removed can be efficiently removed from the first main surface.

[0032] As described above, the target material can be removed from the substrate without using sulfuric acid, that is, while reducing the environmental load. Then, by ejecting a rinse liquid having a temperature equal to or higher than the melting point of the gelling agent from a rinse liquid nozzle toward the first main surface, the gel residue remaining on the first main surface after cleaning with the cleaning liquid can be converted into a sole while supplying the rinse liquid to the first main surface. Therefore, the gelling agent-containing liquid formed by the sole conversion can be dispersed in the rinse liquid and discharged outside the substrate together with the rinse liquid. This makes it possible to prevent the gel from remaining on the first main surface.

[0033] In yet another embodiment of the present invention, the cooling unit cools the second main surface while the gelling-agent-containing liquid supplied from the gelling-agent-containing liquid nozzle onto the first main surface is present on the first main surface. The cleaning liquid nozzle sprays the cleaning liquid toward the first main surface while the gelling-agent-containing liquid on the first main surface is cooled by the cooling unit to form a gel on the first main surface. The rinsing liquid nozzle supplies the rinsing liquid toward the first main surface after the cleaning liquid is sprayed from the cleaning liquid nozzle onto the first main surface.

[0034] In yet another embodiment of the present invention, the gelling agent-containing liquid nozzle ejects the gelling agent-containing liquid, which contains the gelling agent having a melting point of 20°C or more and 30°C or less and a freezing point of 15°C or more and 25°C or less, toward the first main surface. In another embodiment of the present invention, the gelling agent-containing liquid nozzle ejects the gelling agent-containing liquid, which contains the gelling agent that is gelatin, agar, or a mixture thereof, toward the first main surface.

[0035] In another embodiment of the present invention, the cleaning liquid nozzle includes a spray nozzle that sprays a plurality of droplets of cleaning liquid toward the first main surface. In another embodiment of the present invention, the cleaning liquid nozzle sprays a cleaning liquid having a temperature equal to or lower than the freezing point of the gelling agent toward the first main surface. In another embodiment of the present invention, the cooling unit includes a cooling fluid nozzle configured to supply a cooling fluid having a temperature below the freezing point of the gelling agent to the second main surface. [Brief description of the drawings]

[0036] [Figure 1] FIG. 1 is a plan view for explaining an example of the configuration of a substrate processing apparatus according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic diagram for explaining the configuration of a processing unit provided in the substrate processing apparatus. [Diagram 3]FIG. 3 is a block diagram for explaining an electrical configuration of the substrate processing apparatus. [Figure 4] FIG. 4 is a cross-sectional view of a substrate which is an example of a processing target of the substrate processing apparatus. [Diagram 5] FIG. 5 is a cross-sectional view of a substrate which is another example of a processing target of the substrate processing apparatus. [Figure 6] FIG. 6 is a flow chart for explaining an example of substrate processing by the substrate processing apparatus. [Figure 7A] FIG. 7A is a schematic diagram for explaining the state of the substrate during the substrate processing. [Figure 7B] FIG. 7B is a schematic diagram for explaining the state of the substrate when the substrate processing is being performed. [Figure 7C] FIG. 7C is a schematic diagram for explaining the state of the substrate when the substrate processing is being performed. [Figure 7D] FIG. 7D is a schematic diagram for explaining the state of the substrate when the substrate processing is being performed. [Figure 8A] FIG. 8A is a schematic diagram for explaining the state in the vicinity of the first main surface of the substrate during the substrate processing. [Figure 8B] FIG. 8B is a schematic diagram for explaining the state near the first main surface of the substrate during the substrate processing. [Figure 8C] FIG. 8C is a schematic diagram for explaining the state near the first main surface of the substrate during the substrate processing. [Figure 8D] FIG. 8D is a schematic diagram for explaining the state near the first main surface of the substrate during the substrate processing. [Figure 8E] FIG. 8E is a schematic diagram for explaining the state near the first main surface of the substrate during the substrate processing. [Figure 8F] FIG. 8F is a schematic diagram for explaining the state near the first main surface of the substrate during the substrate processing. [Figure 8G] FIG. 8G is a schematic diagram for explaining the state near the first main surface of the substrate during the substrate processing. [Figure 9]FIG. 9 is a schematic view for explaining a first modified example of the substrate processing. [Figure 10] FIG. 10 is a schematic diagram for explaining a second modified example of the substrate processing. [Figure 11] FIG. 11 is a schematic diagram for explaining a modified example of the cleaning liquid nozzle. [Figure 12] FIG. 12 is a cross-sectional view illustrating a modified example of the cooling unit provided in the substrate processing apparatus. [Figure 13] FIG. 13 is a cross-sectional view illustrating a modified example of the heating unit provided in the substrate processing apparatus. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. <Configuration of the Substrate Processing Apparatus 1 according to the First Embodiment> FIG. 1 is a plan view for explaining an example of the configuration of a substrate processing apparatus 1 according to a first embodiment of the present invention. The substrate processing apparatus 1 is a single-wafer type apparatus that processes substrates W one by one. In this embodiment, the substrate W has a disk shape. The substrate W is a substrate W such as a silicon wafer, and has a pair of main surfaces (a first main surface W1 and a second main surface W2). The second main surface W2 is a main surface opposite to the first main surface W1.

[0038] The substrate processing apparatus 1 includes a plurality of processing units 2 for processing substrates W, a load port LP on which a carrier C is placed that accommodates a plurality of substrates W to be processed in the processing units 2, transport robots (a first transport robot IR and a second transport robot CR) that transport the substrates W between the load port LP and the processing units 2, and a controller 3 that controls each component included in the substrate processing apparatus 1.

[0039] The first transport robot IR transports the substrate W between the carrier C and the transport robot. The second transport robot CR transports the substrate W between the first transport robot IR and the processing unit 2. Each of the transport robots is, for example, a multi-joint arm robot including a pair of multi-joint arms AR and a pair of hands H respectively provided at the tips of the pair of multi-joint arms AR so as to be spaced apart from each other vertically.

[0040] The multiple processing units 2 form four processing towers TW arranged at four horizontally spaced positions. Each processing tower TW includes multiple processing units 2 stacked vertically. The four processing towers TW are arranged two on each side of the transport path TR extending from the load port LP toward the second transport robot CR. The processing unit 2 includes a chamber 4 and a processing cup 7 disposed in the chamber 4, and performs processing on the substrate W in the processing cup 7. The chamber 4 is formed with an entrance (not shown) through which the second transport robot CR loads and unloads the substrate W. The chamber 4 is provided with a shutter unit (not shown) that opens and closes the entrance.

[0041] FIG. 2 is a schematic diagram for explaining the configuration of the processing unit 2. As shown in FIG. The processing unit 2 further includes a spin chuck 5 that rotates the substrate W about a rotation axis A1 while holding the substrate W in a predetermined processing posture. The rotation axis A1 passes through the center of the substrate W and is perpendicular to each main surface of the substrate W held in the processing posture. The processing posture is, for example, the posture of the substrate W shown in FIG. 2, which is a horizontal posture in which the main surface of the substrate W is a horizontal plane. When the processing posture is the horizontal posture, the rotation axis A1 extends vertically. The spin chuck 5 is an example of a rotary holding member that rotates the substrate W about the rotation axis A1 while holding the substrate W in the processing posture.

[0042] The spin chuck 5 includes a spin base 21 having a horizontally extending circular disk shape, a plurality of chuck pins 20 that grip the substrate W above the spin base 21 and hold the substrate W in a holding position, a rotation shaft 22 whose upper end is connected to the spin base 21 and extends in the vertical direction, and a rotation drive mechanism 23 that rotates the rotation shaft 22 around its central axis (rotation axis A1). The multiple chuck pins 20 are arranged on the upper surface of the spin base 21 at intervals in the circumferential direction of the spin base 21. The rotation drive mechanism 23 is, for example, an actuator such as an electric motor. The rotation drive mechanism 23 rotates the rotation shaft 22 to rotate the spin base 21 and the multiple chuck pins 20 about the rotation axis A1. As a result, the substrate W is rotated together with the spin base 21 and the multiple chuck pins 20 about the rotation axis A1.

[0043] The multiple chuck pins 20 are movable between a closed position where they contact the peripheral edge of the substrate W to grip the substrate W, and an open position where they are retracted from the peripheral edge of the substrate W. The multiple chuck pins 20 are moved by an opening and closing mechanism (not shown). When the multiple chuck pins 20 are in the closed position, they grip the peripheral edge of the substrate W to horizontally hold the substrate W. The opening and closing mechanism includes, for example, a link mechanism and an actuator that applies a driving force to the link mechanism.

[0044] The processing cup 7 receives liquid splashed from the substrate W held on the spin chuck 5. The processing cup 7 includes a plurality of guards 30 (two in the example of FIG. 2) that receive liquid splashed outward from the substrate W held on the spin chuck 5, a plurality of cups 31 (two in the example of FIG. 2) that receive liquid guided downward by the guards 30, and a cylindrical outer wall member 32 that surrounds the guards 30 and the cups 31. The guards 30 are individually raised and lowered by a guard 30 lifting and lowering mechanism (not shown). The guard 30 lifting and lowering mechanism includes an actuator, such as an electric motor or an air cylinder, that drives each guard 30 to lift and lower.

[0045] The processing unit 2 further includes a gelling-agent-containing liquid nozzle 10 that ejects a continuous flow of gelling-agent-containing liquid toward the upper surface (upper main surface) of the substrate W held on the spin chuck 5, a cleaning liquid nozzle 11 that sprays a cleaning liquid toward the upper surface of the substrate W held on the spin chuck 5, and a rinsing liquid nozzle 12 that ejects a continuous flow of rinsing liquid toward the upper surface of the substrate W held on the spin chuck 5.

