JP7122251B2 - Substrate processing method and substrate processing apparatus - Google Patents

Description

The present invention relates to a substrate processing method and substrate processing apparatus for processing a substrate. Substrates include, for example, semiconductor wafers, FPD (Flat Panel Display) substrates such as liquid crystal display devices and organic EL (electroluminescence) display devices, optical disk substrates, magnetic disk substrates, magneto-optical disk substrates, and photomask substrates. , ceramic substrates, solar cell substrates, and the like.

In the manufacturing process of semiconductor devices, FPDs, and the like, substrates such as semiconductor wafers and glass substrates for FPDs are processed as necessary. Such processing includes supplying a processing liquid such as a chemical liquid or a rinse liquid to the substrate. After the processing liquid is applied, the processing liquid is removed from the substrate and the substrate is dried. 2. Description of the Related Art In a single-wafer type substrate processing apparatus that processes substrates one by one, spin drying is performed in which a substrate is dried by removing liquid on the substrate by rotating the substrate at high speed.

When a pattern is formed on the surface of the substrate, the pattern may collapse when the substrate is dried due to the force caused by the surface tension of the processing liquid adhering to the substrate. As countermeasures, a method of supplying a liquid having a low surface tension such as IPA (isopropyl alcohol) to the substrate, or supplying a hydrophobizing agent to the substrate to bring the contact angle of the liquid to the pattern closer to 90 degrees is adopted. However, even if IPA or a hydrophobizing agent is used, the collapsing force for collapsing the pattern does not become zero. There is

In recent years, sublimation drying has attracted attention as a technique for preventing pattern collapse. For example, Patent Literature 1 discloses a substrate processing method and a substrate processing apparatus that perform sublimation drying. In the sublimation drying described in Patent Document 1, a sublimation substance solution is supplied to the upper surface of the substrate, and DIW (deionized water) on the substrate is replaced with the sublimation substance solution. Thereafter, the solvent for the sublimable substance is evaporated to precipitate the sublimable substance. Thereby, a film made of a solid sublimable substance is formed on the upper surface of the substrate. The substrate is then heated. Thereby, the sublimable substance on the substrate is sublimated and removed from the substrate.

JP 2012-243869 A

In general, sublimation drying has a lower pattern collapse rate than conventional drying methods such as spin drying that removes liquid by rotating the substrate at high speed and IPA drying that uses IPA. However, if the strength of the pattern is extremely low, even if sublimation drying is carried out, it may not be possible to sufficiently prevent the pattern from collapsing. According to research by the inventors of the present application, one of the causes for this is found to be the thickness of the film made of the solid sublimable substance.

The solid thickness of the sublimable substance corresponds to the thickness of the solution of the sublimable substance when the saturation concentration of the sublimable substance is reached. If the concentration of the sublimable material in the solution of the sublimable material can be known before reaching the saturation concentration of the sublimable material, the solid thickness of the sublimable material can be predicted and the solid thickness of the sublimable material with an inappropriate thickness can be estimated. formation can be avoided.
Generally, in order to measure the concentration of a substance in a liquid, it is necessary to bring the concentration measuring instrument into contact with the liquid. Since the solution of the sublimable substance formed on the substrate is relatively thin, it is difficult to bring the concentration measuring instrument into contact with the liquid film without contacting the upper surface of the substrate. Therefore, the pattern may be damaged and collapsed due to contact with a device for measuring density.

SUMMARY OF THE INVENTION Accordingly, one object of the present invention is to provide a substrate processing method and a substrate processing apparatus capable of reducing the rate of pattern collapse that occurs when a sublimable substance is removed from the upper surface of a substrate by sublimation. .

In one embodiment of the present invention, a pre-drying treatment liquid, which is a solution in which a sublimation substance is dissolved in a solvent, is supplied to the upper surface of a substrate on which a pattern is formed, and a liquid film of the pre-drying treatment liquid is formed on the substrate. a pre-drying treatment liquid supplying step formed on the upper surface of the substrate, a deposition step of depositing a solid of the sublimable substance on the upper surface of the substrate by evaporating the solvent from the liquid film, and the deposition step, The concentration of the sublimable substance in the liquid film is the reference concentration based on the film thickness reduction rate, which is the speed at which the thickness of the liquid film decreases due to the evaporation of the solvent, before the solid of the sublimable substance precipitates. a concentration determination step of determining whether or not the concentration is within the range; and when the concentration of the sublimable substance in the liquid film is determined to be within the reference concentration range in the concentration determination step, the precipitation step is terminated. and a sublimation step of sublimating the solid of the sublimable substance.

According to this method, a solution in which a sublimable substance is dissolved in a solvent is supplied to the upper surface of the substrate. As a result, a liquid film of the pre-drying treatment liquid is formed on the upper surface of the substrate. After that, the solvent is evaporated from the liquid film of the pre-drying treatment liquid. The concentration of the sublimable substance in the liquid film of the pre-drying treatment liquid increases as the solvent evaporates. When the concentration of the sublimable substance reaches the saturation concentration of the sublimable substance, the solid of the sublimable substance precipitates in the liquid film of the drying pretreatment liquid.

The inventors of the present application have found that there is a correlation between the film thickness reduction rate and the concentration of the sublimable substance in the liquid film. Therefore, if it is determined whether or not the concentration of the sublimable substance in the liquid film is within the reference concentration range based on the rate of decrease in the thickness of the liquid film of the pre-drying treatment liquid in the precipitation step, the solid state of the sublimable substance is deposited, that is, before the concentration of the sublimable substance reaches the saturated concentration of the sublimable substance, it is possible to determine whether the concentration of the sublimable substance in the liquid film is within the reference concentration range. . If the concentration of the sublimable substance in the liquid film is determined to be within the reference concentration range, a solid of the sublimable substance having an appropriate thickness is formed. Further, since the solid of the sublimable substance is sublimated after the deposition step is completed, a substrate with a reduced pattern collapse rate can be obtained.

On the other hand, when it is determined that the concentration of the sublimable substance in the liquid film is not within the standard concentration range, the substrate processing is interrupted to prevent sublimation of the solid sublimable substance having an inappropriate thickness. be able to. As a result, it is possible to suppress an increase in the pattern collapse rate.
In one embodiment of the present invention, the concentration determination step determines the sublimability in the liquid film by comparing preliminarily measured reference data with the film thickness reduction rate measured during the deposition step. It includes the step of estimating the concentration of the substance. Therefore, the concentration of the sublimable substance in the liquid film can be easily estimated during the deposition process.

In one embodiment of the present invention, in the substrate processing method, when it is determined in the concentration determination step that the concentration of the sublimable substance in the liquid film is not within the reference concentration range, the sublimation step is performed in the deposition step. The method further includes a pre-drying treatment liquid removing step of removing the pre-drying treatment liquid from the upper surface of the substrate by supplying a removal liquid to the upper surface of the substrate before the solid of the volatile substance precipitates.

According to this method, when the concentration of the sublimable substance in the liquid film is not within the reference concentration range, the sublimable substance is removed from the upper surface of the substrate with the removal liquid before the solid of the sublimable substance precipitates. can be done. As a result, it is possible to prevent a sublimable substance solid having an inappropriate thickness from being formed on the upper surface of the substrate. Therefore, it is possible to suppress an increase in the pattern collapse rate. In addition, since the pre-drying treatment liquid on the upper surface of the substrate is removed, the substrate can be reused.

In one embodiment of the present invention, in the substrate processing method, when it is determined in the concentration determination step that the concentration of the sublimable substance in the liquid film is lower than the lower limit of the reference concentration range, the precipitation Further comprising a solvent evaporation promoting step for promoting evaporation of the solvent from the liquid film during execution of the step.
According to this method, when it is determined in the concentration determining step that the concentration of the sublimable substance in the liquid film of the pre-drying treatment liquid is lower than the lower limit value of the reference concentration range, the concentration of the sublimable substance from the liquid film of the pre-drying treatment liquid Evaporation of the solvent is facilitated. When the evaporation of the solvent from the liquid film of the pre-drying treatment liquid is accelerated, the concentration of the sublimable substance in the liquid film of the pre-drying treatment liquid increases. Therefore, the concentration of the sublimable substance in the liquid film of the pre-drying treatment liquid can be adjusted within the reference concentration range. Therefore, even if it is determined in the concentration determining step that the concentration of the sublimable substance in the liquid film of the pre-drying treatment liquid is lower than the lower limit of the reference concentration range, it is possible to obtain a substrate with a reduced pattern collapse rate. can.

In one embodiment of the present invention, the solvent evaporation promoting step includes the step of removing vapor of the solvent from the atmosphere in contact with the liquid film by supplying an inert gas toward the atmosphere in contact with the liquid film.
According to this method, the vapor of the solvent is removed from the atmosphere in contact with the liquid film of the pre-drying treatment liquid on the upper surface of the substrate by supplying an inert gas. Therefore, the evaporation of the solvent from the liquid film of the pre-drying treatment liquid can be promoted.

In one embodiment of the present invention, the substrate processing method includes, in the deposition step, a substrate rotation step of rotating the upper surface of the substrate about a rotation axis along a vertical direction; When it is determined that the concentration of the sublimable substance is higher than the upper limit of the reference concentration range, the rotation speed of the substrate is increased before the solid of the sublimable substance is deposited during the deposition step. and a thinning step of thinning the liquid film by allowing the liquid film to thin.

When the concentration of the sublimable substance in the liquid film of the pre-drying treatment liquid is higher than the upper limit of the reference concentration range, the solid thickness of the sublimable substance immediately before sublimation becomes larger than the intended value. When the thickness of the liquid film of the pre-drying treatment liquid on the substrate is reduced, the amount of the sublimable substance contained in the liquid film of the pre-drying treatment liquid is reduced, so the solid thickness of the sublimable substance is also reduced.
Therefore, when the concentration of the sublimable substance in the liquid film of the pre-drying treatment liquid is higher than the upper limit of the reference concentration range, the rotation speed of the substrate is increased so that the liquid film of the pre-drying treatment liquid on the upper surface of the substrate is reduced. By applying centrifugal force, the thickness of the liquid film of the pre-drying treatment liquid can be reduced before the solid of the sublimable substance precipitates. As a result, a sublimable substance solid having an intended thickness can be deposited. Therefore, even if it is determined in the concentration determining step that the concentration of the sublimable substance in the liquid film of the pre-drying treatment liquid is higher than the upper limit value of the reference concentration range, it is possible to obtain a substrate with a reduced pattern collapse rate. can.

In one embodiment of the present invention, in the substrate processing method, when it is determined in the concentration determination step that the concentration of the sublimable substance in the liquid film is higher than the upper limit value of the reference concentration range, the precipitation It further includes a solvent evaporation suppression step of suppressing evaporation of the solvent from the liquid film during execution of the step.
According to this method, when it is determined in the concentration determination step that the concentration of the sublimable substance in the liquid film is higher than the upper limit of the reference concentration range, evaporation of the solvent from the liquid film of the pre-drying treatment liquid is suppressed. be done. When the evaporation of the solvent from the liquid film of the pre-drying treatment liquid is suppressed, the proportion of sublimable substances in the substances evaporated from the liquid film increases. This reduces the concentration of the sublimable substance in the liquid film of the pre-drying treatment liquid. Therefore, the concentration of the sublimable substance in the liquid film of the pre-drying treatment liquid can be adjusted within the reference concentration range.

Therefore, even if it is determined in the concentration determination step that the concentration of the sublimable substance in the liquid film of the pre-drying treatment liquid is higher than the upper limit of the reference concentration range, it is possible to obtain a substrate with a reduced pattern collapse rate. can.
In one embodiment of the present invention, the solvent evaporation suppression step includes a step of suppressing evaporation of the solvent from the liquid film by supplying vapor or mist of the solvent to an atmosphere in contact with the liquid film.

According to this method, by supplying vapor or mist of the solvent to the atmosphere in contact with the liquid film of the pre-drying treatment liquid on the upper surface of the substrate, the amount of the solvent present in the atmosphere in contact with the liquid film of the pre-drying treatment liquid is determined. increases. Therefore, evaporation of the solvent from the liquid film of the pre-drying treatment liquid is suppressed.
In one embodiment of the present invention, in the substrate processing method, when it is determined in the concentration determination step that the concentration of the sublimable substance in the liquid film is not within the reference concentration range, a first abnormality is notified. Further includes an anomaly notification step. Therefore, based on the notification of the abnormality, it is possible to determine at appropriate timing whether to continue the substrate processing.

In one embodiment of the present invention, the substrate processing method includes, in the deposition step, a film thickness measurement step of measuring the thickness of the liquid film immediately before the solid of the sublimable substance is deposited by evaporation of the solvent; A thickness determination step of determining whether or not the thickness of the liquid film measured in the film thickness measurement step is within a reference thickness range of the solid of the sublimable substance.
According to this method, the thickness of the liquid film immediately before the solid of the sublimable substance precipitates, that is, when the concentration of the sublimable substance reaches the saturation concentration of the sublimable substance, is within the reference thickness range of the solid of the sublimable substance. It is determined whether it is within This makes it possible to determine whether or not the solid thickness of the sublimable substance formed on the upper surface of the substrate is appropriate.

