JP7603517B2 - Substrate processing method and substrate processing apparatus - Google Patents

Description

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.

The following Patent Document 1 discloses a substrate processing method that achieves a desired etching amount by repeating a process of supplying an oxidizing fluid such as hydrogen peroxide solution (H ₂ O ₂ water) to a substrate to form a metal oxide layer, and a process of supplying an etching solution such as dilute hydrofluoric acid (DHF) to the substrate to remove the metal oxide layer.

JP 2020-155615 A

In the substrate processing of Patent Document 1, the metal oxide layer is etched by repeatedly forming and removing the metal oxide layer, so that the metal oxide layer can be etched with greater precision than when a large amount of the metal oxide layer is removed at once.
However, in the substrate processing of Patent Document 1, a continuous flow of dilute hydrofluoric acid and hydrogen peroxide solution is used for forming and removing the metal oxide layer, respectively, which requires the use of a large amount of chemicals such as dilute hydrofluoric acid and hydrogen peroxide solution in the substrate processing, which poses an environmental load problem.

Therefore, one object of the present invention is to provide a substrate processing method and a substrate processing apparatus that can reduce the amount of material used in etching a substrate.

One embodiment of the present invention provides a substrate processing method including a substrate preparation step of preparing a substrate having a main surface on which an oxide layer is exposed, a polymer film formation step of forming a polymer film containing an acidic polymer on the main surface of the substrate, a processing fluid supply step of supplying a processing fluid containing at least one of a mist of a processing liquid having affinity for the acidic polymer and a vapor of the processing liquid to the polymer film formed on the main surface of the substrate, and a rinsing step of supplying a rinsing liquid toward the main surface of the substrate after the processing fluid supply step.

According to this method, a polymer film is formed on the main surface of the substrate. Therefore, the substrate is etched and the oxide layer is removed from the substrate. At this time, a processing fluid containing at least one of a mist of the processing fluid and a vapor of the processing fluid is supplied to the polymer film. When the polymer film comes into contact with the processing fluid, minute droplets of the processing fluid adhere to the surface of the polymer film. Therefore, the processing fluid can be appropriately supplied to the polymer film while maintaining the polymer film on the main surface of the substrate. Since the processing fluid has an affinity for the acidic polymer, the processing fluid penetrates into the inside of the polymer film. This can promote the release of protons (hydrogen ions) from the acidic polymer. In other words, the etching of the substrate can be promoted. After that, the main surface of the substrate is washed with a rinse liquid to remove the polymer film from the main surface of the substrate, and the etching of the substrate can be stopped.

The polymer film used to etch the substrate contains an acidic polymer and therefore has a higher viscosity than liquids such as hydrofluoric acid. As a result, the polymer film is likely to remain on the main surface of the substrate. This means that there is no need to continuously supply the acidic polymer to the main surface of the substrate throughout the entire period during which the substrate is etched. In other words, at least after the polymer film is formed, there is no need to additionally supply the acidic polymer to the main surface of the substrate. This reduces the environmental impact.

In one embodiment of the present invention, the substrate preparation step includes an oxide layer formation step of oxidizing a surface layer portion of the main surface of the substrate to form an oxide layer.
According to this method, a substrate having an oxide layer formed on the surface layer portion of a main surface of the substrate is prepared by oxidizing the surface layer portion of the main surface of the substrate. Therefore, substrate processing can be started using a substrate having no oxide layer formed on the surface layer portion of the main surface.

The oxide layer can be formed by, for example, a wet oxidation process or a dry oxidation process. The wet oxidation process is, for example, a process in which a liquid oxidizing agent is supplied to the main surface of the substrate. The dry oxidation process is, for example, a process in which an oxide layer is formed by at least one of light irradiation, heating, and supply of a gaseous oxidizing agent.
In one embodiment of the present invention, the substrate processing method further includes a reforming step of oxidizing a surface layer of the main surface of the substrate to form an oxide layer after the rinsing step, and the reforming step, the polymer film forming step, the processing fluid supplying step, and the rinsing step are each performed at least once in this order after the rinsing step.

According to this method, the formation and removal of the oxide layer are alternately repeated, so that the substrate can be etched with high precision.
In one embodiment of the present invention, the polymer film formed in the polymer film forming step further contains an alkaline component. The substrate processing method further includes a polymer film heating step of heating the polymer film at the start of the processing fluid supplying step.

According to this method, the polymer film contains an alkaline component along with the acidic polymer. Therefore, after the polymer film is formed, the acidic polymer is neutralized by the alkaline component and is almost inactivated until the polymer film is heated. Therefore, after the polymer film is formed, removal of the oxide layer hardly starts until the polymer film is heated. By heating the polymer film to evaporate the alkaline component, the acidic polymer in the polymer film regains its activity. Therefore, it is easy to control the timing of the start of etching of the substrate.

In one embodiment of the present invention, the substrate processing method further includes a polymer-containing liquid supplying step of supplying a polymer-containing liquid containing at least a solvent and the acidic polymer to the main surface of the substrate, and the polymer film forming step includes a step of forming the polymer film by evaporating at least a part of the solvent in the polymer-containing liquid on the main surface of the substrate.
According to this method, a polymer film can be formed by evaporating the solvent from the polymer-containing liquid supplied to the substrate. Therefore, the concentration (density) of the acidic polymer in the polymer film can be increased by the evaporation of the solvent. Therefore, the substrate can be quickly etched by the high-concentration (high-density) acidic polymer.

In one embodiment of the present invention, the solvent is a liquid that is miscible with the processing liquid.
Since the polymer film is formed by evaporating at least a part of the solvent from the polymer-containing liquid, the solvent may remain in the polymer film. If the solvent is a liquid that is miscible with the processing liquid, the processing liquid that adheres to the polymer film when the polymer film comes into contact with the processing fluid mixes with the solvent remaining in the polymer film. Therefore, the processing liquid easily penetrates into the inside of the polymer film. This can promote etching of the substrate.

In one embodiment of the present invention, the treatment liquid is water. If the humidity of the treatment fluid is higher than 50% and not higher than 100%, water in a liquid state can be appropriately supplied to the polymer membrane.
It is more preferable that the humidity of the treatment fluid is 80% or more and 100% or less. If the humidity of the treatment fluid is 80% or more and 100% or less, water in a liquid state can be sufficiently supplied to the polymer membrane.

It is more preferable that the humidity of the treatment fluid is 85% or more and 95% or less. If the humidity of the treatment fluid is 85% or more and 95% or less, it is easy to control the amount of liquid water supplied to the polymer membrane while supplying a sufficient amount of liquid water to the polymer membrane.
In one embodiment of the present invention, the substrate processing method further includes a step of arranging a facing member having a facing surface facing the main surface of the substrate and a discharge port opening in the facing surface and discharging the processing fluid, and the processing fluid supply step includes a step of supplying the processing fluid to a space between the facing surface and the main surface of the substrate by discharging the processing fluid from the discharge port.

According to this method, the processing fluid is discharged from a discharge port provided in the facing member, and therefore the atmosphere in the space between the facing surface and the main surface of the substrate can be replaced with the processing fluid more quickly than in a configuration in which the entire space in which the substrate is placed is replaced with the processing fluid.
In one embodiment of the present invention, the processing fluid supplying step includes a step of moving the processing fluid nozzle along the main surface of the substrate while ejecting the processing fluid from the processing fluid nozzle toward a space on the main surface of the substrate that is in contact with the polymer film.

According to this method, the processing fluid nozzle ejects the processing fluid toward the space in contact with the polymer film on the main surface of the substrate while moving along the main surface of the substrate, and therefore, the processing fluid can be supplied quickly to the entire polymer film on the main surface of the substrate, compared to the case where the processing fluid is supplied toward only a part of the space in contact with the main surface of the substrate.
Another embodiment of the present invention provides a substrate processing apparatus including: a polymer film forming unit that forms a polymer film containing an acidic polymer on a main surface of a substrate; a processing fluid supply unit that supplies a processing fluid containing at least one of a mist of a processing liquid having affinity for the acidic polymer and vapor of the processing liquid toward the main surface of the substrate; and a rinsing liquid supply unit that supplies a rinsing liquid toward the main surface of the substrate.

According to this configuration, the polymer film can be formed on the main surface of the substrate by the polymer film forming unit. By forming the polymer film on the main surface of the substrate, the substrate is etched and the oxide layer is removed from the substrate.
In addition, in a state where a polymer film is formed on the main surface of the substrate, a processing fluid containing at least one of a mist and a vapor of the processing fluid can be supplied from a processing fluid supply unit toward the main surface of the substrate. When the polymer film comes into contact with the processing fluid, minute droplets of the processing fluid adhere to the surface of the polymer film. Therefore, the processing fluid can be appropriately supplied to the polymer film while maintaining the polymer film on the main surface of the substrate. Since the processing fluid has an affinity for the acidic polymer, the processing fluid penetrates into the inside of the polymer film. This can promote the release of protons (hydrogen ions) from the acidic polymer. That is, etching of the substrate can be promoted.

After the substrate is etched by the polymer film, a rinse liquid is supplied from the rinse liquid supply unit toward the main surface of the substrate, whereby the main surface of the substrate is cleaned and the polymer film is removed from the main surface of the substrate. Therefore, etching of the substrate can be started by the formation of the polymer film, and etching of the substrate can be stopped by removing the polymer film from the main surface of the substrate.
Therefore, the amount of etching of the substrate can be adjusted by forming and removing the polymer film, so that the substrate can be etched satisfactorily.

The polymer film used to etch the substrate contains an acidic polymer and therefore has a higher viscosity than liquids such as hydrofluoric acid. As a result, the polymer film is likely to remain on the main surface of the substrate. This means that there is no need to continuously supply the acidic polymer to the main surface of the substrate throughout the entire period during which the substrate is etched. In other words, at least after the polymer film is formed, there is no need to additionally supply the acidic polymer to the main surface of the substrate. This reduces the environmental impact.

In another embodiment of the present invention, the substrate processing apparatus further includes a substrate rotation unit that rotates the substrate about a rotation axis that passes through the center of the main surface of the substrate. The polymer film forming unit includes a polymer-containing liquid nozzle that ejects toward the main surface of the substrate a polymer-containing liquid that contains at least a solvent and the acidic polymer and forms the polymer film by evaporating the solvent.

According to this configuration, the substrate can be rotated by the substrate rotation unit while the polymer-containing liquid is being discharged from the polymer-containing liquid nozzle to supply the polymer-containing liquid to the main surface of the substrate, or after the polymer-containing liquid is supplied to the main surface of the substrate. This allows the polymer-containing liquid to be spread over almost the entire main surface of the substrate, while at the same time promoting evaporation of the solvent from the polymer-containing liquid to form a polymer film. Therefore, the concentration (density) of the acidic polymer in the polymer film can be increased by the evaporation of the solvent. Therefore, the substrate can be quickly etched by the high-concentration (high-density) acidic polymer.

In another embodiment of the invention, the solvent is a liquid that is miscible with the processing liquid.
Since the polymer film is formed by evaporating at least a part of the solvent from the polymer-containing liquid, the solvent may remain in the polymer film. If the solvent is a liquid that is miscible with the processing liquid, the processing liquid that adheres to the polymer film when the polymer film comes into contact with the processing fluid mixes with the solvent remaining in the polymer film. Therefore, the processing liquid easily penetrates into the inside of the polymer film. This can promote etching of the substrate.

In another embodiment of the present invention, the polymer film formed by the polymer film forming unit further contains an alkaline component.The substrate processing apparatus further includes a heating unit for heating the polymer film through the substrate.
According to this device, an alkaline component is contained in the polymer film together with the acidic polymer, so that the acidic polymer is neutralized by the alkaline component and is almost inactivated, and removal of the oxide layer hardly starts.

The alkaline components can be evaporated by heating the polymer film through the substrate using a heating unit. This allows the acidic polymer in the polymer film to regain its activity. This makes it easier to control the timing of the start of etching the substrate.
In another embodiment of the present invention, the processing fluid supply unit includes an opposing member having an opposing surface facing the main surface of the substrate and an outlet opening in the opposing surface for ejecting the processing fluid toward the main surface of the substrate.

According to this configuration, the processing fluid can be discharged from the discharge port provided in the facing member, and therefore the atmosphere in the space between the facing surface and the main surface of the substrate can be replaced with the processing fluid more quickly than in a configuration in which the entire space in which the substrate is placed is replaced with the processing fluid.
In another embodiment of the present invention, the processing liquid is water. The substrate processing apparatus further includes a humidification unit that adjusts humidity of the processing fluid, a supply path through which the processing fluid whose humidity has been adjusted by the humidification unit is supplied to the discharge port, and a humidity measuring unit that measures humidity of the processing fluid passing through the supply path.

Therefore, the humidity of the processing fluid passing through the supply path can be adjusted by the humidity adjustment unit based on the humidity measured by the humidity measurement unit. This allows the humidity of the processing fluid passing through the supply path, i.e., the humidity of the processing fluid discharged from the discharge port, to be adjusted to a desired humidity. As a result, the humidity of the atmosphere in the space between the opposing surface and the main surface of the substrate can be adjusted to a humidity that can effectively promote etching of the substrate by the polymer film.

In another embodiment of the present invention, the processing fluid supply unit includes a processing fluid nozzle that ejects the processing fluid toward the main surface of the substrate and is movable along the main surface of the substrate.
According to this method, the processing fluid nozzle ejects the processing fluid toward the space adjacent to the main surface of the substrate while moving along the main surface of the substrate, and therefore, the processing fluid can be supplied quickly to a wide area of the polymer film on the main surface of the substrate, compared to a case where the processing fluid is supplied toward only a part of the space adjacent to the main surface of the substrate.

In another embodiment of the present invention, the substrate processing apparatus further includes a humidification unit that adjusts humidity of the processing fluid, a supply path through which the processing fluid, the humidity of which has been adjusted by the humidification unit, is supplied to an outlet of the processing fluid nozzle, and a humidity measuring unit that measures humidity of the processing fluid passing through the supply path.
Therefore, the humidity of the processing fluid passing through the supply path can be adjusted by the humidity adjustment unit based on the humidity measured by the humidity measurement unit. This allows the humidity of the processing fluid passing through the supply path, i.e., the humidity of the processing fluid discharged from the discharge port of the processing fluid nozzle, to be adjusted to a desired humidity. As a result, the humidity of the atmosphere in contact with the polymer film on the main surface of the substrate can be adjusted to a humidity that can effectively promote etching of the substrate by the polymer film.

FIG. 1 is a schematic cross-sectional view for explaining the structure of a surface layer of a substrate to be processed. FIG. 2A is a plan view for explaining the configuration of the substrate processing apparatus according to the first embodiment of the present invention. FIG. 2B is an elevational view for explaining the configuration of the substrate processing apparatus. FIG. 3 is a schematic cross-sectional view for explaining a configuration example of a wet processing unit provided in the substrate processing apparatus. FIG. 4 is a block diagram for explaining an example of a configuration relating to control of the substrate processing apparatus. FIG. 5 is a flow chart for explaining an example of the substrate processing performed by the substrate processing apparatus. FIG. 6A is a schematic diagram for explaining the state of the substrate during the substrate processing. FIG. 6B is a schematic diagram for explaining the state of the substrate during the substrate processing. FIG. 6C is a schematic diagram for explaining the state of the substrate during the substrate processing. FIG. 6D is a schematic diagram for explaining the state of the substrate during the substrate processing. FIG. 6E is a schematic diagram for explaining the state of the substrate during the substrate processing. FIG. 6F is a schematic diagram for explaining the state of the substrate when the substrate processing is being performed. FIG. 6G is a schematic diagram for explaining the state of the substrate when the substrate processing is being performed. FIG. 6H is a schematic diagram for explaining the state of the substrate when the substrate processing is being performed. FIG. 7 is a schematic diagram for explaining the change in the surface layer of the upper surface of the substrate during the substrate processing. FIG. 8 is a schematic diagram for explaining the structure of the surface layer of the substrate when the polymer film is formed. FIG. 9A is a schematic diagram for explaining how an oxide layer at a grain boundary is etched by an etching solution composed of a low-molecular-weight etching component. FIG. 9B is a schematic diagram for explaining how the oxide layer at the grain boundaries is etched by the polymer film. FIG. 10 is a schematic diagram for explaining a first example of a method for supplying a polymer-containing liquid to a substrate in the substrate processing apparatus. FIG. 11 is a schematic diagram for explaining a second example of the method for supplying the polymer-containing liquid to the substrate in the substrate processing apparatus. FIG. 12 is a flow chart for explaining a first modified example of the substrate processing performed by the substrate processing apparatus. FIG. 13 is a schematic diagram for explaining changes in the surface layer portion of the upper surface of the substrate caused by alternately repeating the formation and removal of an oxide layer in the substrate processing. FIG. 14 is a flow chart for explaining a second modified example of the substrate processing performed by the substrate processing apparatus. FIG. 15 is a schematic diagram for explaining the state of the substrate when the second modified example of the substrate processing is being performed. FIG. 16 is a flow chart for explaining a third modified example of the substrate processing performed by the substrate processing apparatus. FIG. 17 is a schematic diagram for explaining the state of the substrate when the third modified example of the substrate processing is being performed. FIG. 18 is a flow chart for explaining a fourth modified example of the substrate processing performed by the substrate processing apparatus. FIG. 19 is a flow chart for explaining a fifth modified example of the substrate processing performed by the substrate processing apparatus. FIG. 20 is a flow chart for explaining a sixth modified example of the substrate processing performed by the substrate processing apparatus. FIG. 21 is a schematic diagram for explaining a modified example of the substrate heating unit provided in the wet processing unit. FIG. 22 is a schematic diagram for explaining a modified example of the facing member provided in the wet processing unit. FIG. 23 is a schematic diagram for explaining a first modified example of the processing fluid nozzle provided in the wet processing unit. FIG. 24 is a schematic diagram for explaining a second modified example of the processing fluid nozzle provided in the wet processing unit. FIG. 25 is a schematic diagram for explaining a third modified example of the processing fluid nozzle provided in the wet processing unit. FIG. 26 is a plan view for explaining the configuration of the substrate processing apparatus according to the second embodiment. FIG. 27 is a schematic cross-sectional view for explaining a configuration example of a light irradiation processing unit provided in the substrate processing apparatus according to the second embodiment. FIG. 28 is a flowchart illustrating an example of substrate processing performed by the substrate processing apparatus according to the second embodiment. FIG. 29 is a schematic cross-sectional view for explaining a thermal processing unit provided in the substrate processing apparatus according to the second embodiment. FIG. 30 is a flowchart illustrating another example of the substrate processing performed by the substrate processing apparatus according to the second embodiment. Figure 31A is a schematic diagram for explaining the processing procedure of an etching experiment to observe the change in etching amount due to differences in processing methods, and is a schematic diagram for explaining a first processing procedure in which a substrate is etched with a liquid film of a polymer-containing liquid. FIG. 31B is a schematic diagram for explaining the processing procedure of the etching experiment, and is a schematic diagram for explaining a second processing procedure of etching the substrate with a polymer film. FIG. 31C is a schematic diagram for explaining the processing procedures of the etching experiment, and is a schematic diagram for explaining a third processing procedure in which a substrate is etched by a polymer film to which a processing fluid is supplied. FIG. 32 is a graph showing the results of the etching experiment.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
<Structure of the surface layer of the substrate to be processed>
1 is a schematic cross-sectional view for explaining the structure of a surface layer of a substrate W to be processed. The substrate W is a substrate such as a silicon wafer, and has a pair of main surfaces. At least one of the pair of main surfaces is a device surface on which a concave-convex pattern 120 is formed. One of the pair of main surfaces may be a non-device surface on which no devices are formed.