[0046] The gelling agent-containing liquid nozzle 10, the cleaning liquid nozzle 11, and the rinsing liquid nozzle 12 are all movable nozzles that are movable at least in the horizontal direction. The gelling agent-containing liquid nozzle 10, the cleaning liquid nozzle 11, and the rinsing liquid nozzle 12 are each moved in the horizontal direction by a plurality of nozzle movement mechanisms (a first nozzle movement mechanism 35, a second nozzle movement mechanism 36, and a third nozzle movement mechanism 37).

[0047] Each nozzle moving mechanism can move the corresponding nozzle between a central position and a retracted position. The central position is a position where the nozzle faces a central region of the upper surface of the substrate W. The central region of the upper surface of the substrate W is a region including the center of rotation (central portion) on the upper surface of the substrate W. The retracted position is a position where the nozzle does not face the upper surface of the substrate W, and is a position outside the processing cup 7.

[0048] Each nozzle moving mechanism includes an arm (first arm 35a, second arm 36a, and third arm 37a) that supports the corresponding nozzle, and an arm moving mechanism (first arm moving mechanism 35b, second arm moving mechanism 36b, and third arm moving mechanism 37c) that moves the corresponding arm in the horizontal direction. Each arm moving mechanism includes an actuator such as an electric motor or an air cylinder.

[0049] Unlike this embodiment, the gelling agent-containing liquid nozzle 10, the cleaning liquid nozzle 11, and the rinsing liquid nozzle 12 may be configured to move integrally by a common nozzle moving mechanism. Each moving nozzle may be a rotating nozzle that rotates about a predetermined rotation axis, or a linear nozzle that moves linearly in the extension direction of the corresponding arm. The gelling agent-containing liquid nozzle 10, the cleaning liquid nozzle 11, and the rinsing liquid nozzle 12 may be configured so as to be able to move in the vertical direction as well.

[0050] The gelling agent-containing liquid nozzle 10 has a single outlet 10a for discharging the gelling agent-containing liquid. The gelling agent-containing liquid discharged from the gelling agent-containing liquid nozzle 10 contains a gelling agent and a solvent that dissolves the gelling agent. The solvent contained in the gelling agent-containing liquid is, for example, water such as DIW (deionized water). However, the solvent is not limited to DIW. The solvent is not limited to DIW, but is a liquid containing at least one of DIW, carbonated water, electrolytic ionized water, diluted hydrochloric acid water (e.g., 1 ppm or more and 100 ppm or less), diluted ammonia water (e.g., 1 ppm or more and 100 ppm or less), and reduced water (hydrogen water).

[0051] The gelling agent is, for example, gelatin, agar, or a mixture thereof. The gelling agent-containing liquid is changed into a gel by being cooled below the freezing point of the gelling agent. The change of the gelling agent-containing liquid into a gel is called gelation. The gel is changed into the gelling agent-containing liquid by being heated above the melting point of the gelling agent. The change of the gel into the gelling agent-containing liquid is called solization. Therefore, the gelling agent-containing liquid is also called a sol. The temperature of the gelling agent-containing liquid discharged from the gelling agent-containing liquid nozzle 10 is higher than the freezing point of the gelling agent.

[0052] The melting point and freezing point of the gelling agent are usually different from each other, and the melting point of the gelling agent is higher than the freezing point of the gelling agent. Therefore, after the gel is formed by cooling the gelling agent-containing liquid, the gel can be prevented from immediately returning to the gelling agent-containing liquid due to an unintended temperature rise. In other words, the gel that has been formed can be prevented from unintended solation. The melting point of the gelling agent is, for example, 20°C or higher and 30°C or lower, and the freezing point of the gelling agent is, for example, 15°C or higher and 25°C or lower.

[0053] It is particularly preferable that the freezing point of the gelling agent is equal to or lower than room temperature (e.g., 25°C) in the clean room in which the substrate processing apparatus 1 is arranged. This can prevent the gelling agent-containing liquid from gelling before being discharged from the gelling agent-containing liquid nozzle 10 or immediately after being supplied to the first main surface W1. This makes it possible to avoid the gelling agent-containing liquid from gelling before being discharged from the gelling agent-containing liquid nozzle 10 or immediately after being supplied to the first main surface W1. This makes it easier to handle the gelling agent-containing liquid since there is no need to heat the gelling agent-containing liquid in order to keep the gelling agent-containing liquid supplied to the gelling agent-containing liquid nozzle 10 at a temperature higher than room temperature.

[0054] The melting point and freezing point of the gelling agent vary depending on the blending ratio (concentration) of the gelling agent in the etching gelling agent-containing liquid, the type of gelling agent, etc. For example, when the gelling agent-containing liquid contains only gelatin as the gelling agent, the melting point of the gelling agent is likely to be 20° C. or higher and 30° C. or lower, and the freezing point of the gelling agent is likely to be 15° C. or higher and 25° C. or lower. For example, if the gelling agent is gelatin and the concentration of gelatin in the gelling agent-containing liquid is 10%, the melting point of the gelling agent is 23° C. or higher and 30° C. or lower.

[0055] The melting point and freezing point of the gelling agent are not limited to the above ranges. When the gelling agent contains only agar, the melting point of the gelling agent may be 85°C or higher and 93°C or lower, and the freezing point of the gelling agent may be 33°C or higher and 45°C or lower. In the following, an example will be described in which a gelling agent-containing liquid is used in which the melting point of the gelling agent is 20° C. or more and 30° C. or less, and the freezing point of the gelling agent is 15° C. or more and 25° C. or less. In this case, the gelling agent-containing liquid can maintain a sol state at room temperature, and gels when cooled to less than 15° C. (for example, about 10° C.). The gel becomes a sol when heated to room temperature or a higher temperature (for example, about 40° C.).

[0056] The gelling-agent-containing liquid nozzle 10 is connected to a gelling-agent-containing liquid pipe 40 that guides the gelling-agent-containing liquid to the gelling-agent-containing liquid nozzle 10. The gelling-agent-containing liquid pipe 40 is provided with a gelling-agent-containing liquid valve 50A that opens and closes the gelling-agent-containing liquid flow path formed by the gelling-agent-containing liquid pipe 40, and a gelling-agent-containing liquid flow rate adjustment valve 50B that adjusts the flow rate of the gelling-agent-containing liquid in the gelling-agent-containing liquid flow path.

[0057] When the gelling-agent-containing liquid valve 50A is opened, the gelling-agent-containing liquid is discharged downward in a continuous flow from the discharge port 10a of the gelling-agent-containing liquid nozzle 10 at a flow rate that corresponds to the opening of the gelling-agent-containing liquid flow rate adjustment valve 50B. The cleaning liquid nozzle 11 is a spray nozzle that sprays multiple droplets of the cleaning liquid. The cleaning liquid nozzle 11 in this embodiment has multiple nozzles 11a, and sprays multiple droplets of the cleaning liquid (cleaning liquid droplets) from each nozzle 11a by application of a voltage. The cleaning liquid nozzle 11 sprays multiple cleaning liquid droplets toward the upper surface of the substrate W, thereby physically cleaning the upper surface of the substrate W. In more detail, if multiple cleaning liquid droplets are sprayed toward the upper surface of the substrate W when a gel is formed on the upper surface of the substrate W, a physical force can be applied to the gel on the upper surface of the substrate W, causing the gel to break up. The physical force is the impact (kinetic energy) that the cleaning liquid imparts to the gel on the substrate W.

[0058] The cleaning liquid sprayed from the cleaning liquid nozzle 11 is, for example, water such as DIW. The cleaning liquid is not limited to DIW, and may contain at least one of DIW, carbonated water, electrolytic ion water, diluted hydrochloric acid water (for example, 1 ppm or more and 100 ppm or less), diluted ammonia water (for example, 1 ppm or more and 100 ppm or less), and reduced water (hydrogen water).

[0059] The cleaning liquid nozzle 11 is connected to a cleaning liquid supply pipe 41 that guides the cleaning liquid to the cleaning liquid nozzle 11, and a cleaning liquid discharge pipe 42 that discharges the cleaning liquid from the cleaning liquid nozzle 11. The cleaning liquid supply pipe 41 is provided with a cleaning liquid supply valve 51A that opens and closes the cleaning liquid supply flow path formed by the cleaning liquid supply pipe 41, a cleaning liquid pump 51B that sends the cleaning liquid in the cleaning liquid supply flow path to the cleaning liquid nozzle 11, and a cleaning liquid cooler 51C that cools the cleaning liquid in the cleaning liquid supply flow path to a temperature lower than the melting point of the gelling agent. The cleaning liquid discharge pipe 42 is provided with a cleaning liquid discharge valve 52A that opens and closes the cleaning liquid discharge flow path formed by the cleaning liquid discharge pipe 42.

[0060] The cleaning liquid is cooled by the cleaning liquid cooler 51C, for example, to a temperature of 5° C. or more and less than 20° C. It is more preferable that the temperature of the cleaning liquid is 5° C. or more and 15° C. or less. When the cleaning liquid to be supplied to the cleaning liquid supply passage is cooled in advance to a temperature lower than the melting point of the gelling agent, the cleaning liquid cooler 51C is not necessary. The cleaning liquid pump 51B constantly sends out the cleaning liquid at a predetermined pressure (for example, 10 MPa or less) to the cleaning liquid nozzle 11. The cleaning liquid pump 51B can change the pressure of the cleaning liquid supplied to the cleaning liquid nozzle 11 to any pressure.