If the solid of sublimable material formed on the upper surface of the substrate has an appropriate thickness, a solid of sublimable material having an appropriate thickness is formed after the deposition step is completed. Therefore, a substrate with a reduced pattern collapse rate can be obtained.
On the other hand, when the solid thickness of the sublimation substance formed on the upper surface of the substrate is not appropriate, the substrate processing is interrupted, thereby suppressing an increase in the collapse rate of the pattern.

In one embodiment of the present invention, the substrate processing method notifies an abnormality when the thickness of the liquid film measured in the film thickness measuring step is determined not to be within the reference thickness range in the thickness determining step. It further includes a second anomaly notification step. Therefore, based on the notification of the abnormality, it is possible to determine at appropriate timing whether to continue the substrate processing.
In one embodiment of the present invention, the substrate processing method evaporates the solvent from the pre-drying treatment liquid on the upper surface of the substrate so that the solid of the sublimable substance is removed from the upper surface of the substrate. a first deposition step of precipitating in a pre-drying treatment liquid; and a first dissolving step of dissolving at least part of the solid of the sublimable substance in the pre-drying treatment liquid on the upper surface of the substrate in the first precipitation step. and a final deposition step of depositing the solid of the sublimable substance on the upper surface of the substrate by evaporating the solvent from the pre-drying treatment liquid in which the solid of the sublimable substance is dissolved in the first dissolving step. and further including Furthermore, the precipitation step is the first precipitation step, and the sublimation step is performed after the final precipitation step is completed. Further, the first dissolving step is performed when the thickness of the liquid film is determined to be within the reference thickness range in the thickness determining step.

When the solid of the sublimable substance starts to precipitate in the first precipitation step, the pre-drying treatment liquid remains on the upper surface of the substrate. In the first dissolving step, at least part of the solid of the sublimable substance is dissolved in this drying pretreatment liquid. After that, in the final precipitation step, the solvent is again evaporated from the pre-drying treatment liquid. This reduces the solvent content and deposits a solid sublimable substance on the upper surface of the substrate.

Before the solid sublimable substance is deposited for the first time, the drying pretreatment liquid is present not only between the patterns but also above the patterns. Pattern intervals are narrow on substrates such as semiconductor wafers and FPD substrates. When the space between the patterns is narrow, the pre-drying treatment liquid between the patterns is the bulk of the pre-drying treatment liquid, that is, the pre-drying treatment located in the range from the surface of the pre-drying treatment liquid on the upper surface of the substrate to the upper surface of the pattern. It has different properties from liquid. The difference between the two properties becomes more pronounced as the pattern spacing becomes narrower.

If the pattern spacing is narrow, when the solid sublimable substance is deposited first, the solid sublimable substance is deposited only in the bulk of the drying pretreatment liquid, and the solid sublimable substance does not exist between the patterns. Alternatively, almost non-existent under-deposited regions may form within the top surface of the substrate. In this case, since the surface tension of the dry pretreatment liquid between the patterns is applied to the sides of the pattern, the pattern in the incompletely precipitated region may collapse when the solid of the sublimable substance sublimes. This causes an increase (worsening) in the collapse rate of the pattern.

On the other hand, if the deposited solid of the sublimable substance is dissolved in the pre-drying treatment liquid and then deposited again, the solid of the sublimable substance can be deposited even in a narrow space such as a space between patterns. crystal nuclei are formed. Therefore, if the solid of the sublimable substance deposited in the first dissolving step is dissolved in the pre-drying treatment liquid, and then the solid of the sublimable substance is deposited again in the final deposition step, even if the pattern spacing is narrow. Also, it is possible to prevent the occurrence of the incompletely precipitated region or reduce its area.

Further, according to this method, the first dissolving step is started when the thickness of the liquid film of the pre-drying treatment liquid is determined to be within the reference thickness range in the thickness determination step. That is, the first dissolution step is triggered by the formation of a sublimable substance solid having an appropriate thickness. Therefore, the first dissolution step, the final precipitation step and the sublimation step are performed only when a solid of sublimable material of suitable thickness is formed. After the sublimation process is finished, a substrate with a reduced pattern collapse rate can be obtained.

If a sublimable substance solid having an appropriate thickness is not formed, the substrate is processed without executing the steps after the first deposition step (the first dissolution step, the final deposition step, and the sublimation step). Can be interrupted early.
In one embodiment of the present invention, the substrate processing method evaporates the solvent from the pre-drying treatment liquid on the upper surface of the substrate so that the solid of the sublimable substance is removed from the upper surface of the substrate. a first deposition step of precipitating in a pre-drying treatment liquid; a first dissolving step of dissolving at least part of a solid of the sublimable substance in the pre-drying treatment liquid on the upper surface of the substrate; and a final deposition step of depositing the solid of the sublimable substance on the upper surface of the substrate by evaporating the solvent from the pre-drying treatment liquid in which the solid of the sublimation is dissolved. Further, the precipitation step includes at least one of the first precipitation step and the final precipitation step, and the sublimation step is performed after the final precipitation step.

According to this method, after the precipitated solid of the sublimable substance is dissolved in the drying pretreatment liquid, the solid of the sublimable substance precipitates again. Therefore, even if the pattern spacing is narrow, it is possible to prevent the occurrence of an incomplete precipitation region or reduce its area. As a result, pattern collapse can be reduced, and the pattern collapse rate can be lowered.
Further, according to this method, in at least one of the first precipitation step and the final precipitation step, before the solid of the sublimable substance precipitates, that is, before the concentration of the sublimable substance reaches the saturation concentration of the sublimable substance. First, it is determined whether or not the concentration of the sublimable substance in the liquid film is within the reference concentration range. If the concentration of the sublimable substance in the liquid film is determined to be within the reference concentration range, a solid of the sublimable substance having an appropriate thickness is formed. Further, since the solid of the sublimable substance is sublimated after the final deposition step is completed, it is possible to obtain a substrate with a reduced pattern collapse rate.

On the other hand, when it is determined that the concentration of the sublimable substance in the liquid film is not within the standard concentration range, the substrate processing is interrupted to prevent sublimation of the solid sublimable substance having an inappropriate thickness. be able to. As a result, it is possible to suppress an increase in the pattern collapse rate.
Since the collapse rate of the pattern depends on the thickness of the sublimable substance solid finally formed on the upper surface of the substrate, the concentration determination step is preferably performed in the final deposition step. However, the amount of solvent evaporated in the first dissolution step and the final precipitation step is predictable. Therefore, even if the concentration determination step is executed in the first deposition step, the solid state of the sublimable substance formed on the upper surface of the substrate is determined based on the concentration of the sublimable substance in the liquid film during the first deposition step. It is possible to determine whether the thickness of is appropriate.

According to another embodiment of the present invention, a pre-drying treatment liquid, which is a solution in which a sublimation substance is dissolved in a solvent, is supplied to the upper surface of a substrate on which a pattern is formed, and the liquid film of the pre-drying treatment liquid is formed as described above. a step of supplying a pre-drying treatment liquid formed on the upper surface of a substrate; a deposition step of depositing a solid of the sublimable substance on the upper surface of the substrate by evaporating the solvent from the liquid film; After the solid of the sublimation substance is deposited by evaporation of the solvent, the surface of the solid of the sublimation substance is measured by measuring the height positions of the solid of the sublimation substance at a plurality of locations on the upper surface of the substrate. a flatness measuring step of measuring the flatness of the flatness of the flatness measuring step; a flatness determining step of determining whether the flatness measured in the flatness measuring step is within a reference flatness range; and a sublimation step of sublimating the solid of the sublimable substance when determined to be within the reference flat range.

According to this method, a solution in which a sublimable substance is dissolved in a solvent is supplied to the upper surface of the substrate. As a result, a liquid film of the pre-drying treatment liquid is formed on the upper surface of the substrate. After that, the solvent is evaporated from the liquid film of the pre-drying treatment liquid. The concentration of the sublimable substance in the liquid film of the pre-drying treatment liquid increases as the solvent evaporates. When the concentration of the sublimable substance reaches the saturation concentration of the sublimable substance, the solid of the sublimable substance precipitates in the liquid film of the drying pretreatment liquid.

If the solid of the sublimable substance has a portion that is too thin or a portion that is too thick, the collapse rate of the pattern in that portion may increase. Therefore, the degree of flatness of the solid surface of the sublimation substance deposited on the upper surface of the substrate is measured, and it is determined whether or not the measured degree of flatness is within the reference flatness range. As a result, it is possible to check whether or not a sublimable solid having a uniform thickness is formed over the entire upper surface of the substrate.

When the degree of flatness of the solid of the sublimable substance is determined to be within the reference flatness range, the solid of the sublimable substance is sublimated, so that a substrate with a reduced pattern collapse rate can be obtained. On the other hand, when it is determined that the flatness of the sublimable substance solid is not within the reference flatness range, the substrate processing is interrupted, thereby suppressing the generation of the substrate with an increased pattern collapse rate.
In another embodiment of the present invention, the substrate processing method comprises supplying a removing liquid to the upper surface of the substrate when the flatness is determined not to be within the reference flatness range in the flatness measuring step. and removing solids of the sublimable material from the upper surface of the substrate.

According to this method, when the degree of flatness of the solid of the sublimable substance is not within the reference flatness range, the solid of the sublimable substance is removed from the upper surface of the substrate by the removal liquid. Therefore, it is possible to suppress the pattern from collapsing even when the solid of the sublimation substance has a portion that is too thin or a portion that is too thick. In addition, since the sublimable substance solid on the upper surface of the substrate is removed, the substrate can be reused.

In still another embodiment of the present invention, a pre-drying treatment liquid, which is a solution in which a sublimable substance is dissolved in a solvent, is applied to the upper surface of the patterned substrate so that a liquid film is formed on the upper surface of the substrate. a solvent evaporation unit for evaporating the solvent from the liquid film so that the solid of the sublimable substance precipitates; and a film thickness measurement unit for measuring the thickness of the liquid film. , a sublimation unit for sublimating the solid of the sublimable substance formed on the substrate, and a controller for determining whether the concentration of the sublimable substance in the liquid film is within a reference concentration range, A substrate processing apparatus is provided. According to this configuration, the same effects as those of the substrate processing method described above can be obtained.

FIG. 1A is a schematic top view of a substrate processing apparatus according to an embodiment of the present invention. FIG. 1B is a schematic side view of the substrate processing apparatus. FIG. 2 is a schematic horizontal view of the inside of a processing unit provided in the substrate processing apparatus. FIG. 3 is a schematic horizontal view of a film thickness measuring unit, a spin chuck, and a blocking member provided in the processing unit. FIG. 4 is a schematic top view of the film thickness measurement unit and the spin chuck. FIG. 5 is a cross-sectional view showing the inside of a housing containing a light-emitting element provided in the film thickness measurement unit. FIG. 6 is a cross-sectional view along line VI-VI shown in FIG. FIG. 7 is a schematic diagram showing a pre-drying treatment liquid supply device provided in the substrate processing apparatus. FIG. 8 is a block diagram showing hardware of a controller provided in the substrate processing apparatus. FIG. 9 is a flowchart for explaining an example of substrate processing by the substrate processing apparatus. FIG. 10A is a schematic diagram showing the state of the substrate when a solution of camphor and IPA is used. FIG. 10B is a schematic diagram showing the state of the substrate when a solution of camphor and IPA is used. FIG. 10C is a schematic diagram showing the state of the substrate when a solution of camphor and IPA is used. FIG. 10D is a schematic diagram showing the state of the substrate when a solution of camphor and IPA is used. FIG. 10E is a schematic diagram showing the state of the substrate when a solution of camphor and IPA is used. FIG. 10F is a schematic diagram showing the state of the substrate when a solution of camphor and IPA is used. FIG. 11 is an equilibrium diagram of camphor and IPA. FIG. 12A is a schematic diagram showing the state of the substrate when a solution of camphor and methanol is used. FIG. 12B is a schematic diagram showing the state of the substrate when a solution of camphor and methanol is used. FIG. 12C is a schematic diagram showing the state of the substrate when a solution of camphor and methanol is used. FIG. 12D is a schematic diagram showing the state of the substrate when a solution of camphor and methanol is used. FIG. 13 is a graph showing the pattern collapse rate. FIG. 14 is a graph showing temporal changes in the thickness of the liquid film of the pre-drying treatment liquid on the upper surface of the substrate until the solid of the sublimable substance precipitates from the pre-drying treatment liquid. FIG. 15 is a flow chart showing the flow of the first example of the film thickness monitoring process. FIG. 16 is a schematic diagram for explaining the abnormality handling process in the first example of the film thickness monitoring process. FIG. 17 is a flow chart showing the flow of the second example of the film thickness monitoring process. FIG. 18 is a schematic diagram for explaining the solvent evaporation suppression step in the second example of the film thickness monitoring step. FIG. 19 is a schematic diagram for explaining the solvent evaporation acceleration step in the second example of the film thickness monitoring step. FIG. 20 is a flow chart showing the flow of the third example of the film thickness monitoring process. FIG. 21A is a schematic diagram for explaining the thinning process in the third example of the film thickness monitoring process. FIG. 21B is a schematic diagram for explaining the thinning process in the third example of the film thickness monitoring process. FIG. 22 is a flow chart showing the flow of the fourth example of the film thickness monitoring process. FIG. 23 is a flowchart for explaining another example of substrate processing by the substrate processing apparatus. FIG. 24 is a flow chart showing the flow of the fifth example of the film thickness monitoring process. FIG. 25A is a schematic diagram for explaining a flatness degree measuring step in the substrate processing. FIG. 25B is a schematic diagram for explaining a solid removal step in the substrate processing. FIG. 25C is a schematic diagram for explaining a solid removal step in the substrate processing.