On the surface layer of the device surface, for example, an insulating layer 105 in which multiple trenches 122 are formed, and a processing target layer 102 formed in each trench 122 so that the surface is exposed, are formed. The insulating layer 105 has fine convex structures 121 located between adjacent trenches 122, and a bottom partition portion 123 that partitions the bottom of the trench 122. The multiple structures 121 and the multiple trenches 122 form an uneven pattern 120. The surface of the processing target layer 102 and the surface of the insulating layer 105 (structures 121) form at least a part of the main surface of the substrate W.

The insulating layer 105 is, for example, a silicon oxide (SiO ₂ ) layer or a low dielectric constant layer. The low dielectric constant layer is made of a low dielectric constant (Low-k) material that has a lower dielectric constant than silicon oxide. Specifically, the low dielectric constant layer is made of an insulating material (SiOC) in which carbon is added to silicon oxide.
The processing target layer 102 is, for example, a metal layer, a silicon layer, or the like, and is typically a copper wiring. The metal layer is formed, for example, by growing crystals by electroplating or the like using a seed layer (not shown) formed in the trench 122 by a method such as sputtering as a nucleus. The method for forming the metal layer is not limited to this method. The metal layer may be formed only by sputtering, or may be formed by other methods.

The treatment target layer 102 is oxidized to form an oxide layer 103 (see the two-dot chain line in FIG. 1). The oxide layer 103 is, for example, a metal oxide layer, typically a copper oxide layer.
Although not shown, a barrier layer and a liner layer may be provided between the processing target layer 102 and the insulating layer 105 in the trench 122. The barrier layer is, for example, tantalum nitride (TaN), and the liner layer is, for example, ruthenium (Ru) or cobalt (Co).

The trench 122 is, for example, linear. The width L of the linear trench 122 refers to the size of the trench 122 in the direction in which the trench 122 extends and in the direction perpendicular to the thickness direction T of the substrate W.
The width L of the plurality of trenches 122 is not all the same, and at least two or more types of widths L of the trenches 122 are formed near the surface layer of the substrate W. The width L is the width of the processing target layer 102 and the width of the oxide layer 103. The trenches 122 are not limited to being linear.

The width L of the trench 122 is, for example, not less than 20 nm and not more than 500 nm. The depth D of the trench 122 is the size of the trench 122 in the thickness direction T, and is, for example, not more than 200 nm.
When the trench 122 has a circular shape in a plan view (when viewed in the normal direction to the main surface of the substrate W), the width L corresponds to the diameter of the trench 122 .

The processing target layer 102 is formed, for example, by growing crystals by electroplating or the like using a seed layer (not shown) formed in the trench 122 by a technique such as sputtering as a nucleus.
The processing target layer 102 and the oxide layer 103 are composed of a plurality of crystal grains 110. The interfaces between the crystal grains 110 are called crystal grain boundaries 111. The crystal grain boundaries 111 are a type of lattice defect, and are formed by a disturbance in the atomic arrangement.

The narrower the width L of the trench 122, the harder the crystal grains 110 grow, and the wider the width L of the trench 122, the easier it is to grow. Therefore, the narrower the width L of the trench 122, the easier it is to form small crystal grains 110, and the wider the width L of the trench 122, the easier it is to form large crystal grains 110. In other words, the narrower the width L of the trench 122, the higher the crystal grain boundary density, and the wider the width L of the trench 122, the lower the crystal grain boundary density.

<Configuration of the Substrate Processing Apparatus According to the First Embodiment>
Fig. 2A is a plan view for explaining the configuration of the substrate processing apparatus 1 according to the first embodiment of the present invention, and Fig. 2B is an elevational view for explaining the configuration of the substrate processing apparatus 1.
The substrate processing apparatus 1 is a single-wafer processing apparatus that processes one substrate W at a time. In this embodiment, the substrate W has a disk shape. In this embodiment, the substrate W is processed in an orientation in which the device surface faces upward.

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 which contains a plurality of substrates W to be processed in the processing units 2, transport robots IR and CR which transport the substrates W between the load port LP and the processing units 2, and a controller 3 which controls the substrate processing apparatus 1.
The transport robot IR transports the substrate W between the carrier C and the transport robot CR. The transport robot CR transports the substrate W between the transport robot IR and the processing unit 2.

Each of the transport robots IR, CR 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.
The processing units 2 form four processing towers arranged at four horizontally spaced positions. Each processing tower includes a plurality of processing units 2 (three in this embodiment) stacked vertically (see FIG. 2B). The four processing towers are arranged two on each side of a transfer path TR extending from a load port LP toward the transfer robots IR and CR (see FIG. 2A).

In the first embodiment, the processing units 2 are wet processing units 2W that process the substrate W with a liquid. Each wet processing unit 2W includes a chamber 4 and a processing cup 7 arranged 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 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.

<Configuration of Wet Processing Unit>
FIG. 3 is a schematic cross-sectional view for explaining an example of the configuration of the wet processing unit 2W.
The wet processing unit 2W further includes a spin chuck 5 that rotates the substrate W about a rotation axis A1 (vertical axis) while holding the substrate W at a predetermined holding position, and a heater unit 6 that heats the substrate W held by the spin chuck 5. The rotation axis A1 is a vertical line passing through the center of the substrate W. The predetermined holding position is the position of the substrate W shown in Fig. 3, where the substrate W is held in a horizontal attitude.

The spin chuck 5 is an example of a substrate holding unit that holds the substrate W at a predetermined holding position, and is also an example of a substrate rotation unit that rotates the substrate W about the rotation axis A1. The spin chuck 5 is also called a substrate rotation and holding unit.
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 vertically, and a spin motor 23 that rotates the rotation shaft 22 around the central axis (rotation axis A1) of the rotation shaft 22.

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 spin motor 23 is an electric motor. The spin motor 23 rotates the rotation shaft 22, thereby rotating the spin base 21 and the multiple chuck pins 20 around the rotation axis A1. As a result, the substrate W is rotated around the rotation axis A1 together with the spin base 21 and the multiple chuck pins 20.

The multiple chuck pins 20 are movable between a closed position and an open position. The multiple chuck pins 20 are moved by an opening/closing mechanism 25. When the multiple chuck pins 20 are in the closed position, they contact the peripheral portion of the substrate W to grip the substrate W. When the multiple chuck pins 20 are in the open position, they release their grip on the peripheral portion of the substrate W, while contacting the peripheral portion of the lower surface (lower main surface) of the substrate W to support the substrate W from below.

The opening/closing mechanism 25 includes, for example, a link mechanism that moves the multiple chuck pins 20 and a drive source that applies a drive force to the link mechanism. The drive source includes, for example, an electric motor.
The heater unit 6 is an example of a substrate heating unit that heats the entire substrate W. The heater unit 6 has the form of a disk-shaped hot plate. The heater unit 6 is disposed between the upper surface of the spin base 21 and the lower surface of the substrate W. The heater unit 6 has a heating surface 6a that faces the lower surface of the substrate W from below.

The heater unit 6 includes a plate body 61 and a heater 62. The plate body 61 is slightly smaller than the substrate W in a plan view. The upper surface of the plate body 61 constitutes the heating surface 6a. The heater 62 may be a resistor built into the plate body 61. The heating surface 6a is heated by passing electricity through the heater 62. The heater 62 can heat the substrate W to a temperature approximately equal to the temperature of the heater 62.

The heater 62 is configured to be able to heat the substrate W in a temperature range from room temperature (for example, a temperature of 5° C. or more and 25° C. or less) to 400° C. or less. A current supply unit 64 is connected to the heater 62 via a power supply line 63. The temperature of the heater 62 is adjusted by adjusting the current supplied from the current supply unit 64 to the heater 62.
A lift shaft 66 is connected to the lower surface of the heater unit 6. The lift shaft 66 is inserted into a through hole 21a formed in the center of the spin base 21 and into the internal space of the rotation shaft 22. The heater unit 6 is lifted and lowered by a heater lift mechanism 65.

The heater lifting mechanism 65 includes, for example, an actuator (not shown), such as an electric motor or an air cylinder, which drives the lifting shaft 66 to move up and down. The heater lifting mechanism 65 lifts and lowers the heater unit 6 via the lifting shaft 66. The heater unit 6 can be lifted and lowered between the lower surface of the substrate W and the upper surface of the spin base 21.
When the heater unit 6 rises, it can receive the substrate W from the multiple chuck pins 20 that are positioned in the open position. The heater unit 6 can heat the substrate W by being disposed at a contact position where the heating surface 6a is in contact with the lower surface of the substrate W, or at a proximity position where the heater unit 6 is in close proximity to but not in contact with the lower surface of the substrate W. A position where the heater unit 6 is sufficiently retracted from the lower surface of the substrate W to such an extent that heating of the substrate W by the heater unit 6 is stopped is referred to as a retracted position.

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. 3) 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. 3) that receive liquid guided downward by the plurality of guards 30, and a cylindrical outer wall member 32 that surrounds the plurality of guards 30 and the plurality of cups 31.

The multiple guards 30 are individually raised and lowered by a guard lifting mechanism (not shown). Each guard 30 can move to an upper position where its upper end is located above the upper surface (upper main surface) of the substrate W, a lower position where its upper end is located below the upper surface of the substrate W, and any position between the upper and lower positions.
The processing unit 2 further includes an oxidizer nozzle 9 for supplying a liquid oxidizer such as hydrogen peroxide solution to the upper surface of the substrate W held on the spin chuck 5, a polymer-containing liquid nozzle 10 for supplying a polymer-containing liquid containing an acidic polymer and an alkaline component to the upper surface of the substrate W held on the spin chuck 5, and a rinsing liquid nozzle 11 for supplying a rinsing liquid such as DIW (deionized water) to the upper surface of the substrate W held on the spin chuck 5.

The liquid oxidizing agent is a liquid that oxidizes a surface portion of the layer to be treated that is exposed from the upper surface of the substrate W, thereby forming an oxide layer on the surface portion of the layer to be treated. The oxide layer formed by the liquid oxidizing agent has a thickness of, for example, 1 nm or more and 2 nm or less. However, the oxide layer formed by the liquid oxidizing agent may be smaller than 1 nm or larger than 2 nm.
The liquid oxidizing agent is, for example, hydrogen peroxide water (H ₂ O ₂ water) containing hydrogen peroxide (H ₂ O ₂ ) as an oxidizing agent, or ozone water (O ₃ water) containing ozone (O ₃ ) as an oxidizing agent.

The oxidizer does not necessarily have to be hydrogen peroxide or ozone. For example, the liquid oxidizer may contain multiple oxidizers, and specifically, the liquid oxidizer may be a liquid formed by dissolving both hydrogen peroxide and ozone in DIW. The oxidizer nozzle 9 is an example of a substrate oxidation unit.
The oxidizer nozzle 9 is a movable nozzle that is movable at least in the horizontal direction. The oxidizer nozzle 9 is moved in the horizontal direction by a first nozzle moving mechanism 33. The first nozzle moving mechanism 33 includes an arm (not shown) that is connected to the oxidizer nozzle 9 and extends horizontally, and an arm moving unit (not shown) that moves the arm in the horizontal direction. The arm moving unit may have an electric motor or an air cylinder, or may have an actuator other than these. The nozzle moving mechanism described below has a similar configuration.

The oxidant nozzle 9 may be movable in the vertical direction. By moving in the vertical direction, the oxidant nozzle 9 can approach the upper surface of the substrate W or retract upward from the upper surface of the substrate W. Unlike this embodiment, the oxidant nozzle 9 may be a fixed nozzle whose horizontal and vertical positions are fixed.
The oxidizer nozzle 9 is connected to one end of an oxidizer pipe 40 that guides liquid oxidizer to the oxidizer nozzle 9. The other end of the oxidizer pipe 40 is connected to an oxidizer tank (not shown) that stores the liquid oxidizer. The oxidizer pipe 40 is provided with an oxidizer valve 50A that opens and closes the flow path in the oxidizer pipe 40, and an oxidizer flow rate adjustment valve 50B that adjusts the flow rate of the liquid oxidizer in the flow path.

When the oxidizer valve 50A is opened, the liquid oxidizer is discharged downward in a continuous flow from the discharge port of the oxidizer nozzle 9 at a flow rate that corresponds to the opening degree of the oxidizer flow rate adjustment valve 50B.
The polymer-containing liquid contains a solute and a solvent that dissolves the solute. The solute of the polymer-containing liquid includes an acidic polymer and an alkaline component.
The acidic polymer is an acidic polymer that dissolves an oxidized layer without oxidizing the layer to be treated. The acidic polymer is a solid or liquid at room temperature, and exhibits acidity by releasing protons in a solvent.

The molecular weight of the acidic polymer is, for example, 1000 or more and 100,000 or less. The acidic polymer is not limited to polyacrylic acid. The acidic polymer is, for example, a carboxy group-containing polymer, a sulfo group-containing polymer, or a mixture thereof. The carboxylic acid polymer is, for example, polymaleic acid, polyacrylic acid, a carboxyvinyl polymer (carbomer), carboxymethyl cellulose, or a mixture thereof. In other words, the carboxylic acid polymer may contain, for example, at least one of polymaleic acid, polyacrylic acid, a carboxyvinyl polymer, and carboxymethyl cellulose. The sulfo group-containing polymer is, for example, polystyrene sulfonic acid, polyvinyl sulfonic acid, or a mixture thereof. The sulfo group-containing polymer may contain, for example, at least one of polystyrene sulfonic acid and polyvinyl sulfonic acid.

The solvent contained in the polymer-containing liquid is preferably a substance that is liquid at room temperature, has affinity for the acidic polymer, and evaporates by rotation or heating of the substrate W. Having affinity for the acidic polymer means that the solvent can dissolve or swell the acidic polymer.
The solvent contained in the polymer-containing liquid is not limited to DIW, but is preferably an aqueous solvent. The solvent contains at least one of DIW, carbonated water, electrolytic ion 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).

The alkaline component is, for example, ammonia. The alkaline component is not limited to ammonia. Specifically, the alkaline component includes, for example, ammonia, tetramethylammonium hydroxide (TMAH), dimethylamine, or a mixture thereof. In other words, the alkaline component may include, for example, at least one of ammonia, TMAH, and dimethylamine.

The alkaline component is preferably a component that exhibits alkalinity in the solvent and evaporates when heated to a temperature below the boiling point of the solvent. The alkaline component is preferably composed of a component that is in a gaseous state at room temperature. Therefore, the alkaline component is particularly preferably ammonia, dimethylamine, or a mixture thereof.
The polymer-containing liquid nozzle 10 is a movable nozzle that is movable at least in the horizontal direction. The polymer-containing liquid nozzle 10 is moved in the horizontal direction by a second nozzle moving mechanism 34 having a configuration similar to that of the first nozzle moving mechanism 33. The polymer-containing liquid nozzle 10 may be movable in the vertical direction. Unlike this embodiment, the polymer-containing liquid nozzle 10 may be a fixed nozzle whose horizontal and vertical positions are fixed.

The polymer-containing liquid nozzle 10 is connected to one end of a polymer-containing liquid pipe 41 that guides the polymer-containing liquid to the polymer-containing liquid nozzle 10. The other end of the polymer-containing liquid pipe 41 is connected to a polymer-containing liquid tank (not shown). The polymer-containing liquid pipe 41 is equipped with a polymer-containing liquid valve 51A that opens and closes the flow path in the polymer-containing liquid pipe 41, and a polymer-containing liquid flow rate adjustment valve 51B that adjusts the flow rate of the polymer-containing liquid in the flow path.