[0061] The cleaning liquid nozzle 11 has a built-in piezoelectric element 58 (piezo element). The piezoelectric element 58 is connected to a voltage application unit 59 via wiring. The voltage application unit 59 includes, for example, an inverter. The voltage application unit 59 applies an AC voltage to the piezoelectric element 58. When the AC voltage is applied to the piezoelectric element 58, the piezoelectric element 58 vibrates at a frequency corresponding to the frequency of the applied AC voltage. The voltage application unit 59 can change the frequency of the AC voltage applied to the piezoelectric element 58 to any frequency (for example, several hundred KHz to several MHz).

[0062] Since the cleaning liquid pump 51B is driven while the cleaning liquid supply valve 51A is open, the removal liquid is constantly supplied to the cleaning liquid nozzle 11 at high pressure. While the cleaning liquid discharge valve 52A is closed, the cleaning liquid supplied to the inside of the cleaning liquid nozzle 11 is sprayed from each nozzle 11a by the liquid pressure. Furthermore, when an AC voltage is applied to the piezoelectric element 58 while the cleaning liquid discharge valve 52A is closed, the vibration of the piezoelectric element 58 is imparted to the cleaning liquid in the cleaning liquid nozzle 11, and the cleaning liquid sprayed from each nozzle 11a is divided by this vibration. Therefore, when an AC voltage is applied to the piezoelectric element 58 while the cleaning liquid discharge valve 52A is closed, droplets of the cleaning liquid (cleaning liquid droplets 103) are sprayed from each nozzle 11a. As a result, a large number of cleaning liquid droplets 103 having a uniform particle size are sprayed simultaneously at a uniform speed.

[0063] The cleaning liquid supplied to the cleaning liquid nozzle 11 is cooled by the cleaning liquid cooler 51C to a temperature lower than the melting point of the gelling agent, so that the multiple cleaning liquid droplets 103 sprayed from the multiple nozzles 11a have a temperature lower than the melting point of the gelling agent (for example, a temperature greater than or equal to 5°C and less than 20°C). On the other hand, when the cleaning liquid discharge valve 52A is open, the cleaning liquid in the cleaning liquid nozzle 11 is discharged to the cleaning liquid discharge pipe 42. That is, when the cleaning liquid discharge valve 52A is open, the liquid pressure in the cleaning liquid nozzle 11 is not sufficiently increased, so the cleaning liquid in the cleaning liquid nozzle 11 is not sprayed from the nozzle 11a, which is a fine hole, and is discharged to the cleaning liquid discharge pipe 42. Therefore, the discharge of the cleaning liquid from the nozzle 11a is controlled by opening and closing the cleaning liquid discharge valve 52A.

[0064] The rinse liquid nozzle 12 has a single outlet 12a for discharging the rinse liquid. The rinse liquid discharged from the rinse liquid nozzle 12 is, for example, water such as DIW. The rinse liquid is not limited to DIW, but is a liquid containing at least one of DIW, carbonated water, electrolytic ion water, hydrochloric acid water with a diluted concentration (for example, 1 ppm or more and 100 ppm or less), ammonia water with a diluted concentration (for example, 1 ppm or more and 100 ppm or less), and reduced water (hydrogen water).

[0065] The solvent in the gelling agent-containing liquid, the cleaning liquid, and the rinsing liquid are all water-based liquids. If liquids having the same components (e.g., DIW) are used as the solvent in the gelling agent-containing liquid, the cleaning liquid, and the rinsing liquid, the number of tanks for storing the liquids to be supplied to the gelling agent-containing liquid nozzle 10, the cleaning liquid nozzle 11, and the rinsing liquid nozzle 12 can be reduced.

[0066] The rinse liquid nozzle 12 is connected to a rinse liquid pipe 43 that guides the rinse liquid to the rinse liquid nozzle 12. The rinse liquid pipe 43 is provided with a rinse liquid valve 53A that opens and closes a rinse liquid flow path formed by the rinse liquid pipe 43, a rinse liquid flow rate adjustment valve 53B that adjusts the flow rate of the rinse liquid in the rinse liquid flow path, and a rinse liquid heater 53C that heats the rinse liquid in the rinse liquid flow path to a temperature equal to or higher than the melting point of the gelling agent.

[0067] The rinse liquid is heated by the rinse liquid heater 53C to a temperature that is, for example, higher than 30° C. and lower than 50° C. It is more preferable that the temperature of the rinse liquid is 40° C. or higher and 50° C. or lower. When the rinse liquid supplied to the rinse liquid flow path is preheated to a temperature equal to or higher than the melting point of the gelling agent, the rinse liquid heater 53C is not necessary.

[0068] When the rinsing liquid valve 53A is opened, the rinsing liquid is discharged downward in a continuous flow from the discharge port 12a of the rinsing liquid nozzle 12 at a flow rate according to the opening degree of the rinsing liquid flow rate adjustment valve 53B. The processing unit 2 further includes a lower fluid nozzle 13 that supplies a fluid to the lower surface (lower main surface) of the substrate W held by the spin chuck 5. The lower fluid nozzle 13 is inserted into the internal space of the rotating shaft 22 and into a through-hole 21a that opens in the center of the upper surface of the spin base 21. The outlet 13a of the lower fluid nozzle 13 is exposed from the upper surface of the spin base 21. The outlet 13a of the lower fluid nozzle 13 faces a central region of the lower surface of the substrate W from below. The central region of the lower surface of the substrate W refers to a region of the lower surface of the substrate W that includes the center of rotation (central portion) of the substrate W.

[0069] The lower fluid nozzle 13 selectively supplies, as fluid, a cooling fluid having a temperature equal to or lower than the freezing point of the gelling agent and a heating fluid having a temperature equal to or higher than the melting point of the gelling agent to the lower surface of the substrate W. The cooling fluid has a temperature, for example, equal to or higher than 5° C. and lower than 15° C. The heating fluid has a temperature, for example, higher than 30° C. and lower than 50° C. The cooling fluid and the heating fluid are, for example, water such as DIW. In other words, the cooling fluid may be cold water and the heating fluid may be hot water. The cooling fluid and the heating fluid may be liquids other than water. The cooling fluid and the heating fluid do not need to be liquids and may be inert gases such as nitrogen gas and rare gases. The inert gas is a gas whose reactivity with the main surface of the substrate W is negligibly low.

[0070] By cooling the lower surface of the substrate W with a cooling fluid, the lower surface of the substrate W can be cooled to a temperature below the freezing point of the gelling agent. By continuing to cool the lower surface of the substrate W, the entire substrate W can be cooled to a temperature below the freezing point of the gelling agent. In order to quickly cool the substrate W, it is more preferable that the temperature of the cooling fluid is lower than the freezing point (for example, 5°C or higher and 10°C or lower). By heating the lower surface of the substrate W with a heating fluid, the lower surface of the substrate W can be heated to a temperature above the melting point of the gelling agent. By continuing to heat the lower surface of the substrate W, the entire substrate W can be heated to a temperature above the melting point of the gelling agent. In order to quickly heat the substrate W, it is more preferable that the temperature of the heating fluid is higher than the melting point (for example, 40°C or higher and 50°C or lower).

[0071] The lower fluid nozzle 13 is an example of a cooling fluid nozzle that ejects a cooling fluid having a temperature below the freezing point of the gelling agent toward the lower surface (second main surface W2) of the substrate W, and is an example of a heating fluid nozzle that ejects a heating fluid having a temperature above the melting point of the gelling agent toward the lower surface (second main surface W2) of the substrate W. The lower fluid nozzle 13 is an example of a cooling unit that cools the lower surface (second main surface W2) of the substrate W, and is an example of a heating unit that heats the lower surface (second main surface W2) of the substrate W.

[0072] The lower fluid nozzle 13 is connected to a fluid pipe 44 that guides a fluid to the lower fluid nozzle 13. A cooling fluid pipe 45 that supplies a cooling fluid to the fluid pipe 44 and a heating fluid pipe 46 that supplies a heating fluid to the fluid pipe 44 are connected to the fluid pipe 44. The fluid pipe 44 may be connected to the cooling fluid pipe 45 and the heating fluid pipe 46 via a mixing valve (not shown).

[0073] The fluid piping 44 is provided with a fluid valve 54 that opens and closes the flow path formed by the fluid piping 44. The cooling fluid piping 45 is provided with a cooling fluid valve 55A that opens and closes the cooling fluid flow path formed by the cooling fluid piping 45, and a cooling fluid flow rate adjustment valve 55B that adjusts the flow rate of the cooling fluid in the cooling fluid flow path. The heating fluid piping 46 is provided with a heating fluid valve 56A that opens and closes the heating fluid flow path formed by the heating fluid piping 46, and a heating fluid flow rate adjustment valve 56B that adjusts the flow rate of the heating fluid in the heating fluid flow path.

[0074] The cooling fluid pipe 45 is provided with a fluid cooler 55C that cools the fluid to a temperature below the freezing point of the gelling agent. As described above, the melting point of the gelling agent is higher than the freezing point of the gelling agent. Therefore, if the temperature is below the freezing point of the gelling agent, the temperature is lower than the melting point of the gelling agent. The heating fluid pipe 46 is provided with a fluid heater 56C that heats the fluid to a temperature above the melting point of the gelling agent.