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings.
In the following description, unless otherwise specified, the atmospheric pressure in the substrate processing apparatus 1 is maintained at the atmospheric pressure in the clean room in which the substrate processing apparatus 1 is installed (for example, 1 atmospheric pressure or a value in the vicinity thereof). .
FIG. 1A is a schematic top view of a substrate processing apparatus 1 according to an embodiment of the present invention. FIG. 1B is a schematic diagram of the substrate processing apparatus 1 viewed from the side.

As shown in FIG. 1A, the substrate processing apparatus 1 is a single-wafer type apparatus that processes disk-shaped substrates W such as semiconductor wafers one by one. The substrate processing apparatus 1 includes a load port LP that holds a carrier CA that accommodates substrates W, and a plurality of processes that process the substrates W transported from the carrier CA on the load port LP with a processing fluid such as a processing liquid or a processing gas. It includes a unit 2 , a transport robot that transports substrates W between the carrier CA on the load port LP and the processing unit 2 , and a controller 3 that controls the substrate processing apparatus 1 .

The transport robots include an indexer robot IR that loads and unloads substrates W into and out of carriers CA on load port LP, and a center robot CR that loads and unloads substrates W into and out of a plurality of processing units 2 . The indexer robot IR transports substrates W between the load port LP and the center robot CR, and the center robot CR transports the substrates W between the indexer robot IR and the processing units 2 . The center robot CR includes a hand H1 that supports the substrate W, and the indexer robot IR includes a hand H2 that supports the substrate W. As shown in FIG.

The plurality of processing units 2 form a plurality of towers TW arranged around the center robot CR in plan view. FIG. 1A shows an example in which four towers TW are formed. The center robot CR can access any tower TW. As shown in FIG. 1B, each tower TW includes a plurality (for example, three) of processing units 2 stacked one above the other.

FIG. 2 is a schematic horizontal view of the inside of the processing unit 2 provided in the substrate processing apparatus 1. As shown in FIG.
The processing unit 2 is a wet processing unit 2w that supplies the substrate W with processing liquid. The processing unit 2 includes a box-shaped chamber 4 having an internal space, and a spin device that horizontally holds one substrate W in the chamber 4 and rotates it around a vertical rotation axis A1 that passes through the center of the upper surface of the substrate W. It includes a chuck 10 and a cylindrical processing cup 21 surrounding the spin chuck 10 about the axis of rotation A1.

The chamber 4 includes a box-shaped partition wall 5 provided with a loading/unloading port 5b through which the substrate W passes, and a shutter 7 for opening and closing the loading/unloading port 5b. The FFU 6 (fan filter unit) is arranged above the blower port 5 a provided on the upper part of the partition wall 5 . The FFU 6 constantly supplies clean air (filtered air) into the chamber 4 from the blower port 5a. Gas in the chamber 4 is exhausted from the chamber 4 through an exhaust duct 8 connected to the bottom of the processing cup 21 . Thereby, a clean air downflow is always formed in the chamber 4 . The flow rate of the exhaust discharged to the exhaust duct 8 is changed according to the opening of the exhaust valve 9 arranged inside the exhaust duct 8 .

The spin chuck 10 includes a disc-shaped spin base 12 held in a horizontal posture, a plurality of chuck pins 11 holding the substrate W in a horizontal posture above the spin base 12 , and It includes a spin shaft 13 extending downward, and a spin motor 14 that rotates the spin base 12 and the plurality of chuck pins 11 by rotating the spin shaft 13 . The spin chuck 10 is not limited to a clamping type chuck in which a plurality of chuck pins 11 are brought into contact with the outer peripheral surface of the substrate W, and the back surface (lower surface) of the substrate W, which is a non-device forming surface, is attracted to the upper surface 12u of the spin base 12. Therefore, it may be a vacuum type chuck that holds the substrate W horizontally.

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

The guard 24 includes a cylindrical portion 25 surrounding the spin chuck 10 and an annular ceiling portion 26 extending obliquely upward from the upper end of the cylindrical portion 25 toward the rotation axis A1. The plurality of ceiling portions 26 overlap vertically, and the plurality of cylindrical portions 25 are arranged concentrically. The annular upper end of the ceiling portion 26 corresponds to the upper end 24u of the guard 24 surrounding the substrate W and the spin base 12 in plan view. The plurality of cups 23 are arranged below the plurality of cylindrical portions 25, respectively. The cup 23 forms an annular liquid receiving groove that receives the processing liquid guided downward by the guard 24 .

The processing unit 2 includes a guard lifting unit 27 that lifts and lowers the plurality of guards 24 individually. The guard lifting unit 27 positions the guard 24 at any position from the upper position to the lower position. The guard lifting unit 27 is also called a guard lifter. FIG. 2 shows two guards 24 in the upper position and the remaining two guards 24 in the lower position. The upper position is a position where the upper end 24u of the guard 24 is arranged above the holding position where the substrate W held by the spin chuck 10 is arranged. The lower position is a position where the upper end 24u of the guard 24 is arranged below the holding position.

At least one guard 24 is placed in the upper position when supplying the processing liquid to the rotating substrate W. As shown in FIG. When the processing liquid is supplied to the substrate W in this state, the processing liquid supplied to the substrate W is shaken off around the substrate W. As shown in FIG. The shaken-off processing liquid collides with the inner surface of the guard 24 horizontally facing the substrate W and is guided to the cup 23 corresponding to the guard 24 . Thereby, the processing liquid discharged from the substrate W is collected in the processing cup 21 .

The processing unit 2 includes a plurality of nozzles that eject processing liquid toward the substrate W held by the spin chuck 10 . The plurality of nozzles includes a chemical liquid nozzle 31 that discharges a chemical liquid toward the upper surface of the substrate W, a rinse liquid nozzle 35 that discharges a rinse liquid toward the upper surface of the substrate W, and a pre-drying treatment liquid toward the upper surface of the substrate W. and a replacement liquid nozzle 43 for ejecting a replacement liquid toward the upper surface of the substrate W. As shown in FIG.

The chemical liquid nozzle 31 may be a scan nozzle horizontally movable within the chamber 4 or a fixed nozzle fixed to the partition wall 5 of the chamber 4 . The same applies to the rinse liquid nozzle 35 , the pre-drying treatment liquid nozzle 39 , and the replacement liquid nozzle 43 . In FIG. 2, the chemical liquid nozzle 31, the rinse liquid nozzle 35, the pre-drying treatment liquid nozzle 39, and the replacement liquid nozzle 43 are scan nozzles, and four nozzle moving units corresponding to these four nozzles are provided. shows an example.

The chemical nozzle 31 is connected to a chemical pipe 32 that guides the chemical to the chemical nozzle 31 . When the chemical liquid valve 33 interposed in the chemical liquid pipe 32 is opened, the chemical liquid is continuously discharged downward from the discharge port of the chemical liquid nozzle 31 . The chemical liquid discharged from the chemical liquid nozzle 31 includes sulfuric acid, nitric acid, hydrochloric acid, hydrofluoric acid, phosphoric acid, acetic acid, ammonia water, hydrogen peroxide water, organic acids (eg, citric acid, oxalic acid, etc.), organic alkalis (eg, TMAH: tetramethylammonium hydroxide, etc.), a surfactant, and a corrosion inhibitor, or other liquids.

Although not shown, the chemical valve 33 includes a valve body provided with an annular valve seat through which the chemical passes, a valve body movable with respect to the valve seat, a closed position where the valve body contacts the valve seat, and a valve body. an actuator for moving the valve body between an open position in which the body is away from the valve seat. The same applies to other valves. The actuator may be a pneumatic actuator, an electric actuator, or an actuator other than these. The controller 3 opens and closes the chemical valve 33 by controlling the actuator.

The chemical liquid nozzle 31 is connected to a nozzle moving unit 34 that moves the chemical liquid nozzle 31 in at least one of the vertical direction and the horizontal direction. The nozzle moving unit 34 moves the chemical liquid nozzle between a processing position where the chemical liquid discharged from the chemical liquid nozzle 31 is supplied to the upper surface of the substrate W and a standby position where the chemical liquid nozzle 31 is positioned around the processing cup 21 in plan view. Move 31 horizontally.

The rinse liquid nozzle 35 is connected to a rinse liquid pipe 36 that guides the rinse liquid to the rinse liquid nozzle 35 . When the rinse liquid valve 37 interposed in the rinse liquid pipe 36 is opened, the rinse liquid is continuously discharged downward from the discharge port of the rinse liquid nozzle 35 . The rinse liquid discharged from the rinse liquid nozzle 35 is, for example, pure water (deionized water: DIW). The rinse liquid may be any one of carbonated water, electrolytic ion water, hydrogen water, ozone water, and diluted hydrochloric acid water (for example, about 10 ppm to 100 ppm).

The rinse liquid nozzle 35 is connected to a nozzle moving unit 38 that moves the rinse liquid nozzle 35 in at least one of the vertical direction and the horizontal direction. The nozzle moving unit 38 is located between a processing position where the rinse liquid discharged from the rinse liquid nozzle 35 is supplied to the upper surface of the substrate W and a standby position where the rinse liquid nozzle 35 is positioned around the processing cup 21 in plan view. to move the rinse liquid nozzle 35 horizontally.

The pre-drying treatment liquid nozzle 39 is connected to a pre-drying treatment liquid pipe 40 that guides the treatment liquid to the pre-drying treatment liquid nozzle 39 . When the pre-drying treatment liquid valve 41 interposed in the pre-drying treatment liquid pipe 40 is opened, the pre-drying treatment liquid is continuously discharged downward from the outlet of the pre-drying treatment liquid nozzle 39 . Similarly, the substituting liquid nozzle 43 is connected to a substituting liquid pipe 44 that guides the substituting liquid to the substituting liquid nozzle 43 . When the substitution liquid valve 45 interposed in the substitution liquid pipe 44 is opened, the substitution liquid is continuously discharged downward from the discharge port of the substitution liquid nozzle 43 .

The drying pretreatment liquid is a solution containing a sublimable substance as a solute and a solvent that dissolves the sublimable substance. The sublimable substance may be a substance that changes from a solid to a gas at normal temperature (synonymous with room temperature) or normal pressure (the pressure in the substrate processing apparatus 1, for example, 1 atmosphere or a value in the vicinity thereof) without going through a liquid state. good.
The freezing point of the pre-drying treatment liquid (the freezing point at 1 atm; the same shall apply hereinafter) is lower than room temperature (for example, 23° C. or a value in the vicinity thereof). The substrate processing apparatus 1 is arranged in a clean room maintained at room temperature. Therefore, the pre-drying treatment liquid can be kept liquid without heating the pre-drying treatment liquid. The freezing point of the sublimable substance is higher than that of the drying pretreatment liquid. The freezing point of sublimable substances is above room temperature. At room temperature, sublimable substances are solid. The freezing point of the sublimable substance may be higher than the boiling point of the solvent. The vapor pressure of the solvent is higher than the vapor pressure of the sublimable substance.

Examples of sublimable substances include alcohols such as 2-methyl-2-propanol (alias: tert-butyl alcohol, t-butyl alcohol) and cyclohexanol, fluorocarbon compounds, 1,3,5-trioxane (alias : metaformaldehyde), camphor (a.k.a. camphor, camphor), naphthalene, and iodine, or other substances.

Solvents include, for example, pure water, IPA, methanol, HFE (hydrofluoroether), acetone, PGMEA (propylene glycol monomethyl ether acetate), PGEE (propylene glycol monoethyl ether, 1-ethoxy-2-propanol), and ethylene glycol. At least one selected from the group consisting of may be used.
An example in which the sublimable substance is camphor and the solvent is IPA or methanol will be described below.

The freezing point of camphor is between 175°C and 177°C. The freezing point of camphor is higher than the boiling point of the solvent, whether the solvent is IPA or methanol. The vapor pressure of IPA is higher than that of camphor. Similarly, the vapor pressure of methanol is higher than that of camphor. Therefore, IPA and methanol are easier to evaporate than camphor. IPA has a higher vapor pressure than water and a lower surface tension than water. Similarly, methanol has a higher vapor pressure than water and a lower surface tension than water. Both IPA and methanol have higher molecular weights than water. Methanol has a lower molecular weight than IPA.