When the polymer-containing liquid valve 51A is opened, the polymer-containing liquid is discharged downward in a continuous flow from the discharge port of the polymer-containing liquid nozzle 10 at a flow rate according to the opening of the polymer-containing liquid flow rate control valve 51B.
At least a part of the solvent evaporates from the polymer-containing liquid supplied to the upper surface of the substrate W, and the polymer-containing liquid on the substrate W changes into a semi-solid or solid polymer film. The semi-solid state refers to a state in which a solid component and a liquid component are mixed, or a state in which the polymer has a viscosity sufficient to maintain a certain shape on the substrate W. The solid state refers to a state in which no liquid component is contained and which is composed only of solid components. A polymer film in which the solvent remains is semi-solid, and a polymer film in which the solvent has completely disappeared is solid.

The polymer-containing liquid contains an alkaline component as a solute in addition to the acidic polymer, and therefore the polymer film contains both the acidic polymer and the alkaline component.
When the polymer film contains an alkaline component and an acidic polymer, the polymer film is neutral. That is, the acidic polymer is neutralized by the alkaline component and is almost inactivated. Therefore, the oxidized layer of the substrate W is not dissolved by the action of the acidic polymer. If the polymer film is heated to evaporate the alkaline component from the polymer film, the activity of the acidic polymer is restored. That is, the oxidized layer of the substrate W is dissolved by the action of the acidic polymer.

It is preferable that the solvent does not evaporate completely but remains in the polymer film. If this is the case, the acidic polymer in the polymer film can fully exhibit its acidic function, and the oxide layer can be removed efficiently. If the solvent remains, the polymer film will be neutral when alkaline components are present in the polymer film, and will be acidic after the alkaline components have evaporated.

In addition, by evaporating the solvent in the polymer film appropriately, the concentration of the acidic polymer component dissolved in the solvent in the polymer film can be increased. This allows the oxide layer to be removed efficiently. In addition, the higher the temperature of the polymer film, the more the chemical reaction by the acidic polymer to remove (dissolve) the oxide layer is promoted. In other words, the acidic polymer has the property that the higher the temperature, the faster the oxide layer is removed. Therefore, the oxide layer can be removed efficiently by heating the polymer film formed on the upper surface of the substrate W.

The rinsing liquid functions as an oxidizing agent removal liquid that removes (washes away) the liquid oxidizing agent adhering to the upper surface of the substrate W, and also functions as a polymer removal liquid that dissolves the polymer film formed on the upper surface of the substrate W and removes it from the main surface of the substrate W.
The rinse liquid is not limited to DIW. The rinse liquid contains at least one of DIW, carbonated water, electrolytic ion water, hydrochloric acid water with a dilute concentration (for example, 1 ppm or more and 100 ppm or less), ammonia water with a dilute concentration (for example, 1 ppm or more and 100 ppm or less), and reduced water (hydrogen water). That is, the rinse liquid may be a liquid similar to the solvent of the polymer-containing liquid. If DIW is used as both the rinse liquid and the solvent of the polymer-containing liquid, the number of types of liquids (substances) used can be reduced.

The rinsing liquid nozzle 11 is an example of a rinsing liquid supply unit that supplies the rinsing liquid to the upper surface of the substrate W. In this embodiment, the rinsing liquid nozzle 11 is a fixed nozzle whose horizontal and vertical positions are fixed. Unlike this embodiment, the rinsing liquid nozzle 11 may be a movable nozzle that is movable at least in the horizontal direction.
The rinsing liquid nozzle 11 is connected to one end of a rinsing liquid pipe 42 that guides the rinsing liquid to the rinsing liquid nozzle 11. The other end of the rinsing liquid pipe 42 is connected to a rinsing liquid tank (not shown). A rinsing liquid valve 52A that opens and closes a flow path in the rinsing liquid pipe 42, and a rinsing liquid flow rate adjustment valve 52B that adjusts the flow rate of the rinsing liquid in the flow path are interposed in the rinsing liquid pipe 42. When the rinsing liquid valve 52A is opened, the rinsing liquid discharged in a continuous flow from the discharge port of the rinsing liquid nozzle 11 lands on the upper surface of the substrate W.

The wet processing unit 2W further includes an opposing member 8 that faces the upper surface of the substrate W held by the spin chuck 5 at a distance from the upper surface of the substrate W. The opposing member 8 has an opposing surface 8a that faces the upper surface of the substrate W held by the spin chuck 5 from above. The opposing member 8 is formed in a disk shape having a diameter substantially the same as or greater than that of the substrate W. A support shaft 28 is fixed to the opposing member 8 on the side opposite to the opposing surface 8a.

The opposing member 8 is connected to an opposing member lifting mechanism 26 that lifts and lowers the opposing member 8. The opposing member lifting mechanism 26 includes, for example, an actuator (not shown) such as an electric motor or an air cylinder that drives the support shaft 28 to lift and lower. The opposing member 8 may be rotatable about the rotation axis A1.
The facing member 8 is raised and lowered by the facing member lifting mechanism 26 between an upper position, which is the upper limit position of the movable range of the facing member 8, and a lower position, which is the lower limit position of the movable range of the facing member 8. The facing member 8 can be positioned at a separation position where each moving nozzle (oxidizer nozzle 9 and polymer-containing liquid nozzle 10) can pass between the facing member 8 and the substrate W. The separation position is, for example, the upper position. The facing member 8 can be positioned at a blocking position where the atmosphere in the space SP1 between the facing member 8 and the upper surface of the substrate W held by the spin chuck 5 is blocked from the atmosphere outside the space SP1. Therefore, the facing member 8 is also called a blocking plate. The blocking position is, for example, the lower position.

The opposing member 8 has an outlet 8b that opens on the opposing surface 8a and that discharges the treatment fluid. The treatment fluid discharged from the outlet 8b is a fluid that contains at least one of a mist of a treatment liquid and a vapor of the treatment liquid. The treatment liquid is a liquid that has an affinity for acidic polymers. The mist refers to a plurality of minute droplets of the treatment liquid suspended in space.
The processing fluid does not need to be composed of at least one of the mist and vapor of the processing liquid, but may contain at least one of the mist and vapor of the processing liquid and a carrier gas. The carrier gas is a gas for sending the mist and vapor of the processing liquid to the discharge port 8b. Examples of the carrier gas include an inert gas or air.

The inert gas is, for example, nitrogen (N ₂ ) gas. The inert gas is a gas that does not react with the processing target layer and the oxide layer. The inert gas is not limited to nitrogen gas, and may be, for example, a rare gas such as argon (Ar) gas, or a mixed gas of nitrogen gas and a rare gas. That is, the inert gas may be a gas containing at least one of nitrogen gas and a rare gas.

The treatment liquid is, for example, water such as DIW, but is not limited to water. The treatment liquid does not need to be composed of only a single substance, and may be, for example, a liquid in which a small amount of organic solvent is contained in water such as DIW. The treatment liquid is preferably a liquid that is miscible with the solvent contained in the polymer-containing liquid.
In the following, this embodiment will be described assuming that the processing liquid is DIW. When the processing liquid is DIW, the processing fluid contains at least one of a mist of DIW and water vapor (steam of DIW).

The wet processing unit 2W is provided with a configuration for supplying a processing fluid to the discharge port 8b. Specifically, the wet processing unit 2W includes a humidification unit 36 that forms a processing fluid from DIW and adjusts the humidity of the processing fluid, a DIW supply pipe 43 that sends liquid DIW from a DIW supply source (not shown) to the humidification unit 36, a supply path 37 that supplies the processing fluid from the humidification unit 36 to the discharge port 8b, and a humidity measurement unit 38 such as a hygrometer that measures the humidity of the processing fluid passing through the supply path 37.

The humidification unit 36 is, for example, a humidifier. The humidifier may be an ultrasonic, heating, vaporization, or hybrid humidifier. An ultrasonic humidifier uses ultrasonic waves to vibrate the DIW to form a process fluid. A heating humidifier heats the DIW with a heater or the like to form a process fluid. An vaporization humidifier sprays a carrier gas onto a filter that holds the DIW to form a process fluid. A hybrid humidifier sprays a carrier gas heated with a heater or the like onto a filter that holds the DIW to form a process fluid.

The supply path 37 is disposed in the facing member 8 and includes a treatment fluid nozzle 12 that discharges a treatment fluid, and a treatment fluid pipe 44 that is connected to the treatment fluid nozzle 12 and supplies the treatment fluid to the treatment fluid nozzle 12. An outlet 12a of the treatment fluid nozzle 12 is connected to an outlet 8b of the facing member 8.
A process fluid valve 54A for opening and closing a flow path in the process fluid pipe 44, and a process fluid flow rate control valve 54B for controlling the flow rate of the process fluid in the flow path are interposed in the process fluid pipe 44. When the process fluid valve 54A is opened, the process fluid is discharged from the discharge port 8b at a flow rate according to the opening degree of the process fluid flow rate control valve 54B.

The humidity measuring unit 38 is, for example, a hygrometer. Humidity is a value expressed as a ratio of the actual amount of moisture in the processing fluid when the saturated water vapor amount of the processing fluid is set to 1. The humidity measuring unit 38 is preferably provided at a position close to the discharge port 8b in the supply path 37. In the example shown in FIG. 3, the humidity measuring unit 38 is attached, for example, to the tip of the processing fluid nozzle 12.

3, the humidity measuring unit 38 may be provided on the side of the substrate W. Specifically, the humidity measuring unit 38 may be attached to the guard 30.
The humidity of the processing fluid is preferably higher than the humidity of the clean room in which the substrate processing apparatus 1 is arranged, but not higher than 100%. The humidity of the clean room is, for example, 50%, but may be lower or higher than 50%. The humidity of the processing fluid is more preferably 80% or higher and not higher than 100%. The humidity of the processing fluid is even more preferably 85% or higher and not higher than 95%.

<Electrical configuration of the substrate processing apparatus>
4 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 objects to be controlled in the substrate processing apparatus 1 according to a predetermined control program. Specifically, the controller 3 includes a processor (CPU) 3A and a memory 3B in which the control program is stored. The controller 3 is configured to perform various controls for substrate processing by the processor 3A executing the control program.

In particular, the controller 3 is programmed to control the transport robots IR, CR, the spin motor 23, the opening/closing mechanism 25, the opposing member lifting mechanism 26, the first nozzle moving mechanism 33, the second nozzle moving mechanism 34, the third nozzle moving mechanism 35, the humidification unit 36, the humidity measurement unit 38, the energizing unit 64, the heater lifting mechanism 65, the oxidizer valve 50A, the oxidizer flow rate control valve 50B, the polymer-containing liquid valve 51A, the polymer-containing liquid flow rate control valve 51B, the rinse liquid valve 52A, the rinse liquid flow rate control valve 52B, the process fluid valve 54A, the process fluid flow rate control valve 54B, and the like.

The controller 3 controls the valves to control whether or not the fluid is discharged from the corresponding nozzle and the flow rate of the fluid discharged from the corresponding nozzle. Each of the following steps is executed by the controller 3 controlling these components. In other words, the controller 3 is programmed to execute each of the following steps.
<Substrate Processing According to First Embodiment>
Fig. 5 is a flow chart for explaining an example of substrate processing performed by the substrate processing apparatus 1. Figs. 6A to 6H are schematic views for explaining the state of each step of the substrate processing performed by the substrate processing apparatus 1.

The substrate processing performed by the substrate processing apparatus 1 will be described below mainly with reference to Figures 3 and 5. Figures 6A to 6H will also be referenced as appropriate.
First, an unprocessed substrate W is carried from the carrier C into the wet processing unit 2W by the transport robots IR, CR (see FIG. 2A ) and handed over to the multiple chuck pins 20 of the spin chuck 5 (substrate carrying step: step S1). The opening/closing mechanism 25 moves the multiple chuck pins 20 to the closed position, whereby the substrate W is gripped by the multiple chuck pins 20. As a result, the substrate W is held horizontally by the spin chuck 5 (substrate holding step). With the substrate W held by the spin chuck 5, the spin motor 23 starts rotating the substrate W (substrate rotation step).

Next, after the transport robot CR retreats from the wet processing unit 2W, a liquid oxidizing agent supplying step (step S2) is performed to supply liquid oxidizing agent to the upper surface of the substrate W. Specifically, first, the opposing member 8 is positioned at the separated position by the opposing member lifting mechanism 26. The opposing member 8 is positioned at the separated position until the processing fluid supplying step (step S7) described later is started. With the opposing member 8 positioned at the separated position, the first nozzle moving mechanism 33 moves the oxidizing agent nozzle 9 to the processing position. The processing position of the oxidizing agent nozzle 9 is, for example, a central position where the oxidizing agent nozzle 9 faces the central region of the upper surface of the substrate W. The central region of the upper surface of the substrate W is a region that includes the center of the upper surface of the substrate W and the periphery of the center.

With the oxidant nozzle 9 in the processing position, the oxidant valve 50A is opened, whereby liquid oxidant is supplied (discharged) from the oxidant nozzle 9 toward the central region of the upper surface of the substrate W (liquid oxidant supply step, liquid oxidant discharge step), as shown in FIG.
The liquid oxidizing agent supplied to the upper surface of the substrate W spreads over the entire upper surface of the substrate W due to centrifugal force. The liquid oxidizing agent that reaches the peripheral portion of the upper surface of the substrate W is discharged from the peripheral portion of the upper surface of the substrate W to the outside of the substrate W. By supplying the liquid oxidizing agent to the upper surface of the substrate W, an oxide layer is formed on the processing target layer exposed from the upper surface of the substrate W (oxidation layer forming step, wet oxidation step). By oxidizing the processing target layer (the surface layer portion of the upper surface of the substrate W), a substrate W having an upper surface on which an oxide layer is exposed is prepared (substrate preparation step). In this substrate processing, the substrate W can be oxidized by a simple step called wet oxidation processing in which a liquid oxidizing agent is supplied to the main surface of the substrate.

While the liquid oxidizing agent is being supplied to the upper surface of the substrate W, the heater unit 6 may be used to heat the liquid oxidizing agent via the substrate W. Specifically, the heater unit 6 is disposed in close proximity to the rotating substrate W to heat it. By heating the liquid oxidizing agent, the formation of an oxide layer is promoted (oxide layer formation promoting step).
Unlike Fig. 6A, the heater unit 6 may be disposed at the contact position while the liquid oxidizing agent is being supplied. Unlike Fig. 6A, the heater unit 6 may be disposed at the retracted position while the liquid oxidizing agent is being supplied, and heating of the substrate W may be stopped.

After the supply of liquid oxidizing agent continues for a predetermined time, an oxidizing agent removal process (step S3) is performed in which a rinsing liquid is supplied to the upper surface of the substrate W and the liquid oxidizing agent is removed from the upper surface of the substrate W. Specifically, the oxidizing agent valve 50A is closed and the rinsing liquid valve 52A is opened. This stops the supply of liquid oxidizing agent to the upper surface of the substrate W, and instead, as shown in FIG. 6B, the supply (discharge) of rinsing liquid from the rinsing liquid nozzle 11 to the upper surface of the substrate W is started (rinsing liquid supply process, rinsing liquid discharge process). This replaces the liquid oxidizing agent on the substrate W with the rinsing liquid, and the liquid oxidizing agent is removed from the upper surface of the substrate W.

After the oxidant valve 50A is closed, the first nozzle movement mechanism 33 moves the oxidant nozzle 9 to the retracted position. When the oxidant nozzle 9 is located at the retracted position, it does not face the top surface of the substrate W and is located outside the processing cup 7 in a plan view.
After the supply of the rinsing liquid is continued for a predetermined time, a polymer-containing liquid supplying step (step S4) of supplying a polymer-containing liquid onto the upper surface of the substrate W is performed.

Specifically, the second nozzle movement mechanism 34 moves the polymer-containing liquid nozzle 10 to the processing position. The processing position of the polymer-containing liquid nozzle 10 is, for example, a central position where the polymer-containing liquid nozzle 10 faces the central region of the upper surface of the substrate W. With the polymer-containing liquid nozzle 10 positioned at the processing position, the polymer-containing liquid valve 51A is opened. As a result, as shown in FIG. 6C, the polymer-containing liquid is supplied (discharged) from the polymer-containing liquid nozzle 10 toward the central region of the upper surface of the substrate W (polymer-containing liquid supply process, polymer-containing liquid discharge process).

The polymer-containing liquid discharged from the polymer-containing liquid nozzle 10 lands on the central region of the upper surface of the substrate W.
When the polymer-containing liquid is supplied to the upper surface of the substrate W, the substrate W may be rotated at a low speed (for example, 10 rpm) (low-speed rotation step). Alternatively, when the polymer-containing liquid is supplied to the upper surface of the substrate W, the rotation of the substrate W may be stopped. By slowing down the rotation speed of the substrate W or stopping the rotation of the substrate W, the polymer-containing liquid supplied to the substrate W remains in the central region of the upper surface of the substrate W. This allows the amount of polymer-containing liquid used to be reduced compared to the case where the substrate W is rotated at high speed to discharge the polymer-containing liquid on the upper surface of the substrate W to the outside of the substrate W.

Next, as shown in Figures 6D and 6E, a polymer film formation process (step S5) is performed in which a solid or semi-solid polymer film 101 (see Figure 6E) is formed on the upper surface of the substrate W by evaporating at least a portion of the solvent in the polymer-containing liquid on the upper surface of the substrate W.
Specifically, the polymer-containing liquid valve 51A is closed to stop the discharge of the polymer-containing liquid from the polymer-containing liquid nozzle 10. After the polymer-containing liquid valve 51A is closed, the polymer-containing liquid nozzle 10 is moved to the retracted position by the second nozzle moving mechanism 34. When the polymer-containing liquid nozzle 10 is located at the retracted position, it does not face the upper surface of the substrate W and is located outside the processing cup 7 in a plan view.