[0075] If the fluid supplied to the cooling fluid passage is pre-cooled to a temperature below the freezing point of the gelling agent, the fluid cooler 55C is not required. If the fluid supplied to the heating fluid passage is pre-heated to a temperature above the melting point of the gelling agent, the fluid heater 56C is not required. 3 is a block diagram for explaining a configuration example regarding control of the substrate processing apparatus 1. The controller 3 includes a microcomputer, and controls the controlled objects included in the substrate processing apparatus 1 according to a predetermined control program.

[0076] Specifically, the controller 3 includes a processor 3A (CPU) and a memory 3B in which a control program is stored. The controller 3 is configured to execute various controls for substrate processing by the processor 3A executing the control program. In particular, the controller 3 is programmed to control the first transport robot IR, the second transport robot CR, the rotation drive mechanism 23, the first nozzle moving mechanism 35, the second nozzle moving mechanism 36, the third nozzle moving mechanism 37, the rinse liquid heater 53C, the fluid heater 56C, the cleaning liquid cooler 51C, the fluid cooler 55C, the cleaning liquid pump 51B, the voltage application unit 59, the gelling agent-containing liquid valve 50A, the gelling agent-containing liquid flow rate control valve 50B, the cleaning liquid supply valve 51A, the cleaning liquid discharge valve 52A, the rinse liquid valve 53A, the rinse liquid flow rate control valve 53B, the fluid valve 54, the cooling fluid valve 55A, the cooling fluid flow rate control valve 55B, the heating fluid valve 56A, the heating fluid flow rate control valve 56B, and the like.

[0077] The controller 3 controls the valves to control whether or not the corresponding nozzles discharge fluid and the discharge flow rate of the fluid from the corresponding nozzles. Each process shown in Fig. 6, which will be described later, is executed by the controller 3 controlling each member included in the substrate processing apparatus 1. In other words, the controller 3 is programmed to execute each process shown in Fig. 6, which will be described later.

[0078] <Configuration of the substrate to be processed> Next, the configuration of the substrate W used in the substrate processing apparatus 1 will be described. The first main surface W1 of the substrate W used in the substrate processing apparatus 1 is, for example, a flat surface. The first main surface W1 of the substrate W used in the substrate processing apparatus 1 is, for example, a surface exposing one or more of silicon (Si), silicon nitride (SiN), silicon oxide (SiO2), silicon germanium (SiGe), germanium (Ge), nitrogen-doped silicon carbide (SiCN), tungsten (W), titanium nitride (TiN), cobalt (Co), copper (Cu), ruthenium (Ru), and amorphous carbon (aC).

[0079] The first main surface W1 may be a hydrophobic surface or a hydrophilic surface. A hydrophobic surface is a surface that is more hydrophobic (less hydrophilic) than a hydrophilic surface. The contact angle of the DIW with respect to the hydrophobic surface is larger than the contact angle of the DIW with respect to the hydrophilic surface. The contact angle of the DIW with respect to the first main surface W1 depends on the components exposed from the first main surface W1 and the shape of the first main surface W1. If the components exposed from the first main surface W1 are highly hydrophobic, the contact angle will be large. If fine irregularities are formed on the first main surface W1, the contact angle will be large.

[0080] For example, when SiCN, TiN, Si, aC, Ru, or the like is exposed from the first main surface W1, the contact angle of the DIW with the first main surface W1 may be 40° or more. When Si or TiN is exposed from the first main surface W1, the contact angle of the first main surface W1 can be reduced to less than 40° by treating the first main surface W1 with a chemical solution such as an APM (ammonia-hydrogen peroxide mixture) solution that contains an oxidizer.

[0081] A typical example of the substrate W used in the substrate processing apparatus 1 is a substrate that has been subjected to CMP using an abrasive (slurry). The first main surface W1 is made flat by performing CMP. Fig. 4 is a cross-sectional view of a substrate W, which is an example of a processing target of the substrate processing apparatus 1. The substrate W shown in Fig. 4 is a substrate W after an element isolation layer is subjected to CMP using cerium oxide (CeO2) as an abrasive. The element isolation layer is an insulating layer for electrically isolating devices formed on the main surface of the substrate W from each other.

[0082] 4 includes a semiconductor layer 70, a first insulator layer 71 formed on the semiconductor layer 70, a plurality of trenches 72 formed across the semiconductor layer 70 and the first insulator layer 71, and a plurality of second insulator layers 73 respectively embedded in the plurality of trenches 72. The trenches 72 penetrate the first insulator layer 71. The trenches 72 have a bottom 72a defined by the semiconductor layer 70.

[0083] The semiconductor layer 70 is, for example, a polysilicon layer. The first insulator layer 71 is, for example, a silicon nitride layer (SiN layer), and the second insulator layer 73 is, for example, a silicon oxide layer (SiO2 layer). The second insulator layer 73 is an element isolation layer. The first insulator layer 71 and the second insulator layer 73 are exposed from the first main surface W1 of the substrate W shown in FIG. 4. Therefore, silicon nitride and silicon oxide are exposed from the first main surface W1 of the substrate W.

[0084] 4, polishing residues are attached to the first main surface W1 of the substrate W as removal targets 80. The polishing residues include cerium oxide, which is an abrasive, and particles generated when the first insulator layer 71 and the second insulator layer 73 are polished. Fig. 5 is a cross-sectional view of a substrate W, which is another example of a processing target of the substrate processing apparatus 1. The substrate W shown in Fig. 5 is a substrate W after a low dielectric constant layer (low-k layer) has been subjected to CMP using silicon oxide as an abrasive.

[0085] 5 includes an insulating layer 75, a plurality of trenches 76 formed in the insulating layer 75, and a metal layer 77 embedded in each of the plurality of trenches 76. The trenches 76 have a bottom 76a defined by the insulating layer. The insulator layer 75 is a low dielectric constant layer, for example, a nitrogen-doped silicon carbide layer (SiCN layer) having a dielectric constant lower than that of silicon oxide. The metal layer 77 is, for example, a copper layer (Cu layer). The insulator layer 75 and the metal layer 77 are exposed from the first main surface W1 of the substrate W shown in FIG. 5. Therefore, the SiCN layer and the Cu layer are exposed from the first main surface W1 of the substrate W.

[0086] 5, polishing residues are attached to the first main surface W1 of the substrate W as removal targets 80. The polishing residues include silicon oxide, which is an abrasive, and particles generated when the insulator layer and the metal layer 77 are polished. The polishing residues adhering to the first main surface W1 of the substrate W shown in FIG. 4 and the first main surface W1 of the substrate W shown in FIG. 5 are chemically bonded to the first main surface W1, and a relatively strong physical force must be applied to remove the abrasive and the polishing residues from the first main surface W1. Furthermore, the size of the polishing residues is relatively small, for example, smaller than the boundary layer thickness of the cleaning liquid flowing over the first main surface W1. The particle size of the polishing residues is specifically 20 nm or less.

[0087] The substrate W to be processed by the substrate processing apparatus 1 is not limited to the substrate W shown in Fig. 4 and the substrate W shown in Fig. 5. The substrate W does not need to be a substrate W that has been subjected to CMP, and the first main surface W1 does not necessarily need to be a flat surface. In addition, the first main surface W1 may be a flat surface formed by a method other than CMP. The second main surface W2 of the substrate W may have a similar configuration to the first main surface W1, or may have a different configuration from the first main surface W1.

[0088] <An example of substrate processing> Fig. 6 is a flow chart for explaining an example of substrate processing performed by the substrate processing apparatus 1. Fig. 6 mainly shows processing that is realized by the controller 3 executing a program. In substrate processing by the substrate processing apparatus 1, for example, as shown in FIG. 6, a substrate loading step (step S1), a gelling agent-containing liquid supply step (step S2), a gelling step (step S3), a physical cleaning step (step S4), a rinsing step (step S5), a spin drying step (step S6), and a substrate unloading step (step S7) are performed in this order.

[0089] Figures 7A to 7D are schematic diagrams for explaining the state of each step of the substrate processing. Details of the substrate processing will be explained below mainly with reference to Figures 2 and 6. Figures 7A to 7D will be referred to as necessary. First, an unprocessed substrate W is carried into the processing unit 2 from the carrier C by the second transport robot CR (see FIG. 1) and handed over to the spin chuck 5 (substrate carrying step: step S1). As a result, the substrate W is held horizontally by the spin chuck 5 (substrate holding step). In this substrate processing, the substrate W is held so that the first main surface W1 faces up. The substrate W continues to be held by the spin chuck 5 until the spin dry step (step S6) is completed. With the substrate W held by the spin chuck 5, the rotary drive mechanism 23 starts rotating the substrate W (substrate rotation step).

[0090] After the transport robot retreats to the outside of the processing unit 2, a gelling agent-containing liquid supplying step (step S2) of supplying a gelling agent-containing liquid onto the upper surface of the substrate W is performed. Specifically, the first nozzle movement mechanism 35 moves the gelling agent-containing liquid nozzle 10 to the processing position. With the gelling agent-containing liquid nozzle 10 positioned at the processing position, the gelling agent-containing liquid valve 50A is opened. As a result, as shown in FIG. 7A, a continuous flow of gelling agent-containing liquid is discharged (supplied) from the gelling agent-containing liquid nozzle 10 toward the upper surface of the substrate W (gelling agent-containing liquid discharge step, gelling agent-containing liquid supply step). The gelling agent-containing liquid discharged from the gelling agent-containing liquid nozzle 10 lands on the upper surface of the substrate W. The gelling agent-containing liquid that has landed on the upper surface of the substrate W spreads radially from the landing point toward the periphery of the upper surface of the substrate W.