As will be described later, the replacement liquid is supplied to the upper surface of the substrate W covered with the liquid film of the rinse liquid, and the pre-drying treatment liquid is supplied to the upper surface of the substrate W covered with the liquid film of the replacement liquid. The replacement liquid may be any liquid as long as it dissolves with both the rinse liquid and the pre-drying liquid. The replacement liquid is, for example, IPA (liquid). The replacement liquid may be a mixed liquid of IPA and HFE, or may be other than these. The replacement liquid may be a liquid with the same name as a component of the pre-drying treatment liquid such as a solvent, or may be a liquid with a different name from any component of the pre-drying treatment liquid.

When the replacement liquid is supplied to the upper surface of the substrate W covered with the liquid film of the rinse liquid, most of the rinse liquid on the substrate W is washed away by the replacement liquid and discharged from the substrate W. FIG. A small amount of the remaining rinsing liquid dissolves in the replacement liquid and diffuses into the replacement liquid. The diffused rinse liquid is discharged from the substrate W together with the replacement liquid. Therefore, the rinse liquid on the substrate W can be efficiently replaced with the replacement liquid. For the same reason, the replacement liquid on the substrate W can be efficiently replaced with the pre-drying treatment liquid. Thereby, the rinse liquid contained in the pre-drying treatment liquid on the substrate W can be reduced.

The pre-drying treatment liquid nozzle 39 is connected to a nozzle moving unit 42 that moves the pre-drying treatment liquid nozzle 39 in at least one of the vertical direction and the horizontal direction. The nozzle moving unit 42 has a processing position where the pre-drying treatment liquid discharged from the pre-drying treatment liquid nozzle 39 is supplied to the upper surface of the substrate W, and a position where the pre-drying treatment liquid nozzle 39 is positioned around the processing cup 21 in plan view. The pre-drying treatment liquid nozzle 39 is moved horizontally between the standby position where the drying is performed.

Similarly, the replacement liquid nozzle 43 is connected to a nozzle moving unit 46 that moves the replacement liquid nozzle 43 in at least one of vertical and horizontal directions. The nozzle moving unit 46 is located between a processing position where the replacement liquid discharged from the replacement liquid nozzle 43 is supplied to the upper surface of the substrate W and a standby position where the replacement liquid nozzle 43 is positioned around the processing cup 21 in plan view. to move the substituting liquid nozzle 43 horizontally.

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

The blocking member 51 is connected to a blocking member elevating unit 54 that vertically moves the blocking member 51 up and down. The blocking member elevating unit 54 is also called a blocking member lifter. The blocking member elevating unit 54 positions the blocking member 51 at any position from the upper position (the position shown in FIG. 2) to the lower position. The lower position is a close position where the lower surface 51L of the shielding member 51 approaches the upper surface of the substrate W to a height at which the scan nozzle such as the chemical nozzle 31 cannot enter between the substrate W and the shielding member 51 . The upper position is a separated position where the blocking member 51 is retracted to a height at which the scan nozzle can enter between the blocking member 51 and the substrate W. FIG.

The plurality of nozzles includes a central nozzle 55 that downwardly discharges a processing fluid such as a processing liquid or processing gas through an upper central opening 61 that opens at the center of the lower surface 51L of the blocking member 51 . The central nozzle 55 extends vertically along the rotation axis A1. The central nozzle 55 is arranged in a through-hole vertically penetrating the central portion of the blocking member 51 . The inner peripheral surface of the blocking member 51 surrounds the outer peripheral surface of the center nozzle 55 with a gap in the radial direction (direction orthogonal to the rotation axis A1). The center nozzle 55 moves up and down together with the blocking member 51 . A discharge port of the central nozzle 55 for discharging the processing fluid is arranged above the upper central opening 61 of the blocking member 51 .

The center nozzle 55 is connected to an upper gas pipe 56 that guides inert gas to the center nozzle 55 . The substrate processing apparatus 1 may include an upper temperature controller 59 that heats or cools the inert gas discharged from the center nozzle 55 . When the upper gas valve 57 interposed in the upper gas pipe 56 is opened, the inert gas flows through the outlet of the central nozzle 55 at a flow rate corresponding to the degree of opening of the flow control valve 58 that changes the flow rate of the inert gas. is discharged continuously downward from the The inert gas discharged from the central nozzle 55 is nitrogen gas. The inert gas discharged from the center nozzle 55 may be gas other than nitrogen gas, such as helium gas or argon gas.

The inner peripheral surface of the blocking member 51 and the outer peripheral surface of the center nozzle 55 form a cylindrical upper gas flow path 62 extending vertically. The upper gas flow path 62 is connected to an upper gas pipe 63 that guides the inert gas to the upper central opening 61 of the blocking member 51 . The substrate processing apparatus 1 may include an upper temperature controller 66 that heats or cools the inert gas discharged from the upper central opening 61 of the blocking member 51 . When the upper gas valve 64 interposed in the upper gas pipe 63 is opened, the inert gas flows at the upper center of the blocking member 51 at a flow rate corresponding to the opening degree of the flow control valve 65 that changes the flow rate of the inert gas. It is continuously discharged downward from the opening 61 . The inert gas discharged from the upper central opening 61 of the blocking member 51 is nitrogen gas. The inert gas discharged from the upper central opening 61 of the blocking member 51 may be gas other than nitrogen gas, such as helium gas or argon gas.

The plurality of nozzles includes a lower surface nozzle 71 that discharges the processing liquid toward the central portion of the lower surface of the substrate W. As shown in FIG. The lower surface nozzle 71 includes a nozzle disk portion arranged between the upper surface 12u of the spin base 12 and the lower surface of the substrate W, and a nozzle cylindrical portion extending downward from the nozzle disk portion. The discharge port of the lower surface nozzle 71 is open at the center of the upper surface of the nozzle disk portion. When the substrate W is held by the spin chuck 10, the ejection port of the lower surface nozzle 71 faces the central portion of the lower surface of the substrate W vertically.

The bottom nozzle 71 is connected to a heating fluid pipe 72 that guides hot water (pure water having a temperature higher than room temperature), which is an example of a heating fluid, to the bottom nozzle 71 . Pure water supplied to the lower surface nozzle 71 is heated by a heater 75 interposed in the heating fluid pipe 72 . When the heating fluid valve 73 interposed in the heating fluid pipe 72 is opened, the hot water flows continuously upward from the discharge port of the lower surface nozzle 71 at a flow rate corresponding to the degree of opening of the flow control valve 74 that changes the flow rate of the hot water. is ejected. As a result, hot water is supplied to the lower surface of the substrate W. As shown in FIG.

The lower surface nozzle 71 is further connected to a cooling fluid pipe 76 that guides cold water (pure water having a temperature lower than room temperature), which is an example of a cooling fluid, to the lower surface nozzle 71 . Pure water supplied to the lower surface nozzle 71 is cooled by a cooler 79 interposed in the cooling fluid pipe 76 . When the cooling fluid valve 77 interposed in the cooling fluid pipe 76 is opened, the cold water flows continuously upward from the discharge port of the lower surface nozzle 71 at a flow rate corresponding to the opening degree of the flow control valve 78 that changes the flow rate of the cold water. is ejected. Cold water is thereby supplied to the lower surface of the substrate W. As shown in FIG.

The outer peripheral surface of the lower surface nozzle 71 and the inner peripheral surface of the spin base 12 form a tubular lower gas flow path 82 extending vertically. The lower gas channel 82 includes a lower central opening 81 that opens at the central portion of the upper surface 12 u of the spin base 12 . The lower gas flow path 82 is connected to a lower gas pipe 83 that guides the inert gas to the lower central opening 81 of the spin base 12 . The substrate processing apparatus 1 may include a lower temperature controller 86 that heats or cools the inert gas discharged from the lower central opening 81 of the spin base 12 . When the lower gas valve 84 interposed in the lower gas pipe 83 is opened, the inert gas flows at the lower center of the spin base 12 at a flow rate corresponding to the opening of the flow control valve 85 that changes the flow rate of the inert gas. It is continuously discharged upward from the opening 81 .

The inert gas discharged from the lower central opening 81 of the spin base 12 is nitrogen gas. The inert gas discharged from the lower central opening 81 of the spin base 12 may be gas other than nitrogen gas, such as helium gas or argon gas. When the lower central opening 81 of the spin base 12 discharges nitrogen gas while the substrate W is held on the spin chuck 10, the nitrogen gas flows between the lower surface of the substrate W and the upper surface 12u of the spin base 12 in all directions. flow radially into Thereby, the space between the substrate W and the spin base 12 is filled with nitrogen gas.

Next, the film thickness measurement unit 91 will be described.
FIG. 3 is a schematic diagram of the film thickness measuring unit 91, the spin chuck 10 and the blocking member 51 viewed horizontally. FIG. 4 is a schematic diagram of the film thickness measurement unit 91 and the spin chuck 10 viewed from above. FIG. 5 is a cross-sectional view showing the inside of a housing 93 that accommodates the light emitting element 92. As shown in FIG. FIG. 6 is a cross-sectional view showing a cross section taken along line VI-VI shown in FIG.

As shown in FIGS. 3 and 4, the substrate processing apparatus 1 includes a film thickness measurement unit 91 for measuring the thickness (film thickness) of the liquid film on the upper surface of the substrate W. As shown in FIGS. The film thickness measurement unit 91 measures the film thickness by spectral interferometry, for example. The film thickness measurement unit 91 includes a light emitting element 92 that emits light toward the upper surface of the substrate W held by the spin chuck 10, and a light receiving element 97 that receives the light from the light emitting element 92 reflected by the upper surface of the substrate W. . The light-emitting element 92 and the light-receiving element 97 are arranged at positions that do not overlap the spin chuck 10 and the blocking member 51 in plan view.

The light emitting element 92 is arranged inside the housing 93 . The light receiving element 97 is arranged inside the housing 98 . Light from the light emitting element 92 is emitted outside the housing 93 through an opening of the housing 93 closed with a transparent plate 94 . The light from the light emitting element 92 reflected by the upper surface of the substrate W passes through the opening of the housing 98 closed with the transparent plate 99 and enters the light receiving element 97 inside the housing 98 . A black point Pi in FIGS. 3 and 4 indicates an incident position where the light from the light emitting element 92 is incident on the upper surface of the substrate W. As shown in FIG. The thickness of the liquid film on the substrate W is calculated based on the light incident on the light receiving element 97 .

As shown in FIGS. 5 and 6 , the film thickness measurement unit 91 includes a holder 95 that holds the light emitting element 92 within the housing 93 and an electric motor 96 that moves the holder 95 with respect to the housing 93 . The holder 95 and electric motor 96 are accommodated within the housing 93 . A rotor and a stator of the electric motor 96 are housed in a motor housing 96a, and a rotating shaft 96b of the electric motor 96 protrudes in the axial direction of the electric motor 96 from an end surface of the motor housing 96a. The rotating shaft 96 b is connected to the holder 95 and the motor housing 96 a is connected to the housing 93 .

A rotation angle of the electric motor 96 is controlled by the controller 3 . When the electric motor 96 rotates the rotating shaft 96 b , the holder 95 rotates together with the light emitting element 92 around the horizontal rotation axis A 2 with respect to the housing 93 . A white arrow in FIG. 5 indicates that the light emitting element 92 rotates around the rotation axis A2. As a result, the incident position where the light from the light emitting element 92 is incident on the upper surface of the substrate W moves within the upper surface of the substrate W, and the incident angle of the light from the light emitting element 92 with respect to the upper surface of the substrate W changes. Therefore, by rotating the electric motor 96, the light from the light emitting element 92 can be incident on a plurality of positions within the upper surface of the substrate W, and the film thickness can be measured at a plurality of positions within the upper surface of the substrate W. can.

When the incident position and incident angle change, the path along which the reflected light representing the light from the light emitting element 92 reflected on the upper surface of the substrate W also changes. The light receiving element 97 may be movable so as to receive the reflected light even if the path of the reflected light changes. For example, an electric motor may be provided to move the light receiving element 97 with respect to the housing 98 as well as the light emitting element 92 . Alternatively, a plurality of light receiving elements 97 corresponding to one light emitting element 92 may be provided. In these cases, the reflected light is received by the light receiving element 97 and the thickness of the liquid film on the substrate W is measured even if the incident position and incident angle are changed.

When measuring the thickness of the liquid film on the substrate W, the controller 3 may position the incident position at a constant horizontal distance from the rotation axis A1 while rotating the substrate W on the spin chuck 10. Alternatively, the incident position may be moved in the radial direction of the substrate W (horizontal direction orthogonal to the rotation axis A1). In the latter case, the average of multiple measured values may be treated as the film thickness.
Next, the pre-drying treatment liquid supply device 101 will be described. FIG. 7 is a schematic diagram showing a pre-drying treatment liquid supply device 101 provided in the substrate processing apparatus 1. As shown in FIG.