After the polymer-containing liquid valve 51A is closed, as shown in FIG. 6D, the rotation of the substrate W is accelerated so that the rotation speed of the substrate W becomes a predetermined spin-off speed (rotation acceleration process). The spin-off speed is, for example, 1500 rpm. The rotation of the substrate W at the spin-off speed is continued for, for example, 30 seconds. The centrifugal force caused by the rotation of the substrate W causes the polymer-containing liquid remaining in the central region of the upper surface of the substrate W to spread toward the peripheral portion of the upper surface of the substrate W, and is spread over the entire upper surface of the substrate W. As shown in FIG. 6D, a part of the polymer-containing liquid on the substrate W is scattered from the peripheral portion of the substrate W to the outside of the substrate W, and the liquid film of the polymer-containing liquid on the substrate W is thinned (spin-off process). The polymer-containing liquid on the upper surface of the substrate W does not need to be scattered outside the substrate W, and it is sufficient that it spreads over the entire upper surface of the substrate W due to the action of the centrifugal force of the rotation of the substrate W.

The centrifugal force caused by the rotation of the substrate W acts not only on the polymer-containing liquid on the substrate W, but also on the gas in contact with the polymer-containing liquid on the substrate W. Therefore, the centrifugal force forms an airflow in which the gas flows from the center to the periphery of the upper surface of the substrate W. This airflow removes the gaseous solvent in contact with the polymer-containing liquid on the substrate W from the atmosphere in contact with the substrate W. Therefore, as shown in FIG. 6E, evaporation (volatilization) of the solvent from the polymer-containing liquid on the substrate W is promoted, and a solid or semi-solid polymer film 101 is formed (polymer film formation process). In this way, the polymer-containing liquid nozzle 10 functions as a polymer film formation unit.

Since the polymer film 101 has a higher viscosity than hydrofluoric acid and the polymer-containing liquid, it is not completely removed from the substrate W and remains on the substrate W even though the substrate W is rotating. In this embodiment, the polymer-containing liquid that has remained in the central region of the upper surface of the substrate W is spread over the entire upper surface of the substrate W by centrifugal force to form the polymer film 101, so the amount of polymer-containing liquid used can be reduced compared to the case where the polymer film 101 is formed by evaporating the solvent from the liquid film of the polymer-containing liquid that covers the entire upper surface of the substrate W.

Immediately after the polymer film 101 is formed, the polymer film 101 contains an alkaline component, and therefore the acidic polymer in the polymer film 101 is almost inactivated, so that the oxide layer is hardly removed.
Next, a polymer film heating step (step S6) is performed to heat the polymer film 101 on the substrate W. Specifically, as shown in Fig. 6F, the heater unit 6 is disposed in a proximal position to heat the substrate W (substrate heating step, heater heating step).

After the polymer film 101 is formed, etching of the substrate W hardly starts until the polymer film 101 is heated. The polymer film 101 formed on the substrate W is heated through the substrate W. By heating the polymer film 101, the alkaline components evaporate and the acidic polymer regains activity (alkaline component evaporation process, alkaline component removal process). Therefore, etching of the substrate W starts due to the action of the acidic polymer in the polymer film 101 (etching start process, etching process). More specifically, removal of the oxide layer formed on the surface portion of the upper surface of the substrate W starts (oxide layer removal start process, oxide layer removal process).

As described above, the acidic polymer has a property that the higher the temperature, the faster the removal rate of the oxide layer. Therefore, by continuing to heat the polymer film 101 even after the alkaline component has been removed from the polymer film 101, the removal of the oxide layer by the acidic polymer is promoted (removal promotion step).
Heating the polymer film 101 causes the solvent in the polymer film 101 to evaporate, increasing the concentration of the acidic polymer dissolved in the solvent in the polymer film 101 (polymer concentration step). This increases the concentration of the acidic polymer, improving the removal rate of the oxide layer due to the action of the acidic polymer.

It is preferable that the heating temperature of the substrate W is lower than the boiling point of the solvent in the polymer film 101. In this case, the solvent can be appropriately evaporated from the polymer film 101 on the substrate W. This makes it possible to increase the concentration of the acidic polymer dissolved in the solvent in the polymer film 101. Furthermore, it is possible to prevent the solvent from being completely evaporated and removed from the polymer film 101.

Next, a processing fluid supplying step (step S7) of supplying a processing fluid toward the polymer film 101 on the substrate W is performed.
More specifically, the opposing member lifting mechanism 26 places the opposing member 8 in the blocking position (opposing member placing step). With the opposing member 8 in the blocking position, the humidification unit 36 is operated and the processing fluid valve 54A is opened. As a result, as shown in Fig. 6G, the processing fluid is discharged from the discharge port 8b of the opposing member 8. The processing fluid discharged from the discharge port 8b is supplied to the space SP1 between the opposing member 8 and the upper surface of the substrate W (strictly speaking, the surface of the polymer film 101). The space SP1 is a space in contact with the polymer film 101.

By spreading the processing fluid throughout the space SP1, the atmosphere in the space SP1 is replaced with the processing fluid. Therefore, compared to a configuration in which the entire space in which the substrate W is placed (the space within the chamber 4) is replaced with the processing fluid, the atmosphere in the space SP1 between the facing surface 8a and the upper surface of the substrate W can be replaced with the processing fluid more quickly. In this way, the facing member 8 and the processing fluid nozzle 12 function as a processing fluid supply unit.

By supplying the processing fluid to the space SP1, the polymer film 101 is exposed to an atmosphere containing the processing fluid. When the polymer film 101 comes into contact with the processing fluid, minute droplets of the processing liquid adhere to the surface of the polymer film 101. Unlike this embodiment, if a continuous flow of DIW is supplied to the top surface of the substrate W, depending on the amount of DIW supplied, the acidic polymer may be dissolved in the DIW, causing the polymer film 101 to be removed from the substrate W.

Therefore, as in this embodiment, a method of bringing the processing fluid into contact with the polymer film 101 allows an appropriate amount of DIW to be supplied to the polymer film 101 while maintaining the polymer film 101 on the upper surface of the substrate W. Since the processing liquid has an affinity for the acidic polymer, the DIW penetrates into the polymer film 101. This can promote the release of protons (hydrogen ions) from the acidic polymer. In other words, etching of the substrate W can be promoted.

Since the heating of the polymer film 101 is started before the start of the treatment fluid supplying step, the acidic polymer in the polymer film 101 has regained its activity due to the evaporation of the alkaline component from the polymer film 101 .
Even if most of the solvent is removed from the polymer film 101 in the polymer heating step (step S6), the supply of the processing fluid can provide an appropriate amount of DIW to the polymer film 101. Therefore, the reduction in the removal rate of the oxide layer 103 due to the removal of the solvent can be suppressed.

In addition, if most of the solvent is removed from the polymer film 101 in the polymer heating step (step S6), etching of the substrate W may not start sufficiently even if the alkaline components are removed from the polymer film 101 by the polymer heating step. In that case, etching of the substrate W starts by supplying DIW to the polymer film 101 in the processing fluid supply step (step S7) (etching start step, etching step). More specifically, removal of the oxide layer formed on the surface portion of the upper surface of the substrate W starts (oxide layer removal start step, oxide layer removal step).

That is, in this embodiment, etching of the substrate W is started by carrying out either the polymer film heating step (step S6) or the processing fluid supplying step (step S7).
6G, while the processing fluid is being discharged from the discharge port 8b of the facing member 8, the heater unit 6 may continue to heat the substrate W (heating continuation step), thereby increasing the temperature of the acidic polymer and facilitating the removal of the oxidized layer by the acidic polymer (removal promotion step).

The humidity of the atmosphere in the space SP1 may also be adjusted by feedback control based on the measurement result of the humidity measurement unit 38. In particular, if the measurement result of the humidity measurement unit 38 is outside a predetermined reference humidity range, the controller 3 controls at least one of the humidification unit 36 and the process fluid flow rate adjustment valve 54B so that the measurement result of the humidity measurement unit 38 falls within the reference humidity range. This adjusts the humidity of the process fluid discharged from the discharge port 8b. The reference humidity range may be, for example, higher than the humidity of a clean room (e.g., 50%) and up to 100%, a range of 80% or more and up to 100%, or a range of 80% or more and up to 95%.

The atmosphere in the space SP1 is replaced by the processing fluid discharged from the discharge port 8b, so that the humidity of the atmosphere in the space SP1 gradually approaches the humidity of the processing fluid discharged from the discharge port 8b. Therefore, the humidity of the processing fluid discharged from the discharge port 8b is adjusted by the humidity of the processing fluid discharged from the discharge port 8b, so that the humidity of the atmosphere in the space SP1 can be substantially adjusted. As a result, the humidity of the atmosphere in the space SP1 between the opposing surface 8a and the main surface of the substrate W can be adjusted to a humidity that can effectively promote etching of the substrate W by the polymer film 101.

As shown by the dotted line in Figure 3, if the humidity measuring unit 38 is provided to the side of the substrate W, the humidity measuring unit 38 measures the humidity in the vicinity of the space SP1, and the measurement result can be used for feedback control.
A polymer film removal step (step S8) is performed on the polymer film 101 on the substrate W to remove the polymer film 101. Specifically, the facing member 8 is retreated to the separated position, and the rinsing liquid valve 52A is opened. As a result, as shown in Fig. 6H, the rinsing liquid is supplied (discharged) from the rinsing liquid nozzle 11 toward the central region of the upper surface of the substrate W on which the polymer film 101 is formed (rinsing liquid supply step, rinsing liquid discharge step).

The polymer film 101 on the substrate W is dissolved by the rinsing liquid supplied to the substrate W (polymer film dissolving process). By continuing to supply the rinsing liquid to the substrate W, the polymer film 101 is removed from the upper surface of the substrate W (polymer film removing process). The polymer film 101 is removed from the upper surface of the substrate W by the dissolving action of the rinsing liquid and the flow of the rinsing liquid formed on the upper surface of the substrate W (rinsing process).

After the polymer film 101 is removed from the upper surface of the substrate W by the rinsing liquid, a spin-dry step (step S9) is performed.
Specifically, the rinse liquid valve 52A is closed to stop the supply of the rinse liquid to the upper surface of the substrate W. Then, the spin motor 23 accelerates the rotation of the substrate W to rotate the substrate W at high speed. The substrate W is rotated at a drying speed, for example, 1500 rpm. As a result, a large centrifugal force acts on the rinse liquid on the substrate W, and the rinse liquid on the substrate W is scattered around the substrate W.

Then, the spin motor 23 stops the rotation of the substrate W. The transport robot CR enters the wet processing unit 2W, receives the processed substrate W from the multiple chuck pins 20, and transports it out of the wet processing unit 2W (substrate transport step: step S10). The substrate W is handed over from the transport robot CR to the transport robot IR, which stores it in the carrier C.

FIG. 7 is a schematic diagram for explaining changes in the surface layer of the upper surface of the substrate W during substrate processing.
7(a) and 7(b), a liquid oxidizing agent is supplied to the upper surface of the substrate W, whereby an oxide layer 103 is formed on the surface of the layer to be treated 102 (oxidation layer forming step). The layer to be treated 102 is oxidized to prepare a substrate W having an upper surface on which the oxide layer 103 is exposed (substrate preparation step).

Then, a polymer-containing liquid is supplied to the upper surface of the substrate W, and at least a portion of the solvent in the polymer-containing liquid on the substrate W is evaporated to form a polymer film 101 on the upper surface of the substrate W, as shown in FIG. 7(c) (polymer film formation process).
7(d), the alkaline components are evaporated and removed from the polymer film 101 by heating the polymer film 101 (alkaline component evaporation step, alkaline component removal step). Then, as shown in FIG. 7(e), a processing fluid containing either water vapor or mist-like water is supplied to the polymer film 101, thereby facilitating etching of the oxide layer 103 by the acidic polymer in the polymer film 101 on the upper surface of the substrate W.

Due to the action of the acidic polymer in the polymer film 101 on the upper surface of the substrate W, the oxide layer 103 is dissolved and blended into the polymer film 101. As a result, as shown in Fig. 7(f), the oxide layer 103 is selectively removed from the upper surface of the substrate W (oxide layer removing step). Fig. 7(g) shows the state of the surface of the processing target layer 102 after the polymer film 101 has been removed.
According to the first embodiment, a polymer film 101 is formed on the top surface of the substrate W. The substrate W is then etched to remove the oxide layer 103 therefrom.

Since the polymer film 101 contains an acidic polymer, it has a higher viscosity than the polymer-containing liquid and liquids such as hydrofluoric acid. Therefore, the polymer film 101 is likely to remain on the upper surface of the substrate W. Therefore, it is not necessary to continuously supply the acidic polymer to the upper surface of the substrate W during the entire period during which the substrate W is etched. In other words, at least after the polymer film 101 is formed, it is not necessary to additionally supply the acidic polymer to the upper surface of the substrate W. Therefore, the amount of material (hydrofluoric acid or acidic polymer) required to etch the processing target layer 102 can be reduced compared to the case where the oxide layer 103 is removed using an etching liquid containing a low molecular weight etching component such as hydrofluoric acid.

Therefore, the amount of material used to etch the processing target layer 102 can be reduced.
As in the first embodiment, by etching the processing target layer 102 using the polymer film 101 containing an acidic polymer, the following effects are achieved.
When the oxide layer 103 is removed by a continuous flow of the etching liquid, the temperature of the etching liquid decreases as the etching liquid moves from the center to the peripheral edge of the upper surface of the substrate W. Therefore, due to the decrease in the temperature of the etching liquid, the amount of etching (amount of removal) in the peripheral region of the upper surface of the substrate W becomes smaller than the amount of etching in the central region of the upper surface of the substrate W, and the uniformity of the amount of etching at each position on the upper surface of the substrate W may decrease.

On the other hand, according to the first embodiment, the entire upper surface of the substrate W is covered with a semi-solid or solid polymer film 101, and the oxide layer 103 is removed by the action of the acidic polymer in the polymer film 101. Therefore, when the polymer film 101 is formed, the acidic polymer does not move from the center side to the periphery side of the upper surface of the substrate W, so that the temperature of the parts of the polymer film 101 that contact each position on the upper surface of the substrate W changes almost uniformly. This makes it possible to improve the uniformity of the etching amount.

According to the first embodiment, the polymer film 101 is heated to evaporate the alkaline component, so that the acidic polymer in the polymer film 101 regains its activity. Therefore, etching of the substrate W can be prevented from starting during the formation of the polymer film 101.
Specifically, since it is possible to prevent etching of the substrate W from being started while the polymer-containing liquid is being supplied, it is possible to prevent variation in the timing of starting etching between a position on the upper surface of the substrate W where the polymer-containing liquid lands (for example, the central portion of the upper surface of the substrate W) and a position on the upper surface of the substrate W where it takes a certain amount of time for the polymer-containing liquid to spread (the peripheral portion of the upper surface of the substrate W). Therefore, it is possible to prevent variation in the timing of starting etching at each position on the upper surface of the substrate W.

Furthermore, in the first embodiment, since the substrate W is heated after the polymer film 101 is formed, the polymer film 101 on the upper surface of the substrate W is heated as a whole, which further improves the uniformity of the etching amount.
Unlike the first embodiment, in the configuration in which the oxide layer 103 is removed with a continuous flow of etching liquid, when the width L of the trench 122 formed in the upper surface of the substrate W is narrow, the liquid entering the trench 122 may not be sufficiently replaced by the etching liquid. Therefore, when a plurality of trenches 122 having different widths L are formed in the upper surface of the substrate W, the degree of replacement of the liquid entering the trenches 122 by the etching liquid varies, and the uniformity of the amount of etching on the upper surface of the substrate W may be reduced.

On the other hand, according to the first embodiment, as shown in FIG. 8, the polymer film 101 is formed to conform to the processing target layer 102 and the trench 122, regardless of the width L of the trench 122. In particular, the polymer film 101 is formed to conform to the surface 103a of the oxide layer 103, the side surface 122a of the trench 122, and the top 121a of the structure 121. Therefore, even if trenches 122 having different widths L are formed, the variation in the amount of etching of the processing target layer 102 between the trenches 122 can be reduced.

9A and 9B, the distance between the constituent materials 116 that make up the oxide layer 103 at the grain boundary 111 is wider than the distance between the constituent materials 116 at the grain 110. Therefore, there are gaps 113 between the constituent materials 116 at the grain boundary 111. The constituent materials 116 are, for example, molecules, typically copper oxide molecules.

Unlike the first embodiment, as shown in FIG. 9A, when the oxide layer 103 is removed using an etching solution containing low molecular weight etching components 114 such as hydrofluoric acid, the low molecular weight etching components 114 tend to enter the gaps 113 present in the grain boundaries 111 of the substrate W. Therefore, referring also to FIG. 1, the oxide layer 103 is more likely to be removed in areas where the grain boundary density is high (inside the trench 122 with a narrow width L), and is less likely to be removed in areas where the grain boundary density is low (inside the trench 122 with a wide width L). Therefore, the processing target layer 102 is less likely to be etched uniformly, and the roughness (surface roughness) of the upper surface of the substrate W increases.

On the other hand, according to the first embodiment, as shown in Fig. 9B, the acidic polymer 115, which is a high molecular weight etching component, is less likely to enter the gaps 113 present in the crystal grain boundaries 111 than the low molecular weight etching component 114. Therefore, it is possible to reduce the variation in etching of the processing target layer 102 caused by the crystal grain boundary density. The roughness of the upper surface of the substrate W can be reduced.
Furthermore, according to the first embodiment, the following effects are achieved.

According to the first embodiment, the polymer film 101 can be formed by evaporating the solvent from the polymer-containing liquid supplied to the upper surface of the substrate W. Therefore, the concentration (density) of the acidic polymer in the polymer film 101 can be increased by the evaporation of the solvent. Therefore, the substrate W can be quickly etched by the high concentration (high density) of the acidic polymer.