[0091] In this substrate processing, the processing position of the gelling agent-containing liquid nozzle 10 is the central position. Therefore, the gelling agent-containing liquid lands in the central region of the upper surface of the substrate W. Unlike this embodiment, the gelling agent-containing liquid nozzle 10 may eject the gelling agent-containing liquid while moving horizontally along the upper surface of the substrate W. After the gelling agent-containing liquid supplying step (step S2), a gelling step (step S3) is performed in which the substrate W is cooled to gel the gelling agent-containing liquid on the upper surface of the substrate W.

[0092] Specifically, the gelling agent-containing liquid valve 50A is closed to stop the discharge of the gelling agent-containing liquid, and instead, the fluid valve 54 and the cooling fluid valve 55A are opened. As a result, as shown in Fig. 7B, a cooling fluid such as cold water is discharged (supplied) from the lower fluid nozzle 13 toward the lower surface of the substrate W (cooling fluid discharge step, cooling fluid supply step). After the gelling agent-containing liquid valve 50A is closed, the first nozzle moving mechanism 35 moves the gelling agent-containing liquid Nozzle 10 Move to the evacuation position.

[0093] The cooling fluid discharged from the lower fluid nozzle 13 lands (collides) on the central region of the lower surface of the substrate W. The cooling fluid spreads over the entire lower surface of the substrate W due to the action of centrifugal force. As a result, the substrate W is cooled from below (the second main surface W2 side) by the cooling fluid, and the gelling agent-containing liquid is cooled through the substrate W. That is, the gelling agent-containing liquid on the upper surface of the substrate W is cooled by the cooling of the lower surface (second main surface W2) of the substrate W by the cooling fluid (second main surface cooling step). The gelling agent-containing liquid on the upper surface of the substrate W gels due to cooling, and a gel film 81 covering almost the entire upper surface of the substrate W is formed on the upper surface of the substrate W (gelling step, gel film forming step).

[0094] By cooling the underside of the substrate W, the gelling agent-containing liquid on the substrate W can be cooled via the substrate W, without bringing any member other than the substrate W into contact with the gelling agent-containing liquid. Therefore, the gelling agent-containing liquid can be efficiently cooled while preventing impurities from being mixed into the gelling agent-containing liquid. The cooling fluid is cooled by the fluid cooler 55C to a temperature below the freezing point of the gelling agent. Therefore, by supplying the cooling fluid to the lower surface of the substrate W, the temperature of the gelling agent-containing liquid on the substrate W is reduced to a temperature below the freezing point of the gelling agent. This can promote gelation of the gelling agent-containing liquid. In this way, the second main surface W2 of the substrate W can be cooled by the simple method of supplying the cooling fluid from the lower fluid nozzle 13.

[0095] The gelling agent-containing liquid on the substrate W is discharged outside the upper surface of the substrate W by the action of centrifugal force caused by the rotation of the substrate W. As a result, the liquid film of the gelling agent-containing liquid on the upper surface of the substrate W is thinned (thinning process). By reducing the amount of the gelling agent-containing liquid on the substrate W, the temperature of the entire liquid film of the gelling agent-containing liquid is likely to decrease. In other words, gelation of the gelling agent-containing liquid is promoted.

[0096] After the gelation process (step S3), a physical cleaning process (step S4) is performed in which, while cooling the substrate W with the gel film 81 formed thereon, a cleaning liquid is sprayed toward the upper surface of the substrate W with the gel film 81 formed thereon to clean the upper surface of the substrate W. Specifically, the second nozzle moving mechanism 36 moves the cleaning liquid nozzle 11 to the processing position. With the cleaning liquid nozzle 11 in the processing position, the cleaning liquid discharge valve 52A is closed, and an AC voltage is applied to the piezoelectric element 58. As a result, as shown in Fig. 7C, a plurality of cleaning liquid droplets 103 are sprayed from the cleaning liquid nozzle 11 toward the upper surface of the substrate W (cleaning liquid spraying step, droplet spraying step). Then, the fluid valve 54 and the cooling fluid valve 55A are closed, and the supply of the cooling fluid to the lower surface of the substrate W is stopped.

[0097] A plurality of cleaning liquid droplets 103 ejected from the cleaning liquid nozzle 11 collide with the gel film 81 on the upper surface of the substrate W. As a result of the plurality of cleaning liquid droplets 103 colliding with the gel film 81, the gel film 81 is separated from the upper surface of the substrate W while being split. The cleaning liquid droplets 103 that collide with the upper surface of the substrate W form radial liquid flows (cleaning liquid flows 104) on the upper surface of the substrate W toward the periphery of the upper surface of the substrate W. Therefore, the cleaning liquid that has landed on the upper surface of the substrate W spreads from the landing point toward the periphery of the upper surface of the substrate W. The gel film 81 that has split and been detached from the upper surface of the substrate W is removed from the upper surface of the substrate W by the cleaning liquid flows 104. That is, the upper surface of the substrate W is cleaned by the physical force of the cleaning liquid droplets 103 (physical cleaning process).

[0098] In this substrate processing, the processing position of the cleaning liquid nozzle 11 is the central position. Therefore, the cleaning liquid lands in the central region of the upper surface of the substrate W. Unlike this embodiment, the cleaning liquid nozzle 11 may eject the cleaning liquid while moving horizontally along the upper surface of the substrate W. By spraying a plurality of cleaning liquid droplets 103 toward the upper surface of the substrate W, a physical force acts on the gel film 81 each time the cleaning liquid droplets 103 collide with the gel film 81. In contrast to this substrate processing, when a continuous flow of cleaning liquid is sprayed toward the upper surface of the substrate W, a relatively large physical force acts on the gel film 81 when the continuous flow of cleaning liquid first collides with the gel film 81, but the physical force acting on the gel film 81 thereafter is relatively small.

[0099] Therefore, by jetting a plurality of cleaning liquid droplets 103 toward the upper surface of the substrate W, a physical force can be applied to the gel film 81 more stably than in the case of jetting a continuous flow of the cleaning liquid toward the upper surface of the substrate W. As a result, the gel film 81 can be split in a short time, and the gel film 81 can be discharged outside the first main surface W1 together with the removal target 80 in a short time. The cleaning liquid is maintained at a temperature lower than the melting point of the gelling agent by cleaning liquid cooler 51C. This makes it possible to suppress a rise in temperature of gel film 81 caused by contact between the cleaning liquid and gel film 81. This makes it possible to suppress gel film 81 from becoming a sol.

[0100] After the physical cleaning step (step S4), a rinsing step (step S5) is performed in which the substrate W is heated to a temperature equal to or higher than the melting point of the gelling agent and a rinsing liquid is supplied toward the upper surface of the substrate W. Specifically, the cleaning liquid discharge valve 52A is opened, and the application of current to the piezoelectric element 58 is stopped. This stops the spraying of the cleaning liquid droplets 103 from the cleaning liquid nozzle 11. After the spraying of the cleaning liquid droplets 103 from the cleaning liquid nozzle 11 is stopped, the second nozzle movement mechanism 36 moves the cleaning liquid nozzle 11 to the retracted position.

[0101] Meanwhile, the third nozzle movement mechanism 37 moves the rinsing liquid nozzle 12 to the processing position. With the rinsing liquid nozzle 12 positioned at the processing position, the rinsing liquid valve 53A is opened. As a result, a continuous flow of rinsing liquid is discharged (supplied) from the rinsing liquid nozzle 12 toward the upper surface of the substrate W (rinsing liquid discharge step, rinsing liquid supply step), as shown in Fig. 7D. The rinsing liquid discharged from the rinsing liquid nozzle 12 lands on the upper surface of the substrate W. The rinsing liquid that has landed on the upper surface of the substrate W spreads radially from the landing point toward the periphery of the upper surface of the substrate W.

[0102] In this substrate processing, the processing position of the rinsing liquid nozzle 12 is the central position. Therefore, the rinsing liquid lands in a central region of the upper surface of the substrate W. Unlike this embodiment, the rinsing liquid nozzle 12 may eject the rinsing liquid while moving horizontally along the upper surface of the substrate W. Even after physical cleaning with a cleaning liquid, gel may remain on the upper surface of the substrate W. The gel that remains on the upper surface of the substrate W even after physical cleaning is called gel film residue. The gel film residue is heated by a rinsing liquid having a temperature equal to or higher than the melting point of the gelling agent, and is converted into a gelling agent-containing liquid (solization process). The rinsing liquid forms a liquid flow that spreads radially on the upper surface of the substrate W, so that the gelling agent-containing liquid formed by the solation can be dispersed in the rinsing liquid and discharged outside the upper surface of the substrate W together with the rinsing liquid. This makes it possible to prevent gel from remaining on the upper surface of the substrate W.

[0103] It is not necessary for all of the gel film residue on the substrate W to be converted into a sole by the rinsing liquid, and part of the gel film residue may be pushed out from the upper surface of the substrate W by the flow of the rinsing liquid. Next, a spin dry process (step S6) is performed in which the substrate W is rotated at high speed to dry the upper surface of the substrate W. Specifically, the rinsing liquid valve 53A is closed. This stops the supply of the rinsing liquid to the upper surface of the substrate W.