The substrate processing apparatus 1 includes a pre-drying treatment liquid supply device 101 that supplies the pre-drying treatment liquid to the pre-drying treatment liquid nozzles 39 through a pre-drying treatment liquid pipe 40 . The pre-drying treatment liquid supply device 101 includes a first tank 102A corresponding to a stock solution tank storing the undiluted solution of the pre-drying treatment liquid, and a second tank 102B corresponding to a solvent tank storing the solvent of the pre-drying treatment liquid. .
The undiluted solution of the pre-drying treatment liquid contains a sublimable substance and a solvent. The undiluted solution of the pre-drying treatment liquid has a higher concentration of the sublimable substance than the pre-drying treatment liquid supplied to the substrate W. The undiluted solution of the pre-drying treatment liquid is supplied to the substrate W after being diluted with the solvent supplied from the second tank 102B. When the sublimable substance is liquid at room temperature, the stock solution of the pre-drying treatment liquid may not contain a solvent.

The pre-drying treatment liquid supply device 101 includes a first circulation pipe 103A for circulating the stock solution in the first tank 102A, a first pump 104A for sending the stock solution in the first tank 102A to the first circulation pipe 103A, a first circulation and a first individual pipe 105A that guides the undiluted solution in the pipe 103A to the drying pretreatment liquid pipe 40. The pre-drying treatment liquid supply device 101 changes the flow rate of the pre-drying treatment liquid supplied from the first individual piping 105A to the pre-drying treatment liquid piping 40, and the first on-off valve 106A that opens and closes the inside of the first individual piping 105A. It further includes a first flow control valve 107A.

Similarly, the pre-drying treatment liquid supply device 101 includes a second circulation pipe 103B that circulates the solvent in the second tank 102B, a second pump 104B that sends the solvent in the second tank 102B to the second circulation pipe 103B, and a second individual pipe 105B that guides the solvent in the second circulation pipe 103B to the drying pretreatment liquid pipe 40 . The pre-drying treatment liquid supply device 101 changes the flow rate of the pre-drying treatment liquid supplied from the second individual piping 105B to the pre-drying treatment liquid piping 40, and the second on-off valve 106B that opens and closes the inside of the second individual piping 105B. and a second flow control valve 107B.

The first individual pipe 105A and the second individual pipe 105B are connected to the pre-drying treatment liquid pipe 40 via a mixing valve 108 that generates the pre-drying treatment liquid by mixing the undiluted solution of the pre-drying treatment liquid and the solvent. there is The pre-drying treatment liquid pipe 40 is provided not only with the pre-drying treatment liquid valve 41 but also with an in-line mixer 109 . In-line mixer 109 further mixes the dry pretreatment liquid produced by mixing valve 108 . As a result, the pre-drying treatment liquid in which the sublimable substance and the solvent are uniformly mixed is supplied to the pre-drying treatment liquid nozzle 39 .

The undiluted solution of the pre-drying treatment liquid supplied from the first tank 102A is supplied to the mixing valve 108 at a flow rate corresponding to the opening degree of the first flow rate control valve 107A. The solvent supplied from the second tank 102B is supplied to the mixing valve 108 at a flow rate corresponding to the degree of opening of the second flow control valve 107B. Therefore, by changing the opening degrees of the first flow rate control valve 107A and the second flow rate control valve 107B, the concentration of the sublimable substance in the pre-drying treatment liquid supplied to the pre-drying treatment liquid nozzle 39 can be changed.

The pre-drying treatment liquid supply device 101 includes a densitometer 110 for measuring the concentration of the pre-drying treatment liquid supplied to the pre-drying treatment liquid nozzle 39 . The pre-drying treatment liquid supply device 101 includes a measurement pipe 111 branched from the pre-drying treatment liquid pipe 40 . A densitometer 110 is interposed in a measurement pipe 111 . FIG. 7 shows an example in which the measurement pipe 111 is connected to the drying pretreatment liquid pipe 40 at a position downstream of the in-line mixer 109 . Therefore, in this example, the concentration of the dry pretreatment liquid that has passed through both the mixing valve 108 and the in-line mixer 109 is measured by the densitometer 110 . The concentration meter 110 may be interposed in the pre-drying treatment liquid pipe 40 between the pre-drying treatment liquid valve 41 and the in-line mixer 109 instead of the measurement pipe 111 .

FIG. 8 is a block diagram showing the hardware of the controller 3. As shown in FIG.
The controller 3 is a computer including a computer main body 3a and peripheral devices 3d connected to the computer main body 3a. The computer body 3a includes a CPU 3b (central processing unit) that executes various commands, and a main storage device 3c that stores information. The peripheral device 3d includes an auxiliary storage device 3e that stores information such as the program P, a reading device 3f that reads information from the removable medium RM, and a communication device 3g that communicates with other devices such as a host computer.

The controller 3 is connected to the input device 100A, display device 100B, and alarm device 100C. The input device 100</b>A is operated when an operator such as a user or a person in charge of maintenance inputs information to the substrate processing apparatus 1 . Information is displayed on the screen of the display device 100B. The input device 100A may be one of a keyboard, pointing device, and touch panel, or may be a device other than these. The substrate processing apparatus 1 may be provided with a touch panel display that serves as both the input device 100A and the display device 100B. The alarm device 100C issues an alarm using one or more of light, sound, characters, and graphics. When the input device 100A is a touch panel display, the input device 100A may also serve as the alarm device 100C.

The CPU 3b executes the program P stored in the auxiliary storage device 3e. The program P in the auxiliary storage device 3e may be pre-installed in the controller 3, may be sent from the removable medium RM to the auxiliary storage device 3e through the reading device 3f, or may be stored in the host computer. It may be sent from an external device such as a computer to the auxiliary storage device 3e through the communication device 3g.

The auxiliary storage device 3e and removable media RM are non-volatile memories that retain data even when power is not supplied. The auxiliary storage device 3e is, for example, a magnetic storage device such as a hard disk drive. The removable medium RM is, for example, an optical disk such as a compact disk or a semiconductor memory such as a memory card. The removable medium RM is an example of a computer-readable recording medium on which the program P is recorded. The removable medium RM is a tangible recording medium that is not temporary.

The auxiliary storage device 3e stores a plurality of recipes. The recipe is information that defines the processing content, processing conditions, and processing procedure of the substrate W. FIG. The plurality of recipes differ from each other in at least one of the processing content of the substrate W, the processing conditions, and the processing procedure. The controller 3 controls the substrate processing apparatus 1 so that the substrate W is processed according to the recipe specified by the host computer. Each of the following steps is executed by the controller 3 controlling the substrate processing apparatus 1 . In other words, controller 3 is programmed to perform the following steps.

Next, an example of substrate processing will be described.
The substrate W to be processed is, for example, a semiconductor wafer such as a silicon wafer. The surface of the substrate W corresponds to a device forming surface on which devices such as transistors and capacitors are formed. The substrate W may be the substrate W having the pattern PA (see FIG. 10A) formed on the surface of the substrate W, which is the device formation surface, or the substrate W having no pattern PA formed on the surface of the substrate W. may In the latter case, the pattern PA may be formed in the chemical solution supply step, which will be described later.

First, an example of substrate treatment (first substrate treatment example) in which the pre-drying treatment liquid is a solution of camphor and IPA will be described.
FIG. 9 is a process chart for explaining substrate processing performed by the substrate processing apparatus 1. FIG. 10A to 10F are schematic diagrams showing the state of the substrate W when a solution of camphor and IPA is used. FIG. 11 is an equilibrium diagram of camphor and IPA. RT in FIG. 11 means room temperature. In the following, reference is made to FIGS. 2 and 9. FIG. 10A-10F and FIG. 11 will be referred to accordingly.

When the substrate processing apparatus 1 processes the substrate W, a loading step (step S1 in FIG. 9) of loading the substrate W into the chamber 4 is performed.
Specifically, the center robot CR (Fig. 1) moves the hand H1 into the chamber 4 while supporting the substrate W with the hand H1. Then, the center robot CR places the substrate W on the hand H1 on the plurality of chuck pins 11 with the surface of the substrate W facing upward. After that, a plurality of chuck pins 11 are pressed against the outer peripheral surface of the substrate W, and the substrate W is gripped. Thereby, the substrate W is held by the spin chuck 10 (substrate holding step). The substrate holding process is continued until the sublimation process (step S10 in FIG. 9), which will be described later, ends. After placing the substrate W on the spin chuck 10 , the center robot CR withdraws the hand H<b>1 from the interior of the chamber 4 .

Next, the upper gas valve 64 and the lower gas valve 84 are opened, and the upper central opening 61 of the blocking member 51 and the lower central opening 81 of the spin base 12 start discharging nitrogen gas. Thereby, the space between the substrate W and the blocking member 51 is filled with nitrogen gas. Similarly, the space between the substrate W and the spin base 12 is filled with nitrogen gas. Meanwhile, the guard lifting unit 27 lifts at least one guard 24 from the lower position to the upper position. Thereafter, the spin motor 14 is driven to start rotating the substrate W at a predetermined liquid supply speed (substrate rotating step). The substrate rotation process is continued until the sublimation process (step S10 in FIG. 9), which will be described later, ends.

Next, a chemical liquid supply step (step S2 in FIG. 9) is performed for supplying the chemical liquid to the upper surface of the substrate W to form a liquid film of the chemical liquid covering the entire upper surface of the substrate W. FIG.
Specifically, the nozzle moving unit 34 moves the chemical liquid nozzle 31 from the standby position to the processing position in a state where the blocking member 51 is positioned at the upper position and at least one guard 24 is positioned at the upper position. . After that, the chemical liquid valve 33 is opened, and the chemical liquid nozzle 31 starts discharging the chemical liquid (chemical liquid supply process, chemical liquid discharging process). After a predetermined period of time has passed since the chemical valve 33 was opened, the chemical valve 33 is closed and the discharge of the chemical is stopped. After that, the nozzle moving unit 34 moves the liquid medicine nozzle 31 to the standby position.

The chemical liquid discharged from the chemical liquid nozzle 31 collides with the upper surface of the substrate W rotating at a predetermined chemical liquid supply speed, and then flows outward along the upper surface of the substrate W due to centrifugal force. Therefore, the chemical solution is supplied to the entire upper surface of the substrate W, and a liquid film of the chemical solution covering the entire upper surface of the substrate W is formed. When the chemical liquid nozzle 31 is discharging the chemical liquid, the nozzle moving unit 34 may move the liquid landing position of the chemical liquid on the upper surface of the substrate W so that the liquid landing position passes through the central portion and the outer peripheral portion, The liquid landing position may be stationary at the central portion.

Next, a rinse step (step S3 in FIG. 9) is performed in which pure water, which is an example of a rinse liquid, is supplied to the upper surface of the substrate W to wash away the chemical liquid on the substrate W. FIG.
Specifically, the nozzle moving unit 38 moves the rinse liquid nozzle 35 from the standby position to the processing position in a state where the blocking member 51 is positioned at the upper position and at least one guard 24 is positioned at the upper position. Let After that, the rinse liquid valve 37 is opened, and the rinse liquid nozzle 35 starts discharging the rinse liquid (rinse liquid supply process, rinse liquid discharge process). The guard elevating unit 27 may vertically move at least one guard 24 to switch the guard 24 that receives the liquid discharged from the substrate W before the pure water discharge is started. After a predetermined period of time has passed since the rinse liquid valve 37 was opened, the rinse liquid valve 37 is closed and the discharge of the rinse liquid is stopped. After that, the nozzle moving unit 38 moves the rinse liquid nozzle 35 to the standby position.

The pure water discharged from the rinse liquid nozzle 35 collides with the upper surface of the substrate W rotating at a predetermined rinse liquid supply speed, and then flows outward along the upper surface of the substrate W due to centrifugal force. The chemical liquid on the substrate W is replaced with pure water discharged from the rinse liquid nozzle 35 . As a result, a pure water liquid film covering the entire upper surface of the substrate W is formed. While the rinse liquid nozzle 35 is discharging pure water, the nozzle moving unit 38 moves the pure water landing position on the upper surface of the substrate W so that the pure water landing position passes through the central portion and the outer peripheral portion. Alternatively, the liquid landing position may be stationary at the central portion.

Next, a replacement treatment step (step S4 in FIG. 9) is performed in which a replacement liquid that dissolves with both the rinsing liquid and the pre-drying treatment liquid is supplied to the upper surface of the substrate W to replace the pure water on the substrate W with the replacement liquid. .
Specifically, the nozzle moving unit 46 moves the replacement liquid nozzle 43 from the waiting position to the processing position while the blocking member 51 is positioned at the upper position and at least one guard 24 is positioned at the upper position. Let After that, the substitution liquid valve 45 is opened, and the substitution liquid nozzle 43 starts discharging the substitution liquid (substitution liquid supply process, substitution liquid discharge process). The guard elevating unit 27 may vertically move at least one guard 24 in order to switch the guard 24 that receives the liquid discharged from the substrate W before the discharge of the replacement liquid is started. After a predetermined period of time has passed since the substitution liquid valve 45 was opened, the substitution liquid valve 45 is closed and the discharge of the substitution liquid is stopped. After that, the nozzle moving unit 46 moves the replacement liquid nozzle 43 to the standby position.