Since the polymer film 101 is formed by at least a portion of the solvent evaporating from the polymer-containing liquid, the solvent may remain in the polymer film 101. If the solvent of the polymer-containing liquid and the processing liquid are both DIW, that is, if the solvent is a liquid that is miscible with the processing liquid, the DIW that adheres to the polymer film 101 when the polymer film 101 comes into contact with the processing fluid mixes with the solvent remaining in the polymer film 101. Therefore, the DIW easily penetrates into the inside of the polymer film. This can promote etching of the substrate W.

If the humidity of the processing fluid is higher than 50% and lower than 100%, a suitable amount of liquid DIW can be supplied to the polymer film 101. If the humidity of the processing fluid is higher than 80% and lower than 100%, a sufficient amount of DIW can be supplied to the polymer film 101. If the humidity of the processing fluid is higher than 85% and lower than 95%, a sufficient amount of DIW can be supplied to the polymer film 101 while easily controlling the amount of DIW supplied to the polymer film 101.

<Method of Supplying Polymer-Containing Liquid>
10 and 11 are schematic diagrams for explaining a first example and a second example of a method for supplying a polymer-containing liquid to a substrate W. For convenience of explanation, the spin chuck 5, the heater unit 6, the processing cup 7, the opposing member 8, the oxidizer nozzle 9, the rinse liquid nozzle 11, and the like are not shown in Figs.

In the first example of the supply method shown in FIG. 10, an acidic polymer liquid and an alkaline liquid are mixed in the mixing pipe 130 to form a polymer-containing liquid, and the polymer-containing liquid formed in the mixing pipe 130 is discharged from the polymer-containing liquid nozzle 10 to be supplied to the upper surface of the substrate W (polymer-containing liquid supplying process). The mixing pipe 130 is a pipe for mixing multiple liquids.

The acidic polymer liquid is a liquid containing an acidic polymer and a solvent, and the alkaline liquid is a liquid containing an alkaline component and a solvent. The solvent contained in these liquids is preferably the same type of liquid, for example, DIW. The polymer-containing liquid is a mixture of the acidic polymer liquid and the alkaline liquid.
The acidic polymer liquid is supplied from the acidic polymer liquid tank 141 to the mixing pipe 130 via the acidic polymer liquid pipe 131. The alkaline liquid is supplied from the alkaline liquid tank 142 to the mixing pipe 130 via the alkaline liquid pipe 132. The polymer-containing liquid formed in the mixing pipe 130 is supplied to the polymer-containing liquid nozzle 10 via the polymer-containing liquid pipe 41.

The acidic polymer liquid pipe 131 and the alkaline liquid pipe 132 are each provided with a plurality of valves (acidic polymer liquid valve 135A and alkaline liquid valve 136A) that open and close the flow paths in the corresponding pipes. The acidic polymer liquid pipe 131 and the alkaline liquid pipe 132 are each provided with a plurality of flow rate control valves (acidic polymer liquid flow rate control valve 135B and alkaline liquid flow rate control valve 136B) that adjust the flow rate of the liquid in the corresponding pipe.

A pH meter 129 may be branched and connected to the polymer-containing liquid pipe 41. The controller 3 may perform feedback control based on the pH detected by the pH meter 129. The feedback control is performed so that the pH of the polymer-containing liquid is maintained neutral by adjusting at least one of the acidic polymer liquid valve 135A, the alkaline liquid valve 136A, the acidic polymer liquid flow rate control valve 135B, and the alkaline liquid flow rate control valve 136B.

In the second example of the polymer-containing liquid supply method shown in FIG. 11, the polymer-containing liquid is supplied from the polymer-containing liquid tank 140 to the polymer-containing liquid nozzle 10 via the polymer-containing liquid piping 41. The polymer-containing liquid tank 140 is replenished with an acidic polymer liquid and an alkaline liquid via an acidic polymer liquid replenishment pipe 145 and an alkaline liquid replenishment pipe 146, respectively. The polymer-containing liquid is formed by mixing the acidic polymer liquid and the alkaline liquid in the polymer-containing liquid tank 140. The polymer-containing liquid is a mixture of the acidic polymer liquid and the alkaline liquid.

The polymer-containing liquid tank 140 may be provided with a pH meter 129. The controller 3 may perform feedback control based on the pH detected by the pH meter 129. The feedback control is performed by adjusting a plurality of refill valves 148 respectively installed in a plurality of refill pipes (acidic polymer liquid refill pipe 145 and alkaline liquid refill pipe 146) so that the pH of the polymer-containing liquid is maintained neutral.

<First Modification of Substrate Processing by the Substrate Processing Apparatus According to the First Embodiment>
12 is a flow chart for explaining a first modified example of the substrate processing performed by the substrate processing apparatus 1. In the first modified example of the substrate processing, after the first polymer film removal step (step S8) is completed, a cycle process including the liquid oxidizing agent supply step (step S2) to the polymer film removal step (step S8) is performed one or more times. "N" in FIG. 12 means a natural number.

The second and subsequent liquid oxidizing agent supplying steps are an example of a reforming step in which the surface layer of the upper surface of the substrate W is oxidized to form an oxide layer 103 after the polymer film removal step (rinsing step). By performing the cycle process, the oxide layer forming step and the oxide layer removing step are alternately repeated. In other words, the oxide layer forming step and the oxide layer removing step are alternately performed multiple times. The cycle process is performed multiple times, and after the final polymer film removal step (step S8), a spin drying step (step S9) is performed.

FIG. 13 is a schematic diagram for explaining a change in the surface layer of the upper surface of the substrate W caused by alternately repeating the formation and removal of the oxide layer 103 during substrate processing.
13A, by supplying a liquid oxidizing agent to the upper surface of the substrate W, an oxide layer 103 is formed on the surface of the layer to be treated 102 (oxidation layer forming step). By oxidizing the layer to be treated 102, a substrate W having an upper surface on which the oxide layer 103 is exposed is prepared (substrate preparation step).

Then, a polymer-containing liquid is supplied to the upper surface of the substrate W, and at least a portion of the solvent in the polymer-containing liquid on the substrate W is evaporated to form a polymer film 101 on the upper surface of the substrate W, as shown in FIG. 13(b) (polymer film formation process).
13(c), the alkaline components are evaporated and removed from the polymer film 101 by heating the polymer film 101 (alkaline component evaporation step, alkaline component removal step). Then, as shown in FIG. 13(d), a processing fluid containing water vapor or the like is supplied to the polymer film 101, thereby facilitating etching of the oxide layer 103 by the acidic polymer in the polymer film 101 on the upper surface of the substrate W.

The action of the acidic polymer in the polymer film 101 on the upper surface of the substrate W causes the oxide layer 103 to dissolve and dissolve into the polymer film 101. As a result, as shown in FIG. 13(e), the oxide layer 103 is selectively removed from the upper surface of the substrate W (oxide layer removal process). FIG. 13(f) shows the state of the surface of the processing target layer 102 after the polymer film 101 has been removed.

By performing the oxide layer forming step and the oxide layer removing step once each, the thickness of the processing target layer 102 to be oxidized is approximately constant (see FIGS. 13(a) and 13(g)). Therefore, the thickness of the removed oxide layer 103 (etching amount D1) is also approximately constant (see FIG. 13(e)).
13(h), by performing the cyclic treatment for a plurality of cycles, a portion of the treatment target layer 102 having a thickness D2 equivalent to the product of the thickness D1 and the number of cycles (three cycles in FIG. 13(h)) is removed from the substrate W (D2=D1×number of cycles). The amount of the treatment target layer 102 etched by performing the cyclic treatment for a plurality of cycles corresponds to the thickness D2. Therefore, by adjusting the number of times that the oxide layer forming step and the oxide layer removing step are repeatedly performed, a desired etching amount (the same amount as the thickness D2) can be achieved.

Thus, etching the target layer 102 stepwise at a constant etching amount is called digital etching. Also, etching the target layer 102 by repeatedly performing an oxide layer forming step and an oxide layer removing step is called cycle etching.
According to the first embodiment, the controller 3 controls the oxidant nozzle 9, the polymer-containing liquid nozzle 10, the spin base 21, etc., to alternately repeat oxidation of the processing target layer (formation of an oxide layer) and formation of the polymer film 101. By alternately repeating the formation of the oxide layer 103 and the removal of the oxide layer 103, the processing target layer 102 can be etched with high precision.

<Second Modification of Substrate Processing by the Substrate Processing Apparatus According to the First Embodiment>
Fig. 14 is a flow chart for explaining a second modified example of the substrate processing performed by the substrate processing apparatus 1. Fig. 15 is a schematic diagram for explaining the state of the substrate W when the second modified example of the substrate processing is being performed.
The substrate processing shown in FIG. 14 differs from the substrate processing shown in FIG. 5 mainly in that a heating and oxidation step (step S11) of forming an oxide layer by heating with a heater unit 6 is performed instead of the liquid oxidizing agent supplying step (step S2) and the oxidizing agent removing step (step S3).

In more detail, after the substrate W is loaded into the wet processing unit 2W, the substrate W held by the spin chuck 5 is heated to a predetermined oxidation temperature by the heater unit 6 (heating and oxidation process). As a result, the processing target layer exposed from the upper surface of the substrate W is oxidized to form an oxide layer (oxidation layer formation process). By oxidizing the processing target layer (the surface layer of the upper surface of the substrate W), a substrate W having an upper surface with an exposed oxide layer is prepared (substrate preparation process).

The predetermined oxidation temperature is, for example, a temperature not lower than 100° C. and not higher than 400° C. The oxide layer formed by heating has a thickness not lower than 10 nm and not higher than 20 nm, for example.
The heater unit 6 is disposed, for example, at a contact position as shown in Fig. 15. This allows the substrate W to be heated to a high temperature at which the layer to be processed is oxidized. In this substrate processing, the heater unit 6 functions as a substrate oxidation unit. As long as the layer to be processed of the substrate W can be oxidized, the heater unit 6 may be disposed at a proximity position.

Thereafter, the polymer-containing liquid supplying step (step S4) is performed. More specifically, the second nozzle moving mechanism 34 moves the polymer-containing liquid nozzle 10 to the processing position, and the polymer-containing liquid valve 51A is opened. As a result, the polymer-containing liquid is supplied to the upper surface of the substrate W.
Thereafter, a polymer film forming step (step S5) and a polymer film heating step (step S6) are performed. The heating temperature of the substrate W in the polymer film heating step (step S6) is preferably lower than the heating temperature of the substrate W in the thermal oxidation step. For example, the polymer film heating step (step S6) is preferably performed while disposing the heater unit 6 at a close position farther away from the substrate W than the contact position, as shown in FIG. 6F. At least, the position of the heater unit 6 in the polymer heating step (step S6) is preferably farther away from the substrate W than the position of the heater unit 6 in the thermal oxidation step. This makes it possible to start and promote the removal of the oxide layer 103 by the polymer film 101 while suppressing oxidation of the surface layer of the upper surface of the substrate W.

By adopting this substrate processing, the layer 102 (see FIG. 1) exposed from the top surface of the substrate W can be oxidized by heating the substrate W. That is, the oxide layer 103 (see FIG. 1) can be formed without using liquid. This reduces the amount of material (oxidizer) used to etch the layer 102. Furthermore, the oxide layer 103 is formed and removed while the substrate W is held on the same spin chuck 5. Therefore, since there is no need to move the substrate W, the oxide layer 103 can be removed more quickly than in a configuration in which the oxide layer 103 is formed and removed while the substrate W is held on separate spin chucks.

Furthermore, the heat of the substrate W, which is heated in order to oxidize the substrate W, can be utilized for heating the polymer film 101. As a result, the time required for substrate processing can be reduced.
Furthermore, by adopting this substrate processing method, the heater unit 6 used for forming the oxide layer 103 can also be used for heating to promote removal of the oxide layer 103. Therefore, there is no need to provide a heater for promoting removal of the oxide layer 103 separate from the heater unit 6 used for heating to oxidize the substrate W, and therefore the substrate processing can be simplified.

Furthermore, by using the heater unit 6 used for heating to form the oxide layer 103 also for heating to promote the removal of the oxide layer 103, the heat provided to the heater unit 6 for forming the oxide layer 103 can be used to heat the polymer film 101. Therefore, etching of the processing target layer 102 can be promoted more efficiently compared to a configuration in which a heater unit separate from the heater unit 6 used for oxidizing the oxide layer 103 is provided for heating the polymer film 101.

As shown by the two-dot chain line in FIG. 14, after the initial polymer film removal step (step S8) is completed, a cycle process consisting of the heating and oxidation step (step S11) to the polymer film removal step (step S8) may be performed one or more times.
<Third Modification of Substrate Processing by the Substrate Processing Apparatus According to the First Embodiment>
Fig. 16 is a flow chart for explaining a third modified example of the substrate processing performed by the substrate processing apparatus 1. Fig. 17 is a schematic diagram for explaining the state of the substrate W when the third modified example of the substrate processing is being performed. In the third modified example of the substrate processing, after the polymer film 101 is formed in the polymer film forming step (step S5), as shown in Fig. 17, the processing fluid supplying step (step S7) is performed without heating the polymer film 101.

In this substrate processing, the processing fluid is supplied to the space SP1 between the polymer film 101 and the opposing surface 8a without actively evaporating the alkaline components from the polymer film 101. Therefore, etching starts later than when the polymer film 101 is heated before supplying the processing fluid to the polymer film 101. However, since the alkaline components are gradually evaporated from the polymer film 101, etching of the substrate W by the polymer film 101 can start.

As shown by the two-dot chain line in FIG. 16, after the initial polymer film removal step (step S8) is completed, a cycle treatment including the liquid oxidizing agent supply step (step S2) to the polymer film removal step (step S8) may be performed one or more times.
<Fourth Modification of Substrate Processing by the Substrate Processing Apparatus According to the First Embodiment>
18 is a flow chart for explaining a fourth modified example of the substrate processing performed by the substrate processing apparatus 1. In the fourth modified example of the substrate processing, after the polymer film 101 is formed in the polymer film forming step (step S5), a processing fluid supply step (step S7) is performed in parallel with a polymer film heating step (step S6). In detail, the polymer film 101 is heated to evaporate the alkaline component, while a processing fluid is supplied to the space SP1 between the polymer film 101 and the facing surface 8a.

Therefore, the start of etching is delayed compared to the case where the polymer film 101 is heated before the processing fluid is supplied to the polymer film 101. However, the heating of the substrate W performed in parallel with the supply of the processing fluid causes the alkaline component to evaporate from the polymer film 101. As a result, etching of the substrate W by the polymer film 101 is started.
As shown by the two-dot chain line in FIG. 18, after the initial polymer film removal step (step S8) is completed, a cycle treatment consisting of the liquid oxidizing agent supply step (step S2) to the polymer film removal step (step S8) may be performed one or more times.

Fifth Modification of Substrate Processing by the Substrate Processing Apparatus According to the First Embodiment
19 is a flow chart for explaining a fifth modified example of the substrate processing performed by the substrate processing apparatus 1. The fifth modified example of the substrate processing is a substrate processing in which a substrate W on which an oxide layer 103 (see FIG. 1) has been formed in advance is used. In the fifth modified example of the substrate processing, first, a substrate W having a main surface on which the oxide layer 103 is exposed is prepared (substrate preparation process). Specifically, a carrier C containing a substrate W having an upper surface on which a first oxide layer is exposed is placed on a load port LP.

The substrate W having an upper surface on which the oxide layer 103 is exposed is carried from the carrier C into the wet processing unit 2W by the transport robots IR and CR (see FIG. 2A ) and handed over to the multiple chuck pins 20 of the spin chuck 5 (substrate carrying-in step: step S1). Thereafter, the polymer-containing liquid supplying step (step S4) to the substrate carrying-out step (step S10) are performed.
<Sixth Modification of Substrate Processing by the Substrate Processing Apparatus According to the First Embodiment>
FIG. 20 is a flow chart for explaining a sixth modified example of the substrate processing performed by the substrate processing apparatus 1. In FIG.

The sixth modified substrate processing example shown in FIG. 20 is similar to the substrate processing example shown in FIG. 19 in that it uses a substrate W on which an oxide layer 103 (see FIG. 1) has been formed in advance. However, unlike the substrate processing example shown in FIG. 19, the sixth modified substrate processing example performs the liquid oxidizing agent supply step (step S2) through the polymer film removal step (step S8) at least once each after the initial polymer film removal step (step S8). "M" in FIG. 20 represents an integer equal to or greater than 0.

The liquid oxidizing agent supplying step is an example of a reforming step in which, after the polymer film removing step (rinsing step), a surface layer of the upper surface of the substrate W is oxidized to form an oxide layer 103. By performing the cycle process, the oxide layer forming step and the oxide layer removing step are alternately repeated. In other words, the oxide layer forming step and the oxide layer removing step are alternately performed multiple times.
The cycle process is repeated several times, and the final polymer film removal process (step S7) is followed by a spin dry process (step S9). The formation and removal of the oxide layer 103 in the sixth modified example of the substrate processing is similar to that shown in FIG. 13, and therefore will not be described here.

<Modification of Wet Processing Unit 2W>
21 is a schematic diagram for explaining a modified example of the substrate heating unit provided in the wet processing unit 2 W. As shown in FIG. 21 , the wet processing unit 2 W may include, as the substrate heating unit, a heating fluid nozzle 13 for supplying a heating fluid for heating the substrate W toward the lower surface of the substrate W held by the spin chuck 5, instead of the heater unit 6.