[0104] Then, the rotation drive mechanism 23 accelerates the rotation of the substrate W, rotating the substrate W at high speed (for example, 1500 rpm). As a result, a large centrifugal force acts on the fluids (rinse liquid, etc.) adhering to the substrate W, and these fluids are thrown off around the substrate W. After the spin dry step (step S6), the rotation drive mechanism 23 stops the rotation of the substrate W. Thereafter, the second transport robot CR enters the processing unit 2, receives the processed substrate W from the spin chuck 5, and unloads it from the processing unit 2 (substrate unloading step: step S7). The substrate W is handed over from the second transport robot CR to the first transport robot IR, and is stored in the carrier C by the first transport robot IR.

[0105] Next, an example of change in the state near the first main surface W1 during substrate processing will be described. Figures 8A to 8G are schematic views for explaining the state near the first main surface W1 of the substrate W during substrate processing. As shown in Fig. 8A, a removal target 80 is attached to the first main surface W1 of the substrate W transferred from the second transport robot CR to the spin chuck 5. As shown in Fig. 8B, the gelling-agent-containing liquid is supplied to the first main surface W1, so that the gelling-agent-containing liquid comes into contact with the removal target 80.

[0106] The gelling agent-containing liquid on the first main surface W1 is cooled and gelled, thereby forming a gel film 81 on the first main surface W1, as shown in FIG. 8C. In this substrate processing, gel film 81 is not placed on first main surface W1, but rather, the gelling agent-containing liquid is gelled on first main surface W1 in a state where the gelling agent-containing liquid is in contact with removal target 80, thereby forming gel film 81. Therefore, gel film 81 can be brought into close contact with removal target 80, and removal target 80 can be firmly held by gel film 81.

[0107] After the gel film 81 is formed, droplets of the cleaning liquid are directed toward the gel film 81 as shown in FIG. 8D. 103 The droplets are sprayed onto the gel film 81. 103 By colliding with the gel film 81, as shown in FIG. 8E, a physical force can be applied to the gel film 81 on the first main surface W1. The ejection of the plurality of cleaning liquid droplets 103 onto the first main surface W1 is performed while cooling the substrate W. Therefore, a physical force can be applied to the gel film 81 while suppressing the gel film 81 from becoming a sol.

[0108] The gel film 81 breaks up while holding the object 80 to be removed, forming gel film pieces 82, which are then detached (peeled off) from the first main surface W1 together with the object 80 to be removed. The cleaning liquid supplied to the first main surface W1 forms a cleaning liquid flow 104 on the first main surface W1, and discharges the gel film pieces 82 outside the first main surface W1 (gel film piece discharging step). As shown in FIG. 8F, the cleaning liquid flow 104 can either detach the gel film pieces 82 that have not been detached from the first main surface W1 from the first main surface W1, or sweep away the gel film pieces 82 that have been detached from the first main surface W1.

[0109] By applying a physical force from the cleaning liquid droplet 103 to the gel film 81 holding the removal target 80 to form a gel film piece 82, the apparent size of the removal target 80 on the first main surface W1 can be enlarged. Therefore, the removal target 80 held by the gel film piece 82 is more likely to be subjected to a physical force from the cleaning liquid flow 104 than the removal target 80 not covered with gel. Therefore, by supplying the cleaning liquid toward the first main surface W1 on which the gel film 81 has been formed, the removal target 80 can be efficiently removed from the first main surface W1.

[0110] Thereafter, the substrate W is heated and a rinsing liquid is supplied to the first main surface W1, whereby gel film residue 83 (see FIG. 8F) remaining on the first main surface W1 after cleaning with the cleaning liquid is sol-ified and changed into a gelling agent-containing liquid (sol-ification step). By sol-ifying the gel film residue 83, the gelling agent-containing liquid formed by the sol-ification can be dispersed in the rinsing liquid, and the gelling agent-containing liquid can be discharged together with the rinsing liquid to the outside of the first main surface W1 of the substrate W. This makes it possible to prevent gel from remaining on the first main surface W1, as shown in FIG. 8G.

[0111] Here, in recent years, with the miniaturization of semiconductor devices, the removal target 80 adhering to the first main surface W1 has also become smaller. The particle size of the removal target 80 may be smaller than the boundary layer thickness of the cleaning liquid flowing on the first main surface W1. The particle size of the removal target 80 is, for example, 20 nm or less. The boundary layer thickness is a thickness that is strongly affected by the viscosity of the flow of the cleaning liquid, and the physical force acting from the cleaning liquid is greater at a position farther from the first main surface W1 than the boundary layer thickness, and is smaller at a position closer to the first main surface W1 than the boundary layer thickness.

[0112] Therefore, by increasing the apparent size of the object to be removed 80 by the gel film pieces 82, it is possible to make the particle size of the object to be removed 80 larger than the boundary layer thickness of the cleaning liquid. By increasing the apparent size of the object to be removed 80 by the gel film pieces 82, it is possible to easily discharge the object to be removed 80 outside the first main surface W1 by the cleaning liquid flow 104. The gelling agent used in this substrate processing is gelatin, agar, or a mixture thereof. Therefore, the gel film 81 is hydrophilic. When the first main surface W1 is a hydrophobic surface, the degree of adhesion of the gel film 81 to the first main surface W1 is lower than when the first main surface W1 is a hydrophilic surface. Therefore, the gel can be easily separated from the first main surface W1 by spraying a cleaning liquid onto the first main surface W1.

[0113] On the other hand, when the first main surface W1 is a hydrophilic surface, the degree of adhesion of the gel to the first main surface W1 is higher than when the first main surface W1 is a hydrophobic surface. Therefore, there may be cases where the gel cannot be sufficiently peeled off from the first main surface W1 by spraying the cleaning liquid onto the first main surface W1. Even in such cases, the gel can be turned into a sol and discharged together with the rinsing liquid to the outside of the first main surface W1 by supplying a rinsing liquid to the first main surface W1 while heating the substrate W after the physical cleaning process. This makes it possible to suppress the gel from remaining on the first main surface W1. Therefore, regardless of whether the first main surface W1 is a hydrophobic surface or a hydrophilic surface, the removal target 80 can be efficiently removed from the first main surface W1.

[0114] In this substrate processing, water such as DIW is used as the solvent contained in the cooling fluid, the rinsing liquid, the cleaning liquid, and the gelling agent-containing liquid, and gelatin or the like is used as the gelling agent contained in the gelling agent-containing liquid. Therefore, the removal target 80 can be removed from the substrate W without using a chemical liquid that has a large environmental load, such as sulfuric acid. If the environmental load is smaller than that of sulfuric acid, the solvent contained in the cooling fluid, the rinsing liquid, the cleaning liquid, and the gelling agent-containing liquid may be a liquid other than water, or may be a mixture of an organic solvent and water.

[0115] Furthermore, in the case where the first main surface W1 of the substrate W has been subjected to CMP, i.e., where the substrate W is the substrate W shown in FIG. 4 or FIG. 5, the first main surface W1 is a flat surface and the grain size of the polishing residue as the object to be removed 80 is 20 nm or less, so that the effect of removing the object to be removed 80 by the above-mentioned substrate processing becomes significant. If the first main surface W1 is a flat surface, a large physical force can be applied to the first main surface W1 without having to consider the collapse of the concave-convex pattern. Therefore, a sufficient physical force can be applied to the gel in the physical cleaning process. Therefore, the removal target 80 can be removed more efficiently.

[0116] <Modifications of Substrate Processing> 9 is a schematic diagram for explaining a first modified example of the substrate processing. As in the first modified example of the substrate processing shown in FIG. 9, cooling of the lower surface of the substrate W by the cooling fluid may be continued even after spraying of the cleaning liquid onto the upper surface of the substrate W has started (cooling continuation step). Therefore, the gel film 81 is cooled not only by the cleaning liquid but also by the cooling fluid, so that the gel film 81 can be prevented from becoming a solubilized film, as compared to the case where the gel film 81 is cooled only by the cleaning liquid.

[0117] The cooling fluid has a temperature equal to or lower than the freezing point of the gelling agent, and therefore may have a lower temperature than the cleaning liquid, which has a temperature lower than the melting point of the gelling agent. Therefore, the cooling fluid may have a higher effect of suppressing the solation of the gel film 81 than the cleaning liquid. By continuing to cool the underside of the substrate W even during the physical cleaning step, it is possible to prevent the gel film 81 from becoming a sol during the physical cleaning step. Therefore, it is possible to prevent the removal target 80 from falling off the gel film pieces 82 before the removal target 80 is discharged outside the substrate W together with the gel film 81 that has been split by the physical cleaning step.

[0118] If the cooling fluid can sufficiently cool the gel film 81, the cleaning liquid may have a temperature higher than the melting point of the gelling agent, unlike the first modified example of the substrate processing. In this case, cooling of the cleaning liquid may be omitted, and the cleaning liquid cooler 51C (see FIG. 2) can be omitted from the substrate processing apparatus 1. Fig. 10 is a schematic diagram for explaining a second modified example of the substrate processing. As in the second modified example of the substrate processing shown in Fig. 10, while the rinsing liquid is being discharged from the rinsing liquid nozzle 12 in the rinsing step, the lower surface (second main surface W2) of the substrate W may be heated by a heating fluid (second main surface heating step).

[0119] Specifically, after the physical cleaning step, the heating fluid valve 56A is opened. As a result, the heating fluid is discharged (supplied) from the lower fluid nozzle 13 toward the lower surface of the substrate W (heating fluid discharge step, heating fluid supply step). The heating fluid discharged from the lower fluid nozzle 13 lands (collides) on the central region of the lower surface of the substrate W. The heating fluid spreads over the entire lower surface of the substrate W due to the action of centrifugal force. As a result, the substrate W is heated from below (the second main surface W2 side), and the gel film residue 83 is heated through the substrate W. The heating fluid can be used to assist in the solation of the gel film residue 83. In this way, the second main surface W2 of the substrate W can be heated by a simple method of supplying the heating fluid from the lower fluid nozzle 13.