The replacement liquid discharged from the replacement liquid nozzle 43 collides with the upper surface of the substrate W rotating at a predetermined replacement liquid supply speed, and then flows outward along the upper surface of the substrate W due to centrifugal force. The pure water on the substrate W is replaced with the replacement liquid discharged from the replacement liquid nozzle 43 . As a result, a liquid film of the replacement liquid covering the entire upper surface of the substrate W is formed. When the substituting liquid nozzle 43 is discharging the substituting liquid, the nozzle moving unit 46 moves the substituting liquid landing position on the upper surface of the substrate W so that the substituting liquid landing position passes through the central portion and the outer peripheral portion. Alternatively, the liquid landing position may be stationary at the central portion. Further, after the liquid film of the replacement liquid covering the entire upper surface of the substrate W is formed, the substrate W is moved at a paddle speed (for example, a speed exceeding 0 and 20 rpm or less) while stopping the ejection of the replacement liquid from the replacement liquid nozzle 43 . You can also rotate with .

Next, a pre-drying treatment liquid supply step (step S5 in FIG. 9) is performed to supply the pre-drying treatment liquid to the upper surface of the substrate W to form a liquid film of the pre-drying treatment liquid on the substrate W. FIG.
Specifically, the blocking member 51 is positioned at the upper position and at least one guard 24 is positioned at the upper position, and the nozzle moving unit 42 moves the pre-drying treatment liquid nozzle 39 from the waiting position to the processing position. move to After that, the pre-drying treatment liquid valve 41 is opened, and the pre-drying treatment liquid nozzle 39 starts discharging the pre-drying treatment liquid (pre-drying treatment liquid supplying step, pre-drying treatment liquid discharging step). The guard elevating unit 27 may vertically move at least one guard 24 in order to switch the guard 24 that receives the liquid discharged from the substrate W before the discharge of the pre-drying treatment liquid is started. When a predetermined time has passed since the pre-drying treatment liquid valve 41 was opened, the pre-drying treatment liquid valve 41 is closed, and the discharge of the pre-drying treatment liquid is stopped. After that, the nozzle moving unit 42 moves the pre-drying treatment liquid nozzle 39 to the standby position.

After the pre-drying treatment liquid discharged from the pre-drying treatment liquid nozzle 39 collides with the upper surface of the substrate W rotating at a predetermined pre-drying treatment liquid supply speed, it is pushed outward along the upper surface of the substrate W by centrifugal force. flow to The drying pretreatment liquid supply speed is, for example, 500 rpm. The replacement liquid on the substrate W is replaced with the pre-drying treatment liquid discharged from the pre-drying treatment liquid nozzle 39 . As a result, a liquid film of the pre-drying treatment liquid (pre-drying treatment liquid film 120) covering the entire upper surface of the substrate W is formed (pre-drying treatment liquid film forming step). Thus, the pre-drying treatment liquid nozzle 39 is an example of a pre-drying treatment liquid supply unit that supplies the pre-drying treatment liquid onto the upper surface of the substrate W so that the pre-drying treatment liquid film 120 is formed on the upper surface of the substrate W. be.

When the pre-drying treatment liquid nozzle 39 is discharging the pre-drying treatment liquid, the nozzle moving unit 42 lands the pre-drying treatment liquid on the upper surface of the substrate W so that the position where the pre-drying treatment liquid lands passes through the central portion and the outer peripheral portion. The position may be moved, or the liquid landing position may be stationary at the central portion.
Next, a film thickness reduction step of reducing the thickness (film thickness) of the pre-drying treatment liquid film 120 on the substrate W while maintaining the state where the entire upper surface of the substrate W is covered with the liquid film of the pre-drying treatment liquid ( Step S6) in FIG. 9 is performed.

Specifically, the blocking member elevating unit 54 moves the blocking member 51 from the upper position to the lower position. The spin motor 14 maintains the rotation speed of the substrate W at the film thickness reduction rotation speed in a state where the blocking member 51 is positioned at the lower position and at least one guard 24 is positioned at the upper position. The film thickness reduction rotation speed may be equal to or different from the pre-drying treatment liquid supply speed. The pre-drying treatment liquid on the substrate W is discharged outward from the substrate W by centrifugal force even after the ejection of the pre-drying treatment liquid is stopped. Therefore, the thickness of the pre-drying treatment liquid film 120 on the substrate W is reduced. When the pre-drying treatment liquid on the substrate W is discharged to some extent, the amount of the pre-drying treatment liquid discharged from the substrate W per unit time is reduced to zero or substantially zero. As a result, the thickness of the pre-drying treatment liquid film 120 on the substrate W is stabilized at a value corresponding to the substrate W rotation speed.

After the thickness of the pre-drying treatment liquid film 120 is reduced in the film thickness reduction step (step S6 in FIG. 9), a sublimable solid 121 (see FIG. 10B) is precipitated in the pre-drying treatment liquid on the substrate W. A first deposition step (precipitation step) (step S7 in FIG. 9) is performed.
Specifically, in a state in which the blocking member 51 is positioned at the lower position and at least one guard 24 is positioned at the upper position, the spin motor 14 rotates the substrate W to a predetermined first deposition speed. maintain. The first deposition rate may be equal to or different from the drying pretreatment liquid supply rate. The first deposition speed is, for example, 500 rpm. Since the vapor pressure of the solvent is higher than the vapor pressure of the sublimation substance, while the substrate W is rotating at the first deposition speed, the solvent evaporates from the pre-drying treatment liquid at an evaporation speed higher than that of the sublimation substance. Evaporate from the surface. FIG. 10A shows a state in which the solvent evaporates from the surface of the pre-drying treatment liquid.

As the solvent continues to evaporate, the thickness of the pre-drying treatment liquid film 120 gradually decreases, and the concentration of the sublimable substance on the surface of the pre-drying treatment liquid film 120 and its vicinity gradually increases. Evaporation of the solvent from the pre-drying treatment liquid film 120 is performed without forcibly heating the pre-drying treatment liquid film 120 on the substrate W, for example. Therefore, the solvent evaporates from the pre-drying treatment liquid while the pre-drying treatment liquid film 120 on the substrate W is maintained at room temperature or slightly lower than room temperature. When the concentration of the sublimable substance on and near the surface of the pre-drying treatment liquid film 120 reaches the saturation concentration of the sublimable substance in the pre-drying treatment liquid, as shown in FIG. Deposits on the surface of the treatment liquid film 120 (room temperature deposition process, liquid surface deposition process). In the first deposition step, the spin motor 14 functions as a solvent evaporation unit that evaporates the solvent from the dry pretreatment liquid film 120 so that the sublimable substance solid 121 is deposited.

As shown in FIG. 10B, when the solid 121 of the sublimable substance is deposited, the bulk of the pre-drying treatment liquid, that is, the dry pre-treatment liquid located in the range from the surface (liquid surface) of the pre-drying treatment liquid film 120 to the upper surface of the pattern PA. All or part of the pretreatment liquid changes into a sublimable solid 121 . In FIG. 10B, only the pre-drying treatment liquid on the surface side of the pre-drying treatment liquid film 120 in the pre-drying treatment liquid film 120 has changed into a sublimable solid 121, and the rest of the pre-drying treatment liquid film 120 is It shows an example maintained in a liquid. In this example, the sublimable substance solid 121 does not reach the upper surface of the pattern PA, and the drying pretreatment liquid is not only between the patterns PA but also between the sublimable substance solid 121 and the upper surface of the pattern PA. is also left. All or part of the surface of the pre-drying treatment liquid film 120 is covered with a film-like sublimable substance solid 121 extending horizontally, that is, a solidified film (solid film).

Next, a first dissolving step (step S8 in FIG. 9) of dissolving the sublimable solid 121 in the pre-drying treatment liquid on the substrate W is performed.
Specifically, with the blocking member 51 positioned at the lower position and at least one guard 24 positioned at the upper position, the spin motor 14 sets the rotational speed of the substrate W to the predetermined first melting speed. maintain. The first dissolution rate may be equal to or different from the drying pretreatment liquid supply rate. The first dissolution rate is, for example, 500 rpm. Furthermore, the heating fluid valve 73 is opened, and the lower surface nozzle 71 starts discharging hot water (pure water having a temperature higher than room temperature). The guard elevating unit 27 may vertically move at least one guard 24 to switch the guard 24 that receives the liquid discharged from the substrate W before hot water discharge is started.

The hot water discharged from the lower surface nozzle 71 flows outward along the lower surface of the substrate W after colliding with the central portion of the lower surface of the substrate W rotating at the first melting speed. Thereby, the entire area of the substrate W is heated at a heating temperature higher than the room temperature. The heat of the hot water is transferred to the pre-drying treatment liquid on the substrate W through the substrate W. FIG. The pre-drying treatment liquid film 120 on the substrate W is indirectly heated via the substrate W (indirect heating step). Thereby, the temperature of the sublimable substance solid 121 on the substrate W and the temperature of the pre-drying treatment liquid film 120 are maintained at a temperature higher than room temperature.

As shown in FIG. 10C, when the temperature of the pre-drying treatment liquid film 120 on the substrate W is increased, the saturated concentration of the sublimation substance in the pre-drying treatment liquid rises, and the sublimation substance solid 121 on the substrate W increases. dissolved in the drying pretreatment liquid. The dissolution of the sublimable substance solid 121 in the pre-drying treatment liquid is promoted by the temperature rise of the pre-drying treatment liquid. As a result, all or most of the sublimable substance solid 121 dissolves in the drying pretreatment liquid on the substrate W. As shown in FIG. FIG. 10D shows an example in which all the sublimable substance solids 121 are dissolved in the drying pretreatment liquid.

After dissolving the sublimable substance solid 121 in the pre-drying treatment liquid, the sublimable solid 121 may be precipitated again, and the precipitated sublimable substance solid 121 may be dissolved again in the pre-drying treatment liquid. That is, one repeating cycle from the first precipitation step (step S7 in FIG. 9) to the first dissolution step (step S8 in FIG. 9) may be performed twice or more.
"N" in FIG. 9 means an integer of 0 or more. When N is 1 or more, the repeating cycle is performed two or more times, and then the final deposition step (step S9 in FIG. 9) is performed. When N is 0, the first precipitation step (step S7 in FIG. 9) and the first dissolution step (step S8 in FIG. 9) are performed once each, and after that, the sublimation substance solid 121 is precipitated again. A deposition step (step S9 in FIG. 9) is performed.

Specifically, the spin motor 14 maintains the rotation speed of the substrate W at a predetermined final deposition speed while the blocking member 51 is positioned at the lower position and at least one guard 24 is positioned at the upper position. do. The final deposition rate may be equal to or different from the dry pretreatment liquid feed rate. The final deposition speed is, for example, 500 rpm. The discharge of hot water from the lower surface nozzle 71 continues from the first dissolving step (step S8 in FIG. 9). Therefore, the dried pretreatment liquid on the substrate W is maintained at a temperature higher than room temperature while the substrate W is rotating at the final deposition speed.

As shown in FIG. 10D, solvent evaporates from the surface of the dry pretreatment liquid film 120 while the substrate W is rotating at the final deposition speed. Therefore, as the surface of the pre-drying treatment liquid gradually approaches the base of the pattern PA, the concentration of the sublimable substance in the pre-drying treatment liquid film 120 gradually increases. When the concentration of the sublimable substance in the pre-drying treatment liquid film 120 reaches the saturation concentration of the sublimable substance in the pre-drying treatment liquid, the solid 121 of the sublimable substance precipitates on the upper surface of the substrate W, and all or almost all of the drying is completed. The pretreatment liquid disappears from the substrate W. In the final deposition step, the spin motor 14 and the bottom nozzle 71 function as a solvent evaporation unit that evaporates the solvent from the dry pretreatment liquid film 120 so that the sublimable substance solid 121 is deposited.

FIG. 10E shows an example in which all the drying pretreatment liquid is gone and a sublimable solid 121 is deposited between the patterns PA. FIG. 10E shows an example in which the thickness of the sublimable substance solid 121 is greater than the height of the pattern PA.
FIG. 11 is an equilibrium diagram of camphor and IPA. A solution of camphor and IPA corresponds to the dry pretreatment liquid. The curve (clotting curve) in FIG. 11 indicates the freezing points of solutions of camphor and IPA. The thick polygonal line in FIG. 11 indicates that the first precipitation step (step S7 in FIG. 9), the first dissolution step (step S8 in FIG. 9), and the final precipitation step (step S9 in FIG. 9) were performed once each. 9 shows the transition of the concentration of camphor and the temperature of the solution when N=0 in FIG.

In FIG. 11, a thick straight line from point P1 to point P2 indicates that the first precipitation step (step S8 in FIG. 9) is being performed. When the first precipitation step (step S8 in FIG. 9) is performed, IPA evaporates from the solution of camphor and IPA corresponding to the dry pretreatment liquid, and the concentration of camphor gradually increases. At this time, the temperature of the pre-drying treatment liquid is maintained at or near room temperature. When the concentration of camphor increases to the concentration at point P2 in FIG. 11, a solid 121 of sublimable material containing camphor and IPA is formed by precipitation or solidification.