The heating fluid nozzle 13 is, for example, inserted into a through hole 21a of the spin base 21. The discharge port 13a of the heating fluid nozzle 13 faces the central region of the lower surface of the substrate W from below.
The heating fluid nozzle 13 is connected to a heating fluid pipe 45 that guides the heating fluid to the heating fluid nozzle 13. The heating fluid pipe 45 is provided with a heating fluid valve 55A that opens and closes the flow path in the heating fluid pipe 45, and a heating fluid flow rate adjustment valve 55B that adjusts the flow rate of the heating fluid in the heating fluid pipe 45. A heater 55C (temperature adjustment unit) that adjusts the temperature of the heating fluid supplied to the heating fluid nozzle 13 may be provided.

When the heating fluid valve 55A is opened, the heating fluid is ejected in a continuous flow upward from the outlet 13a of the heating fluid nozzle 13 at a flow rate that depends on the opening degree of the heating fluid flow rate control valve 55B, and is supplied to the central region of the underside of the substrate W.
By using the wet processing unit 2W shown in FIG. 21 to supply a heating fluid to the underside of the substrate W in the polymer film heating process (step S6), the polymer film 101 on the upper surface of the substrate W can be heated through the substrate W.

The heating fluid discharged from the heating fluid nozzle 13 is, for example, high-temperature DIW having a temperature higher than room temperature and lower than the boiling point of the solvent of the polymer-containing liquid. The heating fluid discharged from the heating fluid nozzle 13 is not limited to high-temperature DIW, and may be a high-temperature gas such as a high-temperature inert gas or high-temperature air.
The substrate processing apparatus 1 equipped with the wet processing unit 2W shown in FIG. 21 can perform the substrate processing shown in FIG. 5, and can also perform each of the modified examples of the substrate processing (Modified Example 1 to Modified Example 6).

When the substrate processing shown in FIG. 14 is performed by a substrate processing apparatus 1 equipped with a wet processing unit 2W shown in FIG. 21, it is also possible to oxidize the layer to be processed to form an oxide layer by supplying a heated fluid to the underside of the substrate W (oxidation layer formation process). In this way, the heated fluid nozzle 13 functions as a substrate oxidation unit. By oxidizing the layer to be processed (the surface layer of the upper surface of the substrate W), a substrate W having an upper surface on which an oxide layer is exposed is prepared (substrate preparation process).

When performing the heating oxidation process (step S11) using the wet processing unit 2W shown in FIG. 21, it is preferable to adjust the temperature of the heating fluid when forming the oxidation layer so that the temperature of the heating fluid is higher than the temperature of the heating fluid when heating the polymer film 101.
<Modifications of opposing members provided in wet processing unit>
22 is a schematic diagram for explaining a modified example of the facing member 8. The facing member 8 shown in FIG. 22 has a treatment fluid storage space 27 for storing the treatment fluid discharged from the discharge port 12a of the treatment fluid nozzle 12.

22 is provided with a plurality of discharge ports 8b. The plurality of discharge ports 8b open from the facing surface 8a and are provided at equal intervals across the entire facing surface 8a. The plurality of discharge ports 8b are connected to the treatment fluid storage space 27 and discharge the treatment fluid in the treatment fluid storage space 27.
Since the multiple discharge ports 8b are provided at equal intervals on the facing surface 8a, the processing fluid can be easily supplied evenly to the entire space SP1 between the upper surface of the substrate W and the facing surface 8a in the processing fluid supplying step (step S7), which makes it easy to maintain the humidity at each position in the space SP1 uniform.

<Modifications of Processing Fluid Nozzle>
23 to 25 are schematic diagrams for explaining first to third modified examples of the processing fluid nozzle 12, respectively.
23 as a first modified example, the processing fluid nozzle 12 may be a movable nozzle that is not disposed within the facing member 8 and is movable in the horizontal direction along the upper surface of the substrate W. The processing fluid nozzle 12 is moved in the horizontal direction by a third nozzle moving mechanism 35 having a configuration similar to that of the first nozzle moving mechanism 33. The processing fluid nozzle 12 may be movable in the vertical direction.

The processing fluid nozzle 12 is connected to one end of a DIW supply pipe 43 that guides DIW to the processing fluid nozzle 12. The other end of the DIW supply pipe 43 is connected to a DIW tank (not shown). A humidification unit 36 and a humidity measurement unit 38 are attached to the processing fluid nozzle 12. The processing fluid nozzle 12 has an outlet 12a that discharges the processing fluid, and a supply section 12b (supply path 37) that forms a flow path that sends the processing fluid whose humidity has been adjusted by the humidification unit 36 to the outlet 12a.

The DIW supply pipe 43 shown in FIG. 23 is provided with a DIW valve 53A that opens and closes the flow path in the DIW supply pipe 43, and a DIW flow rate adjustment valve 53B that adjusts the flow rate of the liquid DIW in the flow path. When the DIW valve 53A is opened, the liquid DIW is supplied to the humidification unit 36 at a flow rate that corresponds to the opening degree of the DIW flow rate adjustment valve 53B. The humidification unit 36 forms a processing fluid from the liquid DIW. The processing fluid formed by the humidification unit 36 is discharged from the discharge port 12a of the processing fluid nozzle 12.

In the treatment fluid supply step (step S7), the treatment fluid nozzle 12 is moved along the upper surface of the substrate W while discharging the treatment fluid from the treatment fluid nozzle 12 toward the space SP2 in contact with the polymer film 101 on the upper surface of the substrate W. Specifically, the treatment fluid nozzle 12 discharges the treatment fluid toward the space SP2 in contact with the polymer film 101 while moving between a central position (see solid line in FIG. 23) facing the central region of the upper surface of the substrate W and a peripheral position (see dashed double-dashed line in FIG. 23) facing the peripheral region of the upper surface of the substrate W. Therefore, the treatment fluid can be supplied quickly to the entire polymer film 101 on the upper surface of the substrate W, compared to the case where the treatment fluid is supplied toward only a part of the space SP2 in contact with the upper surface of the substrate W.

According to the configuration shown in FIG. 23, the humidity of the processing fluid passing through the supply unit 12b can be adjusted by the humidification unit 36 based on the humidity measured by the humidity measurement unit 38. This allows the humidity of the processing fluid passing through the supply unit 12b, i.e., the humidity of the processing fluid discharged from the discharge port 12a of the processing fluid nozzle 12, to be adjusted to a desired humidity. As a result, the humidity of the atmosphere in contact with the polymer film 101 on the upper surface of the substrate W can be adjusted to a humidity that can effectively promote etching of the substrate W by the polymer film 101.

The humidity measurement unit 38 and the humidification unit 36 do not necessarily have to be attached to the treatment fluid nozzle 12. In more detail, as shown in FIG. 24 as a second modified example, the humidification unit 36 may be connected to a treatment fluid pipe 44 that supplies treatment fluid to the treatment fluid nozzle 12, and the humidity measurement unit 38 may be attached to the treatment fluid pipe 44. In the configuration shown in FIG. 24, the supply section 12b of the treatment fluid nozzle 12 and the treatment fluid pipe 44 form a supply path 37. The configuration shown in FIG. 24 also provides the same effect as the configuration shown in FIG. 23.

In the configuration shown in FIG. 24, the humidity measurement unit 38 and the humidification unit 36 can be arranged outside the chamber 4. For example, if there is not enough space to arrange the humidity measurement unit 38 and the humidification unit 36 inside the chamber 4, the space outside the chamber 4 can be effectively utilized by arranging the humidity measurement unit 38 and the humidification unit 36 outside the chamber 4.

25 as a third modified example, the processing fluid nozzle 12 may be configured to eject processing fluid both downward and horizontally. Specifically, the processing fluid nozzle 12 includes a nozzle body 152 having a bottom surface (lower surface) 150 and a substantially cylindrical side surface 151 connected to the bottom surface 150 and extending vertically. The processing fluid nozzle 12 includes a first ejection port 150a that is circular in plan view and opens from the bottom surface 150 and ejects processing fluid linearly downward, and a second ejection port 150b that is annular and opens from the side surface 151 and ejects gas radially outward from the side surface 151.

A first flow passage 152a for supplying the processing fluid to the first outlet 150a and a second flow passage 152b for supplying the processing fluid to the second outlet 150b are formed inside the nozzle body 152.
The wet processing unit 2W includes a first processing fluid pipe 44A connected to the nozzle body 152 and supplying processing fluid to a first flow path 152a of the nozzle body 152, a second processing fluid pipe 44B connected to the nozzle body 152 and supplying processing fluid to a second flow path 152b of the nozzle body 152, a first humidity measuring unit 38A attached to the first processing fluid pipe 44A, and a second humidity measuring unit 38B attached to the second processing fluid pipe 44B.

The wet processing unit 2W includes a first humidification unit 36A connected to the first processing fluid pipe 44A and adjusting the humidity of the processing fluid, a first DIW supply pipe 43A that sends liquid DIW from a DIW supply source (not shown) to the first humidification unit 36A, a second humidification unit 36B connected to the second processing fluid pipe 44B and adjusting the humidity of the processing fluid, and a second DIW supply pipe 43B that sends liquid DIW from a DIW supply source (not shown) to the second humidification unit 36B.

A DIW valve 53A and a DIW flow rate adjustment valve 53B are provided in each of the DIW supply pipes (the first DIW supply pipe 43A and the second DIW supply pipe 43B).
25, a supply path 37 for supplying the processing fluid to the first outlet 150a and the second outlet 150b is formed by a nozzle body 152, a first processing fluid pipe 44A, and a second processing fluid pipe 44B. The processing fluid path formed by the nozzle body 152 and the first processing fluid pipe 44A is referred to as a first supply path for supplying the processing fluid to the first outlet 150a. Similarly, the processing fluid path formed by the nozzle body 152 and the second processing fluid pipe 44B is referred to as a second supply path for supplying the processing fluid to the second outlet 150b.

In the third modified example shown in FIG. 25, a separate humidification unit is provided for each treatment liquid supply pipe, but the first treatment fluid pipe 44A and the second treatment fluid pipe 44B may be connected to a single humidification unit. Also, in the third modified example, a separate humidity measurement unit is attached to each treatment fluid pipe, but a single humidity measurement unit may be attached across both the first treatment fluid pipe 44A and the second treatment fluid pipe 44B.

<Configuration of the Substrate Processing Apparatus According to the Second Embodiment>
FIG. 26 is a plan view for illustrating the configuration of a substrate processing apparatus 1P according to the second embodiment.
The substrate processing apparatus 1P according to the second embodiment differs from the substrate processing apparatus 1 according to the first embodiment (see FIG. 2A) mainly in that the processing unit 2 includes a wet processing unit 2W and a dry processing unit 2D.

26, the same components as those shown in the above-mentioned Figures 1 to 25 are denoted by the same reference numerals as in Figure 1, etc., and the description thereof will be omitted. The same applies to Figures 27 to 30 described later.
In the dry processing unit 2D, a dry oxidation process is carried out to form an oxide layer 103 by at least one of light irradiation, heating, and supply of a gaseous oxidizing agent.

In the example shown in Figure 26, the two processing towers on the side of the transport robot IR are composed of a plurality of wet processing units 2W, and the two processing towers on the opposite side of the transport robot IR are composed of a plurality of dry processing units 2D.
The configuration of the wet processing unit 2W according to the second embodiment is the same as that of the wet processing unit 2W according to the first embodiment (the configuration shown in FIG. 3, and FIGS. 21 to 25). Note that in the wet processing unit 2W according to the second embodiment, the oxidizer nozzle 9 (see FIG. 3, etc.) can be omitted. The dry processing unit 2D is disposed in the chamber 4, and includes a light irradiation processing unit 70 that performs light irradiation processing on the substrate W.

A configuration example of the light irradiation processing unit 70 will be described below. Fig. 27 is a schematic cross-sectional view for explaining a configuration example of the light irradiation processing unit 70.
The light irradiation processing unit 70 comprises a base 72 having a mounting surface 72a on which the substrate W is placed, a light processing chamber 71 that houses the base 72, a light irradiation unit 73 that irradiates light such as ultraviolet light toward the upper surface of the substrate W placed on the mounting surface 72a, a plurality of lift pins 75 that move up and down through the base 72, and a pin lifting mechanism 76 that moves the multiple lift pins 75 up and down.

A loading/unloading opening 71a for the substrate W is provided on the side wall of the optical processing chamber 71, and the optical processing chamber 71 has a gate valve 71b that opens and closes the loading/unloading opening 71a. When the loading/unloading opening 71a is open, the hand H of the transport robot CR can access the optical processing chamber 71. The substrate W is placed on the base 72 and held horizontally at a predetermined holding position. The predetermined holding position is the position of the substrate W shown in FIG. 27, where the substrate W is held in a horizontal position.

The light irradiation unit 73 includes, for example, a plurality of light irradiation lamps. The light irradiation lamps are, for example, xenon lamps, mercury lamps, deuterium lamps, etc. The light irradiation unit 73 is configured to irradiate, for example, ultraviolet light of 1 nm or more and 400 nm or less, preferably 1 nm or more and 300 nm or less. Specifically, a current supply unit 74 such as a power supply is connected to the light irradiation unit 73, and the light irradiation unit 73 (the light irradiation lamp) irradiates light by supplying power from the current supply unit 74. For example, the light irradiation generates ozone in the atmosphere in contact with the main surface of the substrate W, and the upper surface of the substrate W is oxidized by the ozone.

The lift pins 75 are inserted into a number of through holes 78 that penetrate the base 72 and the light processing chamber 71. The lift pins 75 are connected by a connecting plate 77. The pin lifting mechanism 76 raises and lowers the connecting plate 77, so that the lift pins 75 are moved up and down between an upper position (position shown by a two-dot chain line in FIG. 27) where the substrate W is supported above the mounting surface 72a, and a lower position (position shown by a solid line in FIG. 27) where the tip (upper end) is recessed below the mounting surface 72a. The pin lifting mechanism 76 may have an electric motor or an air cylinder, or may have an actuator other than these.

As indicated by the two-dot chain line in FIG. 4, each member included in the dry processing unit 2D is also controlled by the controller 3, similarly to the wet processing unit 2W.
<Example of Substrate Processing According to Second Embodiment>
28 is a flow chart for explaining an example of the substrate processing performed by the substrate processing apparatus 1P according to the second embodiment. The substrate processing according to the second embodiment differs from the substrate processing according to the first embodiment (see FIG. 5) mainly in that an oxide layer is formed by the dry processing unit 2D and the oxide layer is removed by the wet processing unit 2W.

Hereinafter, differences between the substrate processing according to the second embodiment and the substrate processing according to the first embodiment (see FIG. 5) will be described in detail, mainly with reference to FIGS. 3, 27 and 28.
First, an unprocessed substrate W is carried from the carrier C into the dry processing unit 2D by the transport robots IR, CR (see also FIG. 26 ) and handed over to the lift pins 75 located at the upper position (first carrying-in step: step S20). The pin lifting mechanism 76 moves the lift pins 75 to the lower position, so that the substrate W is placed on the placement surface 72a. This allows the substrate W to be held horizontally (first substrate holding step).

Next, after the transport robot CR retreats from the dry processing unit 2D, a light irradiation process (step S21) is performed in which light is irradiated onto the upper surface of the substrate W to form an oxide layer. Specifically, the power supply unit 74 supplies power to the light irradiation unit 73. This causes the light irradiation unit 73 to start irradiating the substrate W with light. The light irradiation oxidizes the processing target layer exposed from the upper surface of the substrate W, forming an oxide layer (oxidation layer formation process, light irradiation process, dry oxidation process). By oxidizing the processing target layer (the surface layer of the upper surface of the substrate W), a substrate W having an upper surface on which an oxide layer is exposed is prepared (substrate preparation process).

The oxide layer formed by the light irradiation has a thickness of 10 nm to 20 nm. The light irradiation unit 73 functions as a substrate oxidation unit.
After a certain period of light irradiation, the transport robot CR enters the dry processing unit 2D, receives the oxidized substrate W from the base 72, and carries it out of the dry processing unit 2D (first carrying-out step: step S22). Specifically, the pin lifting mechanism 76 moves the multiple lift pins 75 to an upper position, and the multiple lift pins 75 lift the substrate W from the base 72. The transport robot CR receives the substrate W from the multiple lift pins 75.

The substrate W unloaded from the dry processing unit 2D is loaded into the wet processing unit 2W by the transport robot CR and handed over to the multiple chuck pins 20 (see FIG. 3) of the spin chuck 5 (second loading process: step S23). The opening/closing mechanism 25 (see FIG. 3) moves the multiple chuck pins 20 to the closed position, whereby the substrate W is gripped by the multiple chuck pins 20. As a result, the substrate W is held horizontally by the spin chuck 5 (see FIG. 3) (second substrate holding process). With the substrate W held by the spin chuck 5, the spin motor 23 (see FIG. 3) starts rotating the substrate W (substrate rotation process).

Thereafter, as shown in Figures 6C to 6H, a polymer-containing liquid supplying process (step S4), a polymer film forming process (step S5), a polymer film heating process (step S6), a treatment fluid supplying process (step S7), and a polymer film removing process (step S8) are carried out.
After the polymer film removal process, a spin dry process (step S9) is performed. Specifically, the rinse liquid valve 52A is closed to stop the supply of the rinse liquid to the upper surface of the substrate W. Then, the spin motor 23 accelerates the rotation of the substrate W to rotate the substrate W at high speed. The substrate W is rotated at a drying speed, for example, 1500 rpm. As a result, a large centrifugal force acts on the rinse liquid on the substrate W, and the rinse liquid on the substrate W is spun off around the substrate W.