[0120] In the second modified substrate processing method, the gel film residue 83 is heated by both the heating fluid and the rinsing liquid. Therefore, the gel film residue 83 can be efficiently converted into a sole. Both the rinsing liquid and the heating fluid have a temperature equal to or higher than the melting point of the gelling agent. Therefore, the rinsing liquid can increase the temperature of the gel film residue 83, and the conversion of the gel film residue 83 into a sole can be promoted more efficiently.

[0121] Unlike the second modified example of the substrate processing, a rinse liquid having a temperature lower than the melting point of the gelling agent may be discharged from the rinse liquid nozzle 12 toward the upper surface of the substrate W. Even in this case, the rinse liquid on the upper surface of the substrate W can be heated to a temperature equal to or higher than the melting point of the gelling agent by heating the substrate W with a heating fluid while the rinse liquid is present on the upper surface of the substrate W. By heating the rinse liquid on the upper surface of the substrate W with a heating fluid, it is possible to supply a rinse liquid having a temperature higher than the melting point of the gelling agent to the upper surface of the substrate W.

[0122] In this way, even if the temperature of the rinsing liquid is lower than the melting point of the gelling agent, the gel residue can be assisted in solation by heating the lower surface of the substrate W with the heating fluid, thereby making it possible to prevent gel from remaining on the upper surface of the substrate W. It should be noted that heating by a heating fluid is not performed in the substrate processing shown in Fig. 6. Therefore, when performing the substrate processing shown in Fig. 6, the heating fluid pipe 46, the heating fluid valve 56A, the heating fluid flow rate control valve 56B, the fluid heater 56C, etc. may be omitted from the substrate processing apparatus 1 shown in Fig. 2.

[0123] <Modifications of the Substrate Processing Apparatus 1> Fig. 11 is a schematic diagram for explaining a modified example of the cleaning liquid nozzle 11. As shown in Fig. 11, the cleaning liquid nozzle 11 may be a spray nozzle that forms cleaning liquid droplets 103 by mixing a gas with the cleaning liquid. The cleaning liquid nozzle 11 shown in Fig. 11 is an external mixing type two-fluid nozzle that causes a cleaning liquid and a gas to collide in the air (outside the nozzle) to generate cleaning liquid droplets 103. Unlike the cleaning liquid nozzle 11 shown in Fig. 11, the cleaning liquid and the gas may be mixed inside the nozzle.

[0124] The cleaning liquid nozzle 11 has a cleaning liquid outlet 90 that discharges a continuous flow of cleaning liquid, and a gas outlet 91 that discharges gas. The gas discharged from the gas outlet 91 is, for example, an inert gas such as nitrogen gas. The inert gas does not have to be nitrogen gas, and may be a rare gas such as argon. The gas discharged from the gas outlet 91 may be a gas other than an inert gas, or may be air.

[0125] The cleaning liquid outlet 90 outlets the cleaning liquid downward. The gas outlet 91 is annular and surrounds the cleaning liquid outlet 90, and outlets gas obliquely inward. The outlet trajectory of the gas from the gas outlet 91 intersects with the outlet trajectory of the cleaning liquid from the cleaning liquid outlet 90. Therefore, a liquid flow 92 of the cleaning liquid from the cleaning liquid outlet 90 collides with a gas flow 93 from the gas outlet 91. A plurality of cleaning liquid droplets 103 are formed by the collision of the liquid flow 92 and the gas flow 93. The plurality of cleaning liquid droplets 103 thus formed are supplied toward the upper surface of the substrate W.

[0126] The cleaning liquid nozzle 11 is connected to a cleaning liquid pipe 94 and a gas pipe 96. The cleaning liquid pipe 94 is provided with a cleaning liquid valve 95A for opening and closing the cleaning liquid flow path formed by the cleaning liquid pipe 94, a cleaning liquid flow rate adjustment valve 95B for adjusting the flow rate of the cleaning liquid in the cleaning liquid flow path, and a cleaning liquid cooler 95C for cooling the cleaning liquid to a temperature lower than the melting point of the gelling agent. The gas pipe 96 is provided with a gas valve 97A for opening and closing the gas flow path formed by the gas pipe 96, and a gas flow rate adjustment valve 97B for adjusting the flow rate of the gas in the gas flow path.

[0127] Also, unlike Figures 2 and 11, the cleaning liquid nozzle 11 may not be a spray nozzle. Specifically, the cleaning liquid nozzle 11 may be a high-pressure nozzle that sprays a continuous flow of cleaning liquid by pushing the cleaning liquid out of a narrow outlet using a pump. The high-pressure nozzle may be, for example, an inkjet nozzle or a slit nozzle, but is not limited to these. Also, the cleaning liquid nozzle 11 may be a bar-shaped nozzle extending in both directions (for example, horizontally) on the upper surface of the substrate W.

[0128] Fig. 12 is a cross-sectional view for explaining a modified example of the cooling unit provided in the substrate processing apparatus 1. As shown in Fig. 12, the lower surface of the substrate W may be cooled by a cooling plate 110 facing the substrate W from below. The processing unit 2 includes a cooling plate 110 and an elevation shaft 115 connected to the lower surface of the cooling plate 110 for raising and lowering the cooling plate 110. The cooling plate 110 has a cooling surface 110a having a circular shape in a plan view. The cooling surface 110a is slightly smaller than the substrate W. The cooling surface 110a is formed by, for example, the upper surface of the cooling plate 110.

[0129] The cooling plate 110 has, for example, a built-in cooling fluid pipe 111 that constitutes a cooling fluid flow path in the cooling plate 110. A cooling fluid supply pipe 112 that supplies cooling fluid to the built-in cooling fluid pipe 111 and a cooling fluid discharge pipe 113 (cooling fluid discharge flow path) that discharges the cooling fluid from the built-in cooling fluid pipe 111 are connected to the built-in cooling fluid pipe 111. A cooling fluid supply valve 114 that opens and closes the cooling fluid supply flow path constituted by the cooling fluid supply pipe 112 is provided to the cooling fluid supply pipe 112.

[0130] A lifting mechanism (not shown) including an actuator such as a motor is connected to the lifting shaft 115. The cooling plate 110 is raised and lowered by the lifting mechanism between a contact position in contact with the lower surface of the substrate W and a spaced position spaced apart from the lower surface of the substrate W. The lifting mechanism includes an actuator such as an electric motor. The cooling plate 110 has a temperature below the freezing point of the gelling agent, and can cool the substrate W to a temperature below the freezing point of the gelling agent. More specifically, the cooling fluid has a temperature below the freezing point of the gelling agent, and the substrate W can be cooled to a temperature below the freezing point of the gelling agent by bringing the cooling plate 110 into contact with the lower surface of the substrate W. If the temperature of the cooling fluid is sufficiently low, it is also possible to cool the substrate W to a temperature below the freezing point of the gelling agent without bringing the cooling plate 110 into contact with the lower surface of the substrate W.

[0131] The cooling plate 110 has a temperature, for example, equal to or higher than 5° C. and lower than 15° C. In order to quickly cool the substrate W, it is more preferable that the cooling plate 110 has a temperature even lower than the freezing point (for example, equal to or higher than 5° C. and lower than 10° C.). By cooling the substrate W from below with the cooling plate 110, the lower surface of the substrate W can be cooled with high uniformity over its entire area.

[0132] 12, the lower fluid nozzle 13 that ejects the heating fluid is exposed from the cooling surface 110a of the cooling plate 110. A heating fluid pipe 46 is connected to the lower fluid nozzle 13. Fig. 13 is a cross-sectional view for explaining a modified example of the heating unit provided in the substrate processing apparatus 1. As shown in Fig. 13, the lower surface of the substrate W may be heated by a hot plate 116 facing the substrate W from below.

[0133] The processing unit 2 includes a hot plate 116 and an elevation shaft 117 connected to the lower surface of the hot plate 116 for raising and lowering the hot plate 116. The hot plate 116 has a heating surface 116a that is circular in plan view. The heating surface 116a is slightly smaller than the substrate W. The heating surface 116a is formed by, for example, the upper surface of the hot plate 116. Hot plate 116 includes, for example, a built-in heater 118. Heater 118 is connected to power supply line 119, and power is supplied to heater 118 from a power supply unit (not shown) such as a power source via power supply line 119.

[0134] A lifting mechanism (not shown) including an actuator such as a motor is connected to the lifting shaft 117. The hot plate 116 is raised and lowered by the lifting mechanism between a contact position in contact with the lower surface of the substrate W and a spaced position spaced from the lower surface of the substrate W. The hot plate 116 can be raised and lowered between a contact position in contact with the lower surface of the substrate W and a spaced position spaced from the lower surface of the substrate W. The lifting mechanism includes an actuator such as an electric motor.

[0135] The hot plate 116 has a temperature equal to or higher than the melting point of the gelling agent, and can heat the substrate W to a temperature equal to or higher than the melting point of the gelling agent. In particular, the heater 118 is heated to a temperature equal to or higher than the melting point of the gelling agent, and the hot plate 116 is brought into contact with the lower surface of the substrate W, thereby heating the substrate W to a temperature equal to or higher than the melting point of the gelling agent. If the temperature of the heater 118 is sufficiently high, it is also possible to heat the substrate W to a temperature equal to or higher than the melting point of the gelling agent, even if the hot plate 116 is not brought into contact with the lower surface of the substrate W.