In FIG. 11, a thick straight line from point P2 to point P3 indicates that the first melting step (step S8 in FIG. 9) is being performed. When the first dissolving step (step S8 in FIG. 9) is being performed, the temperature of the solution of camphor and IPA rises, and the temperature of the sublimable substance solid 121 is higher than the freezing point of the solution of camphor and IPA. rise to temperature. This melts or dissolves at least a portion of the sublimable substance solid 121 back into the solution of camphor and IPA.

In FIG. 11, the thick straight line from point P3 to point P4 indicates that the final precipitation step (step S9 in FIG. 9) is being performed. As previously mentioned, when the final precipitation step (step S9 in FIG. 9) is being performed, rather than lowering the temperature of the solution of camphor and IPA to re-precipitate the sublimable solids 121, camphor and IPA is further evaporated while maintaining the solution above room temperature. Therefore, the sublimable substance solid 121 having a lower IPA content than the sublimable substance solid 121 deposited in the first deposition step (step S7 in FIG. 9) is deposited.

After the solid 121 of the sublimable substance is deposited between the patterns PA, the sublimation step (step S10 in FIG. 9) of sublimating the solid 121 of the sublimable substance and removing it from the upper surface of the substrate W is performed.
Specifically, the spin motor 14 maintains the rotation speed of the substrate W at a predetermined sublimation speed while the blocking member 51 is positioned at the lower position. The sublimation rate may be equal to or different from the pre-drying treatment liquid supply rate. The sublimation speed is, for example, 1500 rpm. Further, the upper gas valve 57 is opened and the center nozzle 55 starts discharging nitrogen gas. In addition to or instead of opening the upper gas valve 57 , the degree of opening of the flow control valve 65 may be changed to increase the flow rate of nitrogen gas discharged from the upper central opening 61 of the blocking member 51 .

When the rotation of the substrate W at the sublimation speed or the like is started, sublimation of the sublimation substance solid 121 on the substrate W starts, and gas containing the sublimation substance is generated from the sublimation substance solid 121 on the substrate W. do. The gas (gas containing the sublimable substance) generated from the sublimable substance solid 121 radially flows through the space between the substrate W and the blocking member 51 and is discharged from above the substrate W. FIG. Then, after a certain amount of time has passed since the sublimation started, all the sublimable substance solids 121 are removed from the substrate W, as shown in FIG. 10F. After that, the spin motor 14 is stopped and the rotation of the substrate W is stopped. Furthermore, the upper gas valve 57 is closed and the central nozzle 55 stops discharging nitrogen gas.

In this manner, the central nozzle 55, the upper central opening 61 of the blocking member 51, and the spin motor 14 function as a sublimation unit for sublimating the sublimable substance solid 121 on the upper surface of the substrate W. FIG.
Instead of discharging the nitrogen gas described above, a heat source such as a heating element or a lamp may be arranged above or below the substrate W, and the sublimation substance may be sublimated by heating with these heat sources.
Further, as will be described later, when the sublimation substance solid 121 precipitates on the substrate W, the detection value of the film thickness measurement unit 91 changes significantly, so the controller 3 monitors the detection value of the film thickness measurement unit 91. Thus, it can be determined whether or not the solid 121 of the sublimable substance has precipitated. Therefore, the controller 3 preliminarily sets a threshold for the film thickness at an arbitrary position within the upper surface of the substrate W to be measured by the film thickness measurement unit 91. You may control so that it may shift to a process.

Next, the unloading step (step S11 in FIG. 9) of unloading the substrate W from the chamber 4 is performed.
Specifically, the blocking member lifting unit 54 lifts the blocking member 51 to the upper position, and the guard lifting unit 27 lowers all the guards 24 to the lower position. Furthermore, the upper gas valve 64 and the lower gas valve 84 are closed, and the upper central opening 61 of the blocking member 51 and the lower central opening 81 of the spin base 12 stop discharging nitrogen gas. After that, the center robot CR makes the hand H1 enter the chamber 4 . After the plurality of chuck pins 11 release the grip of the substrate W, the center robot CR supports the substrate W on the spin chuck 10 with the hand H1. After that, the center robot CR withdraws the hand H1 from the inside of the chamber 4 while supporting the substrate W with the hand H1. Thereby, the processed substrate W is unloaded from the chamber 4 .

Next, an example of substrate treatment (second substrate treatment example) in which the pre-drying treatment liquid is a solution of camphor and methanol will be described.
The general flow of the second substrate processing example is similar to that of the first substrate processing example, and is shown in FIG. The second substrate processing example differs from the first substrate processing example in the steps from the first dissolving step (step S8 in FIG. 9) to the final deposition step (step S9 in FIG. 9), and the other steps are different. is the same as the first substrate processing example. Therefore, the steps from the first dissolution step to the final deposition step in the second substrate processing example will be described below.

12A to 12D are schematic diagrams showing the state of the substrate W when a solution of camphor and methanol is used. In the following, reference is made to FIGS. 2 and 9. FIG. Reference will be made to FIGS. 12A to 12D as appropriate.
After the sublimation substance solid 121 is deposited in the initial first deposition step (step S7 in FIG. 9), the sublimation substance solid 121 is dissolved in the pre-drying treatment liquid on the substrate W in the first dissolution step (FIG. 9). 9 step S8) is performed.

Specifically, with the blocking member 51 positioned at the lower position and at least one guard 24 positioned at the upper position, the spin motor 14 sets the rotational speed of the substrate W to the predetermined first melting speed. maintain. The first dissolution rate may be equal to or different from the drying pretreatment liquid supply rate. The first dissolution rate is, for example, 1500 rpm. When the substrate W is rotating at the first dissolution speed, the controller 3 may close the upper gas valve 64 to stop the discharge of nitrogen gas from the upper central opening 61 of the blocking member 51 . Alternatively, the controller 3 may reduce the flow rate of the nitrogen gas discharged from the upper central opening 61 of the blocking member 51 by changing the degree of opening of the flow control valve 65 .

When the solvent evaporates from the pre-drying treatment liquid in the first deposition step (step S7 in FIG. 9), the heat of the pre-drying treatment liquid corresponding to the heat of vaporization is released into the atmosphere in the chamber 4 together with the solvent, and the pre-drying treatment The surface temperature of the liquid drops. When the sublimable solid 121 is formed, less solvent evaporates from the pre-drying liquid, and thus less heat is released from the pre-drying liquid into the atmosphere. At the same time, as shown in FIG. 12A, heat in the atmosphere is transferred to the pre-drying liquid through the sublimable substance solid 121 . As a result, the temperatures of the sublimable substance solid 121 and the pre-drying treatment liquid film 120 on the substrate W rise.

When the temperatures of the sublimable substance solid 121 on the substrate W and the drying pretreatment liquid film 120 rise, part of the sublimable substance solid 121 dissolves in the drying pretreatment liquid, as shown in FIG. 12B. The dry pretreatment liquid is a solution of camphor and methanol. Sublimable substance solid 121 includes camphor. The solubility of camphor in methanol is greater than the solubility of camphor in IPA, and camphor is easily soluble in methanol. As soon as a portion of the camphor solids dissolves in the methanol liquid, the rest of the camphor solids also dissolves in the methanol liquid. As a result, all or most of the sublimable substance solid 121 dissolves in the drying pretreatment liquid on the substrate W. As shown in FIG. FIG. 12C shows an example in which all of the sublimable substance solid 121 is dissolved in the drying pretreatment liquid.

When the sublimable substance solid 121 dissolves in the pre-drying treatment liquid on the substrate W, the amount of solvent evaporated from the pre-drying treatment liquid increases, and the temperature of the surface of the pre-drying treatment liquid decreases. As a result, as shown in FIG. 12D, the concentration of the sublimable substance on the surface of the pre-drying treatment liquid increases, and the sublimable substance solid 121 precipitates again on the surface of the pre-drying treatment liquid (step S7 in FIG. 9). . When the sublimable substance solid 121 precipitates again, the temperatures of the sublimable substance solid 121 and the drying pretreatment liquid rise as described above, and the sublimable substance solid 121 dissolves in the drying pretreatment liquid again (FIG. 9). step S8).

In this way, when the pre-drying treatment liquid is a solution of camphor and methanol, the pre-drying treatment liquid can be sublimated simply by leaving the pre-drying treatment liquid on the upper surface of the substrate W without forcibly changing the temperature of the pre-drying treatment liquid. Precipitation and dissolution of the solid substance 121 are repeated (natural precipitation process, natural dissolution process). The number of repetitions of one repetition cycle from the first precipitation step (step S7 in FIG. 9) to the first dissolution step (step S8 in FIG. 9) increases with an increase in the time for which the pre-drying treatment liquid is left. Therefore, the number of repetitions of precipitation and dissolution of the sublimable solid 121 may be set according to the allowable time.

When depositing the sublimable substance solid 121, the vapor pressure of the solvent in the atmosphere in contact with the drying pretreatment liquid on the substrate W is maintained below the saturated vapor pressure of the solvent at the temperature of the atmosphere. When the sublimable solid 121 is dissolved, the temperature of the interface between the sublimable solid 121 and the drying pretreatment liquid film 120 is adjusted to the concentration of the sublimable substance when the sublimable solid 121 is dissolved. Maintain a value above the freezing point of the pretreatment liquid. In this way, deposition and dissolution of the sublimable solid 121 are naturally repeated.

When the sublimable solid 121 is deposited and dissolved, the controller 3 may discharge a gas such as nitrogen gas at a low flow rate to at least one of the central nozzle 55 and the upper central opening 61 of the blocking member 51 . In this case, the vapor of the solvent can be quickly removed from above the substrate W, and the evaporation of the solvent can be accelerated. Furthermore, if the gas is discharged toward the upper surface of the substrate W at a low flow rate, the temperature change at the interface between the sublimable solid 121 and the pre-drying treatment liquid film 120 can be minimized. Therefore, the evaporation of the solvent can be accelerated without hindering the dissolution of the sublimable solid 121 .

The FFU 6 constantly supplies clean air into the chamber 4 . The downflow of clean air flowing toward the upper surface of the substrate W is blocked by the blocking member 51 . Thereby, disturbance of the atmosphere on the substrate W can be suppressed. The controller 3 may temporarily stop the supply of clean air to the FFU 6 when depositing and dissolving the sublimable solid 121 . In order to suppress the disturbance of the atmosphere on the substrate W, the controller 3 may cause the spin motor 14 to temporarily stop the rotation of the substrate W when the sublimable solid 121 is deposited and dissolved.

After the solid 121 of the sublimable substance is dissolved in the pre-drying treatment liquid, the final precipitation step (step S9 in FIG. 9) is performed to precipitate the solid 121 of the sublimable substance again.
Specifically, the spin motor 14 maintains the rotation speed of the substrate W at a predetermined final deposition speed while the blocking member 51 is positioned at the lower position and at least one guard 24 is positioned at the upper position. do. The final deposition rate may be equal to or different from the dry pretreatment liquid feed rate. The final deposition speed is, for example, 1500 rpm. While the substrate W is rotating at the final deposition speed, the solvent evaporates from the surface of the drying pretreatment liquid. When the concentration of the sublimable substance in the pre-drying treatment liquid reaches the saturation concentration of the sublimable substance in the pre-drying treatment liquid, the solid 121 of the sublimable substance precipitates on the upper surface of the substrate W, and all or almost all of the pre-drying treatment is carried out. The liquid is removed from the substrate W (see FIG. 10E). After that, a sublimation step (step S10 in FIG. 9) of sublimating the sublimable substance solid 121 on the substrate W is performed.

As described above, when the pre-drying treatment liquid is a solution of camphor and methanol, the pre-drying treatment liquid is simply left on the upper surface of the substrate W to repeat precipitation and dissolution of the sublimable solid 121 . If a small amount of the pre-drying liquid remains on the substrate W, the sublimable solids 121 may dissolve in the pre-drying liquid before sublimating the sublimable solids 121 . In order to prevent this, the sublimable solid 121 on the substrate W may be cooled. For example, the rotation speed of the substrate W may be increased, or the flow rate of the gas discharged toward the upper surface of the substrate W may be increased.

FIG. 13 is a graph showing the collapse rate of pattern PA. Collapse rate A and collapse rate B are values when the dry pretreatment liquid is a solution of camphor and IPA, and collapse rate C is a value when the dry pretreatment liquid is a solution of camphor and methanol.
Unlike the substrate treatment shown in FIG. 9, the "collapse rate A" is a value when the sublimable solid 121 is precipitated once and then sublimated. The “collapse rate B” is a value when the sublimable solid 121 is precipitated twice and then sublimated. That is, the "collapse rate B" is the collapse rate when N=0 in FIG. The “collapse ratio C” is a value obtained when the sublimable solid 121 is precipitated two or more times and then the sublimable solid 121 is sublimated. Except for the composition of the pre-drying treatment liquid and the number of times the sublimable solid 121 is precipitated, the treatment conditions for the substrate W are the same for the collapse rates A to C. FIG.