Then, the spin motor 23 stops the rotation of the substrate W. The transport robot CR enters the wet processing unit 2W, receives the substrate W from the multiple chuck pins 20, and unloads the substrate W from the wet processing unit 2W (second unloading step: step S24).
According to the second embodiment, similarly to the first embodiment, the substrate W is etched by the acidic polymer contained in the polymer film 101 formed on the upper surface of the substrate W. Therefore, the amount of the substance (hydrofluoric acid or acidic polymer) required for etching the processing target layer 102 can be reduced.

According to the second embodiment, the following effects are further achieved. For example, according to the second embodiment, the processing target layer 102 is oxidized by light irradiation. That is, the substrate W can be oxidized without using a liquid oxidizing agent. This eliminates the need to remove the liquid oxidizing agent adhering to the upper surface of the substrate W. In addition, since the substrate W is oxidized by light irradiation, the processing target layer 102 can be etched without using an oxidizing agent. That is, the amount of material required to etch the processing target layer 102 can be reduced.

As shown by the two-dot chain line in FIG. 28, the cycle process, in which the first carry-in process (step S20) to the second carry-out process (step S24) constitute one cycle, may be performed one or more times. That is, the cycle process may be performed multiple times. After the final second carry-out process (step S24), the substrate W is handed over from the transport robot CR to the transport robot IR, and is stored in the carrier C by the transport robot IR. By performing the cycle process, the formation of the oxide layer 103 and the removal of the oxide layer 103 are alternately repeated, so that the layer to be processed 102 can be etched with high precision.

Unlike the substrate processing shown by the two-dot chain line in FIG. 28, the spin dry steps other than the final spin dry step (step S9) may be omitted. In particular, except for after the final polymer film removal step (step S8), the substrate W may be transported from the wet processing unit 2W to the dry processing unit 2D without performing a spin dry step after the polymer film removal step.

<Modification of Dry Processing Unit>
The dry processing unit 2D may include a gas oxidation processing unit 80 instead of the light irradiation processing unit 70. Figure 29 is a schematic cross-sectional view for explaining an example of the configuration of the gas oxidation processing unit 80.
The gas oxidation treatment unit 80 includes a heater unit 82 having a heating surface 82 a on which a substrate W is placed, and a heat treatment chamber 81 accommodating the heater unit 82 .

The heater unit 82 has the form of a disk-shaped hot plate and includes a plate body 82A and a heater 85. The heater unit 82 is also referred to as a heating member.
The upper surface of the plate body 82A constitutes the heating surface 82a. The heater 85 may be a resistor built into the plate body 82A. The heater 85 can heat the substrate W to a temperature substantially equal to the temperature of the heater 85. The heater 85 is configured to heat the substrate W placed on the heating surface 82a to a predetermined temperature range of, for example, room temperature or higher and 400° C. or lower. Specifically, a current supply unit 86 such as a power source is connected to the heater 85, and the temperature of the heater 85 changes to a temperature within the predetermined temperature range by adjusting the current supplied from the current supply unit 86.

The heat treatment chamber 81 comprises a chamber body 87 that opens upward, and a lid 88 that moves up and down above the chamber body 87 to close the opening of the chamber body 87. The gas oxidation treatment unit 80 comprises a lid lifting mechanism 89 that lifts and lowers (moves up and down) the lid 88. The gap between the chamber body 87 and the lid 88 is sealed by an elastic member 90 such as an O-ring.
The lid 88 is moved up and down by a lid lifting mechanism 89 between a lower position (position shown by solid lines in Figure 29) in which it closes the opening of the chamber body 87 to form a sealed processing space SP3 inside, and an upper position (position shown by dotted lines in Figure 29) in which it is retracted upward to open the opening.

When the lid 88 is in the upper position, the hand H of the transport robot CR can access the inside of the heat treatment chamber 81. The substrate W is placed on the heater unit 82 and held horizontally at a predetermined holding position. The predetermined holding position is the position of the substrate W shown in FIG. 29, where the substrate W is held in a horizontal attitude.
The lid lifting mechanism 89 may have an electric motor or an air cylinder, or may have an actuator other than these.

The gas oxidation treatment unit 80 further includes a plurality of lift pins 83 that move up and down through the plate body 82A, and a pin lifting mechanism 84 that moves the plurality of lift pins 83 in the vertical direction. The plurality of lift pins 83 are connected by a connecting plate 91. The pin lifting mechanism 84 raises and lowers the connecting plate 91, so that the plurality of lift pins 83 are moved up and down between an upper position (position shown by a two-dot chain line in FIG. 29) where the substrate W is supported above the heating surface 82a, and a lower position (position shown by a solid line in FIG. 29) where the tip (upper end) is immersed below the heating surface 82a. The pin lifting mechanism 84 may be an electric motor or an air cylinder, or may be an actuator other than these.

The multiple lift pins 83 are inserted into multiple through holes 92 that penetrate the heater unit 82 and the chamber body 87. Entry of fluid from outside the heat treatment chamber 81 into the through holes 92 may be prevented by a bellows (not shown) or the like that surrounds the lift pins 83.
The gas oxidation treatment unit 80 is provided with a plurality of gas introduction ports 94 for introducing a gaseous oxidizing agent into the sealed treatment space SP3 in the heat treatment chamber 81. Each gas introduction port 94 is a through-hole penetrating the lid 88.

The gaseous oxidizing agent is a gas that forms an oxide layer by oxidizing a processing target layer exposed from the substrate W. The gaseous oxidizing agent is, for example, ozone (O ₃ ) gas. The gaseous oxidizing agent is not limited to ozone gas, and may be, for example, oxidizing water vapor, superheated water vapor, or the like.
A gaseous oxidizer pipe 95 that supplies a gaseous oxidizer to the gas inlet ports 94 is connected to the multiple gas inlet ports 94. The gaseous oxidizer pipe 95 branches on the way from a gaseous oxidizer supply source (not shown) to the multiple gas inlet ports 94. A gaseous oxidizer valve 96A that opens and closes the flow path of the gaseous oxidizer pipe 95 and a gaseous oxidizer flow rate adjustment valve 96B that adjusts the flow rate of the gaseous oxidizer in the gaseous oxidizer pipe 95 are interposed in the gaseous oxidizer pipe 95.

When the gaseous oxidant valve 96A is opened, a gaseous oxidant is introduced into the sealed processing space SP3 from the multiple gas inlet ports 94, and the gaseous oxidant is supplied toward the upper surface of the substrate W. The multiple gas inlet ports 94 are an example of a gaseous oxidant supplying member.
The gas introduction ports 94 may be configured to supply an inert gas in addition to the gaseous oxidizing agent (see the two-dot chain line in FIG. 29). Also, the gaseous oxidizing agent introduced into the sealed processing space SP3 can be mixed with the inert gas, and the concentration (partial pressure) of the oxidizing agent can be adjusted by the degree of mixing of the inert gas.

The gas oxidation treatment unit 80 is provided with a plurality of exhaust ports 97 formed in the chamber body 87 for exhausting the internal atmosphere of the heat treatment chamber 81. Each exhaust port 97 is connected to an exhaust pipe 98, and the exhaust pipe 98 is provided with an exhaust valve 99 for opening and closing the flow path.
<Another Example of Substrate Processing According to the Second Embodiment>
FIG. 30 is a flow chart illustrating another example of the substrate processing according to the second embodiment.
The substrate processing shown in Figure 30 differs from the substrate processing shown in Figure 28 in that, instead of the light irradiation process (step S21), a gaseous oxidant supply process (step S30) is performed in which a gaseous oxidant is supplied toward the upper surface of the substrate W while heating the substrate W, thereby forming an oxide layer.

3, 29 and 30, the substrate processing shown in FIG. 30 will be described, focusing on the differences from the substrate processing shown in FIG.
First, an unprocessed substrate W is carried from the carrier C into the dry processing unit 2D by the transport robots IR, CR (see also FIG. 26) (first carrying-in step: step S20). The pin lifting mechanism 84 moves the lift pins 83 to a lower position, so that the substrate W is placed on the heating surface 82a. This allows the substrate W to be held horizontally (first substrate holding step).

Then, the lid 88 is lowered, so that the substrate W is placed on the heating surface 82a of the heater unit 82 within the sealed processing space SP3 formed by the chamber body 87 and the lid 88. The substrate W placed on the heating surface 82a is heated to a predetermined oxidation temperature by the heater unit 82 (substrate heating process, heater heating process). The predetermined oxidation temperature is, for example, a temperature of 100°C or higher and 400°C or lower.

With the sealed processing space SP3 formed, the gaseous oxidizer valve 96A is opened, whereby a gaseous oxidizer such as ozone gas is introduced into the sealed processing space SP3 from the multiple gas inlet ports 94, and the gaseous oxidizer is supplied toward above the substrate W (gaseous oxidizer supply step: step S30).
Before the gaseous oxidizing agent is supplied to the sealed processing space SP3, an inert gas may be supplied to the sealed processing space SP3 from the gas introduction port 94 to replace the atmosphere in the sealed processing space SP3 with the inert gas (pre-replacement process).

The gaseous oxidizing agent discharged from the multiple gas introduction ports 94 oxidizes the exposed layer to be treated from the substrate W to form an oxide layer (oxidation layer forming step, gaseous oxidizing agent supply step, dry oxidation step). The layer to be treated (the surface layer of the upper surface of the substrate W) is oxidized to prepare a substrate W having an upper surface on which an oxide layer is exposed (substrate preparation step).
The oxide layer formed by the gaseous oxidizing agent such as ozone gas has a thickness of, for example, 10 nm or more and 20 nm or less. The substrate W is heated to an oxidation temperature on the heater unit 82. Therefore, in the oxide layer forming step, a heating and oxidation step is performed in which a gaseous oxidizing agent is supplied toward the upper surface of the substrate W while the substrate W is heated to the oxidation temperature. In this way, the gas introduction port 94 and the heater unit 82 function as a substrate oxidation unit.

During the supply of the gaseous oxidizing agent, the exhaust valve 99 is opened so that the gaseous oxidizing agent in the sealed processing space SP3 is exhausted through the exhaust pipe 98.
After the upper surface of the substrate W is treated with the gaseous oxidizing agent, the gaseous oxidizing agent valve 96A is closed. This stops the supply of the gaseous oxidizing agent to the sealed processing space SP3. Then, the lid 88 is moved to the upper position. The lid 88 may be moved to the upper position after the atmosphere in the sealed processing space SP3 is replaced with an inert gas.

After a certain period of heat treatment, the transport robot CR enters the dry processing unit 2D and transports the oxidized substrate W out of the dry processing unit 2D (first transport step: step S22). Specifically, the pin lifting mechanism 84 moves the multiple lift pins 83 to the upper position, and the multiple lift pins 83 lift the substrate W from the heater unit 82. The transport robot CR receives the substrate W from the multiple lift pins 83. The substrate W transported out of the dry processing unit 2D is transported by the transport robot CR into the wet processing unit 2W and handed over to the multiple chuck pins 20 (see FIG. 3) of the spin chuck 5 (second transport step: step S23).

30, the oxide layer 103 can be formed without using a liquid oxidizing agent. This eliminates the need to remove the liquid oxidizing agent attached to the upper surface of the substrate W.
As shown by the two-dot chain line in Fig. 30, the cycle process, in which the first carry-in step (step S20) to the second carry-out step (step S24) constitute one cycle, may be performed one or more times. That is, the cycle process may be performed multiple times. After the final second carry-out step (step S24), the substrate W is handed over from the transport robot CR to the transport robot IR, and is stored in the carrier C by the transport robot IR. By performing the cycle process, the formation of the oxide layer 103 and the removal of the oxide layer 103 are alternately repeated, so that the processing target layer 102 can be etched with high precision.

The oxide layer 103 may be formed by only supplying a gaseous oxidizing agent or only heating the substrate W using the dry processing unit 2D shown in Fig. 29. Also, the dry processing unit 2D shown in Fig. 27 and the dry processing unit 2D shown in Fig. 29 may be combined.
For example, the oxide layer 103 may be formed by heating the substrate W while irradiating the substrate W with light. Specifically, the ultraviolet radical oxidation process can be performed by heating the substrate W while irradiating the substrate W with ultraviolet light. The oxide layer 103 may also be formed by supplying a gaseous oxidizing agent to the substrate W while irradiating the substrate W with light. The layer to be treated of the substrate W may also be oxidized by heating the substrate W while irradiating the substrate W with ultraviolet light and supplying a gaseous oxidizing agent.

In other words, the dry processing unit 2D can be not only the dry processing unit 2D shown in Figures 27 and 29, but also any dry processing unit that can form an oxide layer 103 by at least one of light irradiation, supply of a gaseous oxidizing agent, and heating of the substrate W.
<Etching experiment results>
31A to 31C are schematic diagrams for explaining the processing procedure of an etching experiment for observing the change in the amount of etching due to differences in processing procedures.

Figure 31A is a schematic diagram for explaining a first processing procedure in which a substrate is etched with a liquid film of a polymer-containing liquid. Figure 31B is a schematic diagram for explaining a second processing procedure in which a substrate is etched with a polymer film. In the second processing method shown in Figure 31B, no processing fluid is supplied. Figure 31C is a schematic diagram for explaining a third processing procedure in which a substrate is etched with a polymer film supplied with a processing fluid.

The substrate used in each process is a small rectangular substrate (small substrate) with each side measuring 3 cm when viewed from the normal direction of the main surface, and the copper layer is exposed from the main surface of the small substrate. The polymer-containing liquid used in each process is a liquid obtained by neutralizing an aqueous solution of an acidic polymer by adding ammonia water (pH = 7.0).
Referring to FIG. 31A, the first processing procedure is as follows.

(a) First, the small substrate piece 200 was placed on a rotatable heater 201 and heated to 180° C. to form an oxide layer on the surface layer of the main surface of the small substrate piece 200 .
(b) The small substrate piece 200 was placed on a rotatable spin coater 204, and while rotating the spin coater 204 at 1500 rpm, the polymer-containing liquid was supplied onto the main surface of the small substrate piece 200 to form a liquid film 202 of the polymer-containing liquid. Thereafter, the state in which the liquid film 202 was formed was maintained for 5 minutes.

(c) After that, DIW was supplied to the main surface of the small substrate piece 200 for 30 seconds to remove the polymer-containing liquid from the small substrate piece 200 .
(d) After that, the spin coater 204 was rotated to rotate the substrate piece 200, thereby drying the substrate piece 200.
(e) After the small substrate piece 200 was dried, the thickness of the copper layer of the small substrate piece 200 was confirmed using a scanning electron microscope (SEM).

Referring to FIG. 31B, the second processing procedure is as follows.
(a) First, the small substrate piece 200 was placed on a heater 201 and heated to 180° C. to form an oxide layer on the surface layer of the main surface of the small substrate piece 200 .
(b) While rotating the spin coater 204 at 1500 rpm, the polymer-containing liquid was supplied onto the main surface of the substrate piece 200. After the supply of the polymer-containing liquid, the rotation of the spin coater 204 at 1500 rpm was maintained for 30 seconds to form a polymer film 203 on the main surface of the substrate piece 200.

(c) After that, the small substrate piece 200 was placed on the heater 201, and the small substrate piece 200 was heated by the heater 201 at 60° C. for 60 seconds.
(d) After heating by the heater 201 was stopped, the substrate piece was left standing for 60 seconds.
(e) After that, the small substrate piece 200 was placed on a spin coater 204 , and DIW was supplied to the main surface of the small substrate piece 200 for 30 seconds to remove the polymer-containing liquid from the small substrate piece 200 .

(f) Then, (b) through (e) were performed four more times (for a total of five times).
(g) After that, the spin coater 204 was rotated to rotate the substrate piece 200, thereby drying the substrate piece 200.
(h) After the small substrate piece 200 was dried, the thickness of the copper layer of the small substrate piece 200 was confirmed using an SEM.

Referring to FIG. 31C, the third processing procedure is as follows.
(a) First, the small substrate piece 200 was placed on a heater 201 and heated to 180° C. to form an oxide layer on the surface layer of the main surface of the small substrate piece 200 .
(b) The small substrate piece 200 was placed on a rotatable spin coater 204, and while rotating the spin coater 204 at 1500 rpm, a polymer-containing liquid was supplied onto the main surface of the small substrate piece 200. After the supply of the polymer-containing liquid, the rotation of the spin coater 204 at 1500 rpm was maintained for 30 seconds, thereby forming a polymer film 203 on the main surface of the small substrate piece 200.

(c) After that, the small substrate piece 200 was placed on the heater 201, and the small substrate piece 200 was heated by the heater 201 at 60° C. for 60 seconds.
(d) After the heating by the heater 201 was stopped, the small substrate 200 was placed on a spin coater 204, and a processing fluid (water vapor) having a predetermined humidity was supplied for 60 seconds to the main surface of the small substrate 200. The humidity of the processing fluid supplied to the main surface of the small substrate 200 was approximately 100%, or 80% or more and 95% or less.

(e) After that, DIW was supplied to the main surface of the small substrate piece 200 for 30 seconds to remove the polymer-containing liquid from the substrate.
(f) (b) through (e) were then performed four or nine more times (for a total of five or ten times).
(g) After that, the small substrate 200 was dried by rotating the small substrate 200 .

(h) After the small substrate piece 200 was dried, the thickness of the copper layer of the small substrate piece 200 was confirmed using an SEM.
Fig. 32 is a graph showing the results of an etching experiment. Fig. 32 shows the thickness of the copper layer of the small substrate 200 when the main surface is oxidized and no etching is performed as a reference example. In Fig. 32, the thickness of the copper layer of the small substrate 200 of the reference example is used as a reference, and the thickness of the small substrate 200 after etching in each processing step is shown as a ratio to the thickness of the copper layer of the small substrate 200 of the reference example.