[0136] The hot plate 116 has a temperature that is, for example, higher than 30° C. and lower than 50° C. In order to heat the substrate W quickly, it is more preferable that the temperature of the hot plate 116 is even higher than the melting point (for example, higher than 40° C. and lower than 50° C.). By heating the substrate W from below with the hot plate 116, it is possible to heat the entire lower surface of the substrate W with high uniformity. In the example shown in FIG. 13, the lower fluid nozzle 13 that ejects the cooling fluid is exposed from the heating surface 116a of the hot plate 116.

[0137] Although not shown, a single plate can function as both the cooling plate 110 and the hot plate 116 if the plate is configured to have switchable temperatures. <Other embodiments> The present invention is not limited to the above-described embodiment, and can be embodied in other forms.

[0138] For example, in the above-described embodiment, the substrate processing is performed on the upper surface of the substrate W. However, the substrate processing may be performed on the lower surface of the substrate W. In that case, the substrate W is held by the spin chuck 5 such that, during the substrate processing, the first main surface W1 is the lower surface and the second main surface W2 is the upper surface. Furthermore, the substrate W does not necessarily have to be held in a horizontal position by the spin chuck 5; it may be held in a vertical position, or the main surface of the substrate W may be held in a position inclined relative to the horizontal direction.

[0139] In the above embodiment, the spin chuck 5 is a gripping type spin chuck that grips the peripheral edge of the substrate W with a plurality of chuck pins 20, but the spin chuck 5 is not limited to a gripping type spin chuck. For example, the spin chuck 5 may be a vacuum suction type spin chuck that suctions the substrate W to the spin base 21. In the above-described embodiment, the gel residue is heated in the rinsing step by at least one of a heating fluid and the hot plate 116. However, the gel residue may be heated in the rinsing step by increasing the temperature of the internal space of the chamber 4, or by using a heater facing the first main surface W1 of the substrate W.

[0140] In the above-described embodiment, the gelling agent-containing liquid is cooled in the gelling step by at least one of a cooling fluid and the cooling plate 110. However, the gelling agent-containing liquid in the gelling step may be cooled by lowering the temperature of the internal space of the chamber 4, or may be cooled by using a cooler facing the first main surface W1 of the substrate W.

[0141] The cleaning liquid supplied to the cleaning liquid nozzle 11 may be cooled to a temperature equal to or lower than the freezing point of the gelling agent by a cleaning liquid cooler 51C. In this case, the cleaning liquid droplets 103 jetted from the jet ports 11a have a temperature equal to or lower than the freezing point of the gelling agent (for example, a temperature equal to or higher than 5°C and lower than 15°C). Furthermore, the mechanism by which the gel film 81 is removed from the first main surface W1 of the substrate W is not limited to the mechanism shown in Figures 8A to 8G. As long as the gel film 81 is removed from the first main surface W1 of the substrate W by a physical force applied by the spray of the cleaning liquid and the cleaning liquid flow 104, the mechanism by which the gel film 81 is removed may be different from that shown in Figures 8A to 8G.

[0142] In addition, in the above-described embodiment, some of the pipes, pumps, valves, actuators, etc. are omitted from the illustration, but this does not mean that these components do not exist, and in reality, these components are provided in appropriate positions. In the above embodiment, expressions such as "along", "horizontal", and "vertical" are used, but they do not necessarily have to be "along", "horizontal", and "vertical" strictly. In other words, these expressions allow for deviations in manufacturing precision, installation precision, and the like.

[0143] Furthermore, although each component may be shown diagrammatically as a block, the shape, size, and positional relationship of each block do not represent the shape, size, and positional relationship of each component. In addition, various modifications can be made within the scope of the claims. [Explanation of symbols]

[0144] 1: Substrate processing equipment 10: Nozzle containing gelling agent 11: Cleaning solution nozzle (spray nozzle) 12: Rinse liquid nozzle 13: Lower fluid nozzle (cooling fluid nozzle, cooling unit) 80: Object to be removed 81: Gel film 82: Gel membrane piece 83: Gel film residue 110: Cooling plate (cooling unit) W: Substrate W1: First main surface W2: Second main surface

Claims

1. 1. A substrate processing method for processing a substrate having a first main surface and a second main surface opposite to the first main surface, comprising: a gelling agent-containing liquid supplying step of supplying a gelling agent-containing liquid to the first main surface; a gelling step of cooling the substrate to change the gelling agent-containing liquid on the first main surface into a gel; a physical cleaning step of spraying a cleaning liquid having a temperature lower than the melting point of the gelling agent toward the first main surface on which the gel has been formed, to clean the first main surface; a rinsing step of supplying a rinsing liquid having a temperature equal to or higher than a melting point of the gelling agent to the first main surface after the physical cleaning step.

2. 2. The substrate processing method according to claim 1, wherein the rinsing step includes the step of ejecting the rinsing liquid, which has a temperature equal to or higher than a melting point of the gelling agent, from a rinsing liquid nozzle toward the first main surface.

3. 3. The substrate processing method according to claim 1, wherein the rinsing step includes a second main surface heating step of heating the second main surface to a temperature equal to or higher than a melting point of the gelling agent.

4. 4. The substrate processing method according to claim 1, wherein the gelling step includes a second main surface cooling step of cooling the second main surface.

5. The substrate processing method according to claim 4 , wherein cooling of the second main surface is continued even during the physical cleaning step.

6. 6. The substrate processing method according to claim 1, wherein the physical cleaning step includes a droplet spraying step of spraying a plurality of droplets of the cleaning liquid from a spray nozzle toward the first main surface.

7. The substrate processing method according to claim 1, wherein the gelling agent has a melting point higher than a solidifying point of the gelling agent.

8. 8. The substrate processing method according to claim 7, wherein the gelling agent has a melting point of 20° C. or more and 30° C. or less, and a freezing point of 15° C. or more and 25° C. or less.

9. The method for processing a substrate according to any one of claims 1 to 8, wherein the gelling agent is gelatin, agar, or a mixture thereof.

10. 10. The substrate processing method according to claim 1, wherein the first main surface of the substrate is a flat surface formed by chemical mechanical polishing using an abrasive.

11. the gelling step includes a gel film forming step of forming a gel film that is made of the gel and that holds the object to be removed on the first main surface, The substrate processing method according to any one of claims 1 to 10, wherein the physical cleaning step includes a gel film piece discharge step of splitting the gel film with the cleaning liquid to form gel film pieces that hold the object to be removed, and discharging the gel film pieces together with the cleaning liquid outside the first main surface.

12. The substrate processing method according to any one of claims 1 to 11, wherein the rinsing step includes a solation step of converting a gel film residue remaining on the first main surface into a sole by heating after the physical cleaning step.

13. 1. A substrate processing method for processing a substrate having a first main surface and a second main surface opposite to the first main surface, comprising: a gelling agent-containing liquid supplying step of supplying a gelling agent-containing liquid to the first main surface; a cooling fluid ejection step of ejecting a cooling fluid having a temperature equal to or lower than the freezing point of the gelling agent from a cooling fluid nozzle toward the second main surface after the gelling agent-containing liquid supply step; a cleaning liquid spraying step of spraying a cleaning liquid toward the first main surface after the cooling fluid spraying step; the rinse liquid ejection step of ejecting a rinse liquid having a temperature equal to or higher than the melting point of the gelling agent from a rinse liquid nozzle toward the first main surface after the cleaning liquid ejection step.

14. 1. A substrate processing apparatus for processing a substrate having a first main surface and a second main surface opposite to the first main surface, a gelling agent-containing liquid nozzle that ejects a gelling agent-containing liquid toward the first main surface; a cooling unit that cools the second main surface to a temperature equal to or lower than the freezing point of the gelling agent; a cleaning liquid nozzle configured to spray, toward the first main surface, a cleaning liquid having a temperature lower than a melting point of the gelling agent and configured to clean the first main surface; a rinse liquid nozzle configured to discharge a rinse liquid having a temperature equal to or higher than a melting point of the gelling agent toward the first main surface.

15. the cooling unit cools the second main surface while the gelling-agent-containing liquid supplied from the gelling-agent-containing liquid nozzle onto the first main surface is present on the first main surface, the cleaning liquid nozzle sprays the cleaning liquid toward the first main surface in a state in which the gelling agent-containing liquid on the first main surface is cooled by the cooling unit to form a gel on the first main surface; The substrate processing apparatus according to claim 14 , wherein the rinsing liquid nozzle supplies the rinsing liquid toward the first main surface after the cleaning liquid is sprayed from the cleaning liquid nozzle toward the first main surface.

16. 16. The substrate processing apparatus according to claim 14, wherein the gelling agent-containing liquid nozzle ejects the gelling agent-containing liquid, the gelling agent having a melting point of 20° C. or more and 30° C. or less and a freezing point of 15° C. or more and 25° C. or less, toward the first main surface.

17. The substrate processing apparatus according to any one of claims 14 to 16, wherein the gelling-agent-containing liquid nozzle ejects the gelling-agent-containing liquid, which contains the gelling agent that is gelatin, agar, or a mixture thereof, toward the first main surface.

18. The substrate processing apparatus according to any one of claims 14 to 17, wherein the cleaning liquid nozzle includes a spray nozzle that sprays a plurality of droplets of the cleaning liquid toward the first main surface.

19. The substrate processing apparatus according to any one of claims 14 to 18, wherein the cooling unit includes a cooling fluid nozzle that supplies a cooling fluid having a temperature equal to or lower than a freezing point of the gelling agent to the second main surface.

Images