In FIG. 32, "Third Processing Procedure (5 times, 100%)" indicates that the steps (b) to (e) in FIG. 31C were performed 5 times in the third processing procedure, and the humidity of the processing fluid used at that time was nearly 100%. Similarly, "Third Processing Procedure (10 times, 100%)" indicates that the steps (b) to (e) in FIG. 31C were performed 10 times in the third processing procedure, and the humidity of the processing fluid used at that time was nearly 100%. "Third Processing Procedure (5 times, 80% to 95%)" indicates that the steps (b) to (e) in FIG. 31C were performed 5 times in the third processing procedure, and the humidity of the processing fluid used at that time was 80% or more and 95% or less.

When the small piece substrate 200 was etched in the first processing procedure using a liquid film of a polymer-containing liquid, no significant change was observed in the thickness of the copper layer compared to the small piece substrate 200 of the reference example in which etching was not performed after the small piece substrate 200 was oxidized. Similarly, when the small piece substrate 200 was etched in the second processing procedure using the polymer film 203, no significant change was observed in the thickness of the copper layer compared to the small piece substrate 200 of the reference example.

On the other hand, when the small substrate 200 was etched in the third processing procedure using the polymer film 203, the thickness of the copper layer of the small substrate 200 was clearly smaller than that of the small substrate 200 of the reference example under all conditions. This resulted in the conclusion that the formation of the polymer film 203 promotes the etching of the small substrate 200.
Furthermore, when the small substrate 200 was etched in the third processing procedure using the polymer film 203, the thickness of the copper layer of the small substrate 200 was smaller under all conditions than when the small substrate 200 was etched in the second processing procedure. This resulted in the etching of the small substrate 200 being promoted by the supply of the processing fluid.

In the above etching experiment, when the small piece substrate 200 was etched using the second processing procedure, the result was that the thickness of the small piece substrate 200 was almost the same as in the reference example. However, this result does not deny the etching of the substrate when no processing fluid is supplied, nor does it mean that etching by the polymer film 203 does not occur when no processing fluid is supplied. In other words, although no significant etching progress was observed in this experiment, etching of the small piece substrate 200 can be observed by changing the experimental conditions slightly, for example, the heating time and the subsequent leaving time.

<Other embodiments>
The present invention is not limited to the above-described embodiment, and can be embodied in other forms.
In the above embodiment, the polymer-containing liquid contains an acidic polymer and an alkaline component as a solute. However, it is also possible to use a polymer-containing liquid that does not contain an alkaline component as a solute.

For example, in the substrate processing of the first embodiment shown in Figures 5 to 6H, even if a polymer-containing liquid that does not contain an alkaline component is used, the substrate W can be etched. Similarly, the substrate processing modifications shown in Figures 12, 14, 16, and 18 to 20 can be performed using a polymer-containing liquid that does not contain an alkaline component, and the substrate processing of the second embodiment shown in Figures 28 and 30 can also be performed.

When a polymer-containing liquid that does not contain an alkaline component is used, etching of the substrate W is initiated by the action of the acidic polymer in the polymer-containing liquid or the polymer film 101. Therefore, etching of the oxide layer 103 may be initiated at the start of the polymer-containing liquid on the upper surface of the substrate W (polymer-containing liquid supplying step) or at the formation of the polymer film 101 (polymer film forming step). In this case, etching of the substrate W may be promoted by heating the polymer film 101 in the polymer film heating step (step S6). Alternatively, etching of the substrate W may be initiated by heating the polymer film 101 in the polymer film heating step (step S6), or etching of the substrate W may be initiated by supplying a processing fluid to the polymer film 101 in the processing fluid supplying step (step S7).

In the third modified example of the substrate processing shown in FIG. 16, the polymer film 101 is not heated from when the polymer film 101 is formed until when the polymer film 101 is removed. Therefore, since it may take a long time to remove the alkaline component from the polymer film 101, it is preferable to use a polymer-containing liquid that does not contain an alkaline component as a solute. In the fourth modified example of the substrate processing shown in FIG. 18, since the start of the polymer film 101 is not performed before the processing fluid supply process (step S7), it is also preferable to use a polymer-containing liquid that does not contain an alkaline component as a solute.

The polymer-containing liquid may contain other components as solutes in addition to the acidic polymer and the alkaline component. The polymer-containing liquid may also contain a conductive polymer such as polyacetylene as a solute. The conductive polymer is not limited to polyacetylene. The conductive polymer is a conjugated polymer having conjugated double bonds.
The conjugated polymer may be, for example, an aliphatic conjugated polymer such as polyacetylene, an aromatic conjugated polymer such as poly(p-phenylene), a mixed conjugated polymer such as poly(p-phenylenevinylene), a heterocyclic conjugated polymer such as polypyrrole, polythiophene, or poly(3,4-ethylenedioxythiophene) (PEDOT), a heteroatom-containing conjugated polymer such as polyaniline, a multi-chain conjugated polymer such as polyacene, a two-dimensional conjugated polymer such as graphene, or a mixture thereof. In other words, the conjugated polymer may include at least one of an aromatic conjugated polymer, a mixed conjugated polymer, a heterocyclic conjugated polymer, a multi-chain conjugated polymer, and a two-dimensional conjugated polymer.

If the polymer-containing liquid contains a conductive polymer, the polymer film formed in the polymer film formation process (step S4) will also contain a conductive polymer. The conductive polymer contained in the polymer film 101 can promote ionization of the acidic polymer in the polymer film 101. This allows the acidic polymer to act effectively on the oxide layer.

That is, the conductive polymer functions as a medium for the acidic polymer to release protons (hydrogen ions), similar to a solvent. Therefore, if the polymer film 101 contains a conductive polymer, even if the solvent has completely disappeared from the polymer film 101, the acidic polymer can be ionized and the ionized acidic polymer can act on the oxide layer 103. By supplying a processing fluid to the polymer film 101 containing a conductive polymer, etching of the substrate W can be further promoted.

Unlike the substrate processing shown in Fig. 12, after the polymer film removing step (step S8), the process may not return to the liquid oxidizing agent supplying step (step S2), but may return to the liquid oxidizing agent supplying step (step S2) after the spin drying step (step S9). The same applies to the substrate processing shown in Figs. 14, 16, 18, 19, and 20.
12, 14, 16, 18, 19, and 20, after the polymer film removal step (step S8) or the spin dry step (step S9), the process may return to the polymer film formation step (step S4) instead of returning to the liquid oxidizing agent supply step (step S2) or the oxidation heating step (step S11). By doing so, even if the oxide layer is not sufficiently removed by forming the polymer film 101 once, the oxide layer can be sufficiently removed by forming the polymer film 101 multiple times.

Similarly, in each substrate processing shown in FIG. 28 and FIG. 30, after the polymer film removal step (step S8) or the spin dry step (step S9), the process may return to the polymer film formation step (step S4) instead of proceeding to the second unloading step (step S24). By doing so, even if the oxide layer is not sufficiently removed by forming the polymer film 101 once, the oxide layer can be sufficiently removed by forming the polymer film 101 multiple times.

It is also possible to combine the various substrate processes. For example, the substrate process shown in FIG. 5 may be combined with the substrate process shown in FIG. 14. For example, the liquid oxidizing agent supply process (step S2) through the polymer film removal process (step S8) may be performed before the thermal oxidation process (step S10), or the liquid oxidizing agent supply process (step S2) may be performed after the thermal oxidation process (step S10) through the polymer film removal process (step S7).

In the above-described embodiment, the substrate processing including the oxide layer forming step and the oxide layer removing step is performed on the upper surface of the substrate W. However, unlike the above-described embodiment, the substrate processing may be performed on the lower surface of the substrate W.
In addition, the surface layer of the main surface of the substrate W used in the substrate processing according to the above-mentioned embodiment does not need to have the structure shown in Fig. 1. For example, the processing target layer 102 may be exposed from the entire main surface of the substrate W, or the uneven pattern 120 may not be formed. In addition, the processing target layer 102 does not need to be a metal layer, but may be a silicon oxide layer. In addition, the processing target layer 102 does not need to be composed of a single material, but may be composed of a plurality of materials.

The treatment fluid nozzle 12 is inserted into the opposing member 8 shown in Figures 3, 21, and 22. However, the treatment fluid nozzle 12 does not have to be provided. Specifically, in the configuration shown in Figure 3, the treatment fluid nozzle 12 may not be provided, and the treatment fluid in the treatment fluid pipe 44 may be discharged from the discharge port 8b through a flow path formed in the opposing member 8. In this case, the supply path 37 is formed by the opposing member 8 and the treatment fluid pipe 44 that is connected to the opposing member 8 and supplies the treatment fluid to the treatment fluid nozzle 12.

22, the processing fluid nozzle 12 may not be provided, and the processing fluid in the processing fluid pipe 44 may be supplied to the processing fluid storage space 27 through a flow path formed in the facing member 8. In this case, the supply path 37 is composed of the facing member 8 and the processing fluid pipe 44 that is connected to the facing member 8 and supplies the processing fluid to the processing fluid nozzle 12.

In the above-described embodiment, the substrate processing apparatus 1, 1P includes a transport robot IR, CR, a plurality of processing units 2, and a controller 3. However, the substrate processing apparatus 1, 1P may be configured with a single processing unit 2 and a controller 3, and may not include the transport robot IR, CR. Alternatively, the substrate processing apparatus 1, 1P may be configured with only a single processing unit 2. In other words, the processing unit 2 may be an example of a substrate processing apparatus.

In addition, in each of the above-described embodiments, some of the pipes, pumps, valves, actuators, etc. are omitted from the illustrations, but this does not mean that these components do not exist, and in reality, these components are provided in appropriate positions.
In the first embodiment, the substrate processing apparatus 1 includes transport robots IR and CR, a plurality of processing units 2, and a controller 3. However, the substrate processing apparatus 1 may be configured with a single processing unit 2 and a controller 3, and may not include the transport robots IR and CR. Alternatively, the substrate processing apparatus 1 may be configured with only a single processing unit 2. In other words, the processing unit 2 may be an example of a substrate processing apparatus.

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.
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.

Various other modifications may be made within the scope of the claims.

1: Substrate processing apparatus 1P: Substrate processing apparatus 2: Processing unit (substrate processing apparatus)
2W: Wet processing unit (substrate processing apparatus)
5: Spin chuck (substrate rotation unit)
6: Heater unit (heating unit)
8: opposing member 8a: opposing surface 8b: discharge port 10: polymer-containing liquid nozzle (polymer film forming unit)
11: Rinse liquid nozzle (rinse liquid supply unit)
12: Processing fluid nozzle (processing fluid supply unit)
36: Humidification unit 37: Supply path 38: Humidity measurement unit 101: Polymer film 102: Layer to be treated (surface layer of the main surface of the substrate)
103: Oxidized layer A1: Rotation axis SP1: Space (space between the opposing member and the main surface of the substrate, space in contact with the polymer film)
SP2: Space (space adjacent to polymer film)
W: Substrate

Claims (17)

a substrate preparation step of preparing a substrate having a main surface on which an oxide layer is exposed;
a polymer film forming step of forming a polymer film on the main surface of the substrate, the polymer film including an acidic polymer that dissolves and etches the oxide layer ;
a processing fluid supplying step of supplying a processing fluid containing at least one of a mist of a processing liquid having affinity for the acidic polymer and a vapor of the processing liquid to the polymer film formed on the main surface of the substrate;
a rinsing step of supplying a rinsing liquid toward the main surface of the substrate after the processing fluid supplying step ,
The method further includes a reforming step of forming an oxide layer by oxidizing a surface layer portion of the main surface of the substrate after the rinsing step,
A substrate processing method, comprising the steps of: after the rinsing step, the reforming step, the polymer film forming step, the processing fluid supplying step, and the rinsing step, each of which is performed at least once in this order . a substrate preparation step of preparing a substrate having a main surface on which an oxide layer is exposed;
a polymer film forming step of forming a polymer film on the main surface of the substrate, the polymer film including an acidic polymer that dissolves and etches the oxide layer;
a processing fluid supplying step of supplying a processing fluid containing at least one of a mist of a processing liquid having affinity for the acidic polymer and a vapor of the processing liquid to the polymer film formed on the main surface of the substrate;
a rinsing step of supplying a rinsing liquid toward the main surface of the substrate after the processing fluid supplying step,
The polymer film formed in the polymer film forming step further contains an alkaline component,
The substrate processing method further comprises a polymer film heating step of heating the polymer film before the processing fluid supply step is started. a substrate preparation step of preparing a substrate having a main surface on which an oxide layer is exposed;
a polymer film forming step of forming a polymer film on the main surface of the substrate, the polymer film including an acidic polymer that dissolves and etches the oxide layer;
a processing fluid supplying step of supplying a processing fluid containing at least one of a mist of a processing liquid having affinity for the acidic polymer and a vapor of the processing liquid to the polymer film formed on the main surface of the substrate;
a rinsing step of supplying a rinsing liquid toward the main surface of the substrate after the processing fluid supplying step,
The method for processing a substrate, wherein the processing liquid is water. The method of claim 3 , wherein the humidity of the processing fluid is greater than 50% and less than or equal to 100%. 4. The substrate processing method according to claim 3 , wherein the humidity of the processing fluid is not less than 80% and not more than 100%. 4. The method of claim 3 , wherein the humidity of the processing fluid is not less than 85% and not more than 95%. The method further includes a reforming step of forming an oxide layer by oxidizing a surface layer portion of the main surface of the substrate after the rinsing step,
The substrate processing method according to any one of claims 2 to 6 , wherein after the rinsing step, the reforming step, the polymer film forming step, the processing fluid supplying step, and the rinsing step are each performed at least once in this order. The substrate processing method according to claim 1 , wherein the substrate preparation step includes an oxide layer formation step of oxidizing a surface layer portion of the main surface of the substrate to form an oxide layer. The method further includes a polymer-containing liquid supplying step of supplying a polymer-containing liquid containing at least a solvent and the acidic polymer to a main surface of the substrate,
The substrate processing method according to claim 1 , wherein the polymer film forming step comprises the step of forming the polymer film by evaporating at least a part of a solvent in a polymer-containing liquid on the main surface of the substrate. The substrate processing method according to claim 9 , wherein the solvent is a liquid that is miscible with the processing liquid. The method further includes a step of disposing an opposing member having an opposing surface facing the main surface of the substrate and an outlet port opening in the opposing surface and outletting the processing fluid,
11. The substrate processing method according to claim 1, wherein the processing fluid supplying step includes a step of supplying the processing fluid to a space between the opposing surface and the main surface of the substrate by ejecting the processing fluid from the ejection port. The substrate processing method according to any one of claims 1 to 10, wherein the processing fluid supply step includes a step of discharging the processing fluid from the processing fluid nozzle toward a space on the main surface of the substrate that is in contact with the polymer film while moving the processing fluid nozzle along the main surface of the substrate. a polymer film forming unit for forming a polymer film on a main surface of a substrate having an exposed main surface on which an oxide layer is formed, the polymer film containing an acidic polymer that dissolves and etches the oxide layer ;
a processing fluid supply unit that supplies a processing fluid containing at least one of a mist of a processing liquid having affinity for the acidic polymer and a vapor of the processing liquid toward a main surface of the substrate;
a rinse liquid supply unit that supplies a rinse liquid toward the main surface of the substrate ,
The polymer film formed by the polymer film forming unit further contains an alkaline component,
The substrate processing apparatus further includes a heating unit configured to heat the polymer film through the substrate before the processing fluid supply unit supplies the processing fluid toward the main surface of the substrate . a polymer film forming unit for forming a polymer film on a main surface of a substrate having an exposed main surface on which an oxide layer is formed, the polymer film containing an acidic polymer that dissolves and etches the oxide layer;
a processing fluid supply unit that supplies a processing fluid containing at least one of a mist of a processing liquid having affinity for the acidic polymer and a vapor of the processing liquid toward a main surface of the substrate;
a rinse liquid supply unit that supplies a rinse liquid toward the main surface of the substrate,
the processing fluid supply unit includes an opposing member having an opposing surface facing the main surface of the substrate and a discharge port that opens in the opposing surface and discharges the processing fluid toward the main surface of the substrate,
The treatment liquid is water,
a humidification unit for adjusting the humidity of the processing fluid;
a supply path for supplying the processing fluid, the humidity of which has been adjusted by the humidification unit, to the discharge port;
a humidity measuring unit for measuring the humidity of the processing fluid passing through the supply path. a polymer film forming unit for forming a polymer film on a main surface of a substrate having an exposed main surface on which an oxide layer is formed, the polymer film containing an acidic polymer that dissolves and etches the oxide layer;
a processing fluid supply unit that supplies a processing fluid containing at least one of a mist of a processing liquid having affinity for the acidic polymer and a vapor of the processing liquid toward a main surface of the substrate;
a rinse liquid supply unit that supplies a rinse liquid toward the main surface of the substrate,
the processing fluid supply unit includes a processing fluid nozzle that ejects the processing fluid toward a main surface of the substrate and is movable along the main surface of the substrate;
The treatment liquid is water,
a humidification unit for adjusting the humidity of the processing fluid;
a supply path for supplying the processing fluid, the humidity of which has been adjusted by the humidification unit, to an outlet of the processing fluid nozzle;
a humidity measuring unit for measuring the humidity of the processing fluid passing through the supply path. a substrate rotation unit that rotates the substrate about a rotation axis passing through a center of a main surface of the substrate;
16. The substrate processing apparatus according to claim 13, wherein the polymer film forming unit includes a polymer-containing liquid nozzle configured to eject a polymer-containing liquid toward a main surface of the substrate, the polymer-containing liquid including at least a solvent and the acidic polymer, and forming the polymer film by evaporation of the solvent. The substrate processing apparatus of claim 16 , wherein the solvent is a liquid that is miscible with the processing liquid.

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