The collapse rate A is lower than the value when IPA drying is performed to dry the substrate W by removing the IPA on the substrate W by rotating the substrate W at high speed. Collapse rate B is lower than collapse rate A. Similarly, collapse rate C is lower than collapse rate A. Collapse rate C is lower than collapse rate B. Collapse rate B is less than half of collapse rate A. Collapse rate C is less than half of collapse rate B. The collapse rate C is less than 1%, which is extremely low.

Since the collapse rate B is lower than the collapse rate A, the collapse rate of the pattern PA can be reduced by dissolving the precipitated sublimation solid 121 in the pre-drying treatment liquid and then precipitating the sublimation solid 121 again. can be lowered. Since the collapse rate C is lower than the collapse rate B, when the sublimable substance is camphor, the collapse rate of the pattern PA can be further reduced by using methanol instead of IPA as the solvent. Therefore, even if the strength of the pattern PA is extremely low, the repetition cycle of the first precipitation step (step S7 in FIG. 9) and the first dissolution step (step S8 in FIG. 9) is repeated by 1 as in the present embodiment. If it is performed more than once, the collapse rate of the pattern PA can be reduced. That is, even if N=0 in FIG. 9, the collapse rate of the pattern PA can be reduced.

According to the studies of the present inventors, when the interval G1 (see FIG. 10A) between the patterns PA is 30 nm or less, even if sublimation drying is performed, a good collapse rate of the patterns PA may not be obtained. It is considered that this is because an incomplete deposition region in which the sublimable substance solid 121 does not exist or hardly exists between the patterns PA is formed in the upper surface of the substrate W. FIG. Therefore, by dissolving the precipitated sublimable substance solid 121 in the pre-drying treatment liquid and then depositing the sublimable substance solid 121 again, even if the substrate W has the pattern PA with the interval G1 of 30 nm or less, It is possible to reduce the collapse rate of the pattern PA.

Next, changes in the thickness of the pre-drying treatment liquid film 120 will be described.
FIG. 14 is a graph showing temporal changes in the thickness of the pre-drying treatment liquid film 120 on the upper surface of the substrate W until the sublimable solid 121 is deposited from the pre-drying treatment liquid. The inset in FIG. 14 has a different aspect ratio than the rest of FIG.
A plurality of curves (a solid line curve, a dashed line curve, and a dashed line curve) in FIG. 14 are film thickness curves showing measured values when using a plurality of drying pretreatment liquids having different sublimation substance concentrations. . The conditions for each measurement were the same except for the concentration of the sublimable substance. As shown in FIG. 14, regardless of the concentration of the sublimable substance, when the solid 121 of the sublimable substance is deposited from the pre-drying treatment liquid, the thickness of the pre-drying treatment liquid film 120 increases with the passage of time. decreases with

In FIG. 14, the thickness of the pre-drying treatment liquid film 120 is measured only up to time T1. This is because the sublimable solid 121 precipitated at time T1. In other words, while the pre-drying treatment liquid is transparent, the transparency of the sublimable solid 121 is lower than the transparency of the pre-drying treatment liquid. Therefore, when the sublimable solid 121 precipitates, the value detected by the film thickness measurement unit 91 changes significantly, and the thickness of the pre-drying treatment liquid film 120 cannot be measured.

When the solid sublimation substance 121 precipitates, the value detected by the film thickness measurement unit 91 changes significantly. It can be determined whether or not it has precipitated. Further, the thickness of the dry pretreatment liquid film 120 immediately before the solid sublimation substance 121 precipitates is substantially equal to the thickness of the solid sublimation substance 121 immediately after the solid sublimation substance 121 precipitates. Therefore, by measuring the thickness of the pre-drying treatment liquid film 120 , the controller 3 can also measure the thickness of the sublimable substance solid 121 .

Further, as shown in FIG. 14, the film thickness of the pre-drying treatment liquid rapidly decreased and then gradually decreased regardless of the concentration of the sublimable substance. During the period in which the thickness of the pre-drying treatment liquid film 120 is rapidly reduced, there is almost no difference in the thickness of the pre-drying treatment liquid film 120 and the film thickness reduction rate among a plurality of pre-drying treatment liquids having different sublimation substance concentrations. do not have. That is, if the elapsed time is the same, the thickness of the pre-drying treatment liquid film 120 decreases at approximately the same rate of decrease regardless of the concentration of the sublimable substance.

On the other hand, as shown in the inset in FIG. 14, during the period in which the thickness of the pre-drying treatment liquid film 120 is gradually decreasing, the film thickness reduction speed A difference is seen in the pretreatment liquid. It is considered that this is because the viscosity of the pre-drying treatment liquid changes when the concentration of the sublimable substance changes.
Specifically, the higher the concentration of the sublimable substance in the pre-drying treatment liquid, the higher the viscosity of the pre-drying treatment liquid. The higher the viscosity of the pre-drying treatment liquid, the more difficult it is to be discharged to the outside of the substrate W due to the centrifugal force due to the rotation of the substrate W. Therefore, the higher the concentration of the sublimable substance in the pre-drying treatment liquid, the smaller the slope of the graph. That is, the higher the concentration of the sublimable substance in the pre-drying treatment liquid, the lower the film thickness reduction rate during the period in which the thickness of the pre-drying treatment liquid film 120 is gradually reduced. Therefore, in the inset of FIG. 14, the concentration of the sublimable substance in the pre-drying treatment liquid indicated by the solid line is the lowest, the concentration of the sublimable substance in the pre-drying treatment liquid indicated by the dashed line is the second lowest, and the one-dot chain line indicates The concentration of the sublimable substance in the drying pretreatment liquid shown is the highest. That is, there is a correlation between the film thickness reduction rate and the concentration of the sublimable substance in the pre-drying treatment liquid.

Therefore, if the thickness reduction rates of a plurality of pre-drying treatment liquid films 120 having different sublimation substance concentrations are measured in advance and prepared as reference data SD, the thickness of the pre-drying treatment liquid film 120 on the substrate W is By monitoring , the concentration of the sublimable substance in the pre-drying treatment liquid on the substrate W can be estimated based on the film thickness reduction rate. The reference data SD is stored, for example, in the main storage device 3c of the controller 3 (see FIG. 8). The reference data SD stored in the main storage device 3c is referred to at any time for comparison with the thickness reduction rate obtained by monitoring the thickness of the pre-drying treatment liquid film 120 on the substrate W during substrate processing.

If the thickness of the pre-drying pretreatment liquid film 120 before deposition of the sublimable substance solid 121 is the same, the thickness of the sublimable substance solid 121 increases as the concentration of the sublimable substance increases. It decreases with decreasing concentration of the substance. Therefore, by measuring the thickness of the pre-drying treatment liquid film 120 and estimating the actual concentration of the sublimable substance, the thickness of the solid sublimable substance 121 is estimated before the solid sublimable substance 121 precipitates. can.

FIG. 15 is a flow chart showing a first example flow of the film thickness monitoring process. In the following, reference is made to FIGS. 2 and 15. FIG. The film thickness monitoring step is executed in parallel with the first deposition step (step S7), for example (see FIG. 9). That is, the film thickness monitoring step is performed only when the sublimable solid 121 is deposited first.
When starting to measure the thickness of the pre-drying treatment liquid film 120, the controller 3 determines whether or not the first deposition step (deposition step) has started (step S21 in FIG. 15). Whether or not the first deposition step has started is determined based on, for example, whether the pre-drying treatment liquid valve 41 is open, that is, whether the discharge of the pre-drying treatment liquid is stopped. will be

When the first deposition process has not started (No in step S21 of FIG. 15), that is, when the discharge of the pre-drying treatment liquid is stopped, the controller 3 starts the first deposition process after a predetermined time has elapsed. It is determined whether or not it is set (step S21 in FIG. 15). If the first deposition step has started (Yes in step S21 of FIG. 15), that is, if the discharge of the pre-drying treatment liquid has been stopped, the controller 3 instructs the film thickness measurement unit 91 to supply the pre-drying treatment liquid. Film thickness measurement is started (film thickness measurement step, step S22 in FIG. 15).

While the film thickness measurement unit 91 is measuring the thickness of the pre-drying treatment liquid film 120, the controller 3 also measures the thickness reduction rate of the pre-drying treatment liquid film 120 based on the thickness of the pre-drying treatment liquid film 120. (Thickness reduction rate measurement step).
A reference speed range representing an appropriate film thickness reduction rate range is specified in the recipe based on a reference concentration range representing an appropriate concentration of the sublimable substance in the liquid film of the pre-drying treatment liquid and the reference data SD. . The controller 3 determines whether the film thickness reduction rate is appropriate, that is, whether the film thickness reduction rate is within the reference rate range before the concentration of the sublimable substance in the pre-drying treatment liquid film 120 reaches the saturation concentration. It is determined whether or not (decreasing speed determination step, step S23 in FIG. 15). As a result, it is possible to substantially determine whether or not the solid concentration of the sublimable substance in the pre-drying treatment liquid film 120 is within the reference concentration range (concentration determination step).

If the film thickness reduction rate is appropriate, that is, if the film thickness reduction rate is equal to or higher than the lower limit value of the reference speed range and equal to or lower than the upper limit value of the reference speed range (Yes in step S23 of FIG. 15), the controller 3 determines whether or not the solid sublimation substance 121 is deposited in the first deposition step (step S8 in FIG. 9) in which the solid sublimation substance 121 is deposited first, based on the detection value of the film thickness measurement unit 91. (step S24 in FIG. 15). If the solid sublimation substance 121 has not precipitated (No in step S24 of FIG. 15), the controller 3 determines again whether or not the rate of decrease in film thickness is appropriate after a predetermined period of time has passed (FIG. 15). step S23).

If the sublimable substance solid 121 has precipitated (Yes in step S24 of FIG. 15), the controller 3 controls the sublimable substance in the pre-drying treatment liquid film 120 immediately before the sublimable substance solid 121 precipitates. It is determined whether the thickness of the sublimable solid 121 is appropriate based on the measurement value of the film thickness measurement unit 91 when the concentration of has reached the saturation concentration. That is, the controller 3 determines whether or not the thickness of the sublimable solid 121 exceeds the lower limit value of the reference thickness range and is less than the upper limit value of the reference thickness range (thickness determination step, in FIG. 15). step S25).

If the thickness of the sublimable substance solid 121 is appropriate (Yes in step S25 in FIG. 15), the controller 3 causes the film thickness measurement unit 91 to stop measuring the thickness of the pre-drying treatment liquid film 120 (see FIG. 15). step S26). If the thickness of the sublimable substance solid 121 is not appropriate (No in step S25 of FIG. 15), the controller 3 causes the alarm device 100C (see FIG. 8) to generate an alarm (second abnormality notification step, FIG. 15 step S27). After that, the measurement of the thickness of the pre-drying treatment liquid film 120 by the film thickness measurement unit 91 is stopped (step S26 in FIG. 15).

Due to some cause such as a failure of the first flow control valve 107A or the second flow control valve 107B (see FIG. 7), the concentration of the sublimation substance is outside the standard concentration range, and the film thickness reduction speed is outside the standard speed range. If it is larger than the upper limit or if the film thickness reduction rate is smaller than the lower limit of the reference speed range (No in step S23 of FIG. 15), the controller 3 causes the alarm device 100C (see FIG. 8) to generate an alarm (see FIG. 8). First abnormality notification step, step S28 in FIG. 15).

After that, the controller 3 starts the pre-drying treatment liquid removing step of removing the pre-drying treatment liquid from the upper surface of the substrate W before the solid 121 of the sublimation substance precipitates (step S29 in FIG. 15). The details of the pre-drying treatment liquid removing step will be described later. Then, the controller 3 causes the film thickness measurement unit 91 to stop measuring the film thickness of the pre-drying treatment liquid (step S26 in FIG. 15).
If the substrate processing is not interrupted, the first dissolving step (step S8 in FIG. 9) is started after the first deposition step (step S7 in FIG. 9) and the film thickness monitoring step are performed. When the pre-drying treatment liquid is a solution of the sublimable substance and IPA, the heating of the substrate W is started in order to dissolve the deposited solid 121 of the sublimable substance in the pre-drying treatment liquid. After the first precipitation step and the first dissolution step are repeated a predetermined number of times, the final precipitation step is performed, and finally the sublimation step is performed. When N=0 in FIG. 9, the final precipitation step is performed without repeating the first precipitation step and the first dissolution step, and finally the sublimation step is performed.

That is, when it is determined in the concentration determination step that the concentration of the sublimable substance in the pre-drying treatment liquid film 120 is within the reference concentration range, the sublimation step is performed after the final precipitation step.
FIG. 16 is a schematic diagram for explaining an example of the pre-drying treatment liquid removing process in the first example of the film thickness monitoring process.
As described above, the controller 3 measures the rate of decrease in the thickness of the pre-drying treatment liquid film 120 in order to determine whether the concentration of the sublimable substance contained in the pre-drying treatment liquid film 120 is appropriate. (Step S23 in FIG. 15). This is because if there is an abnormality in the concentration of the sublimable substance in the pre-drying treatment liquid film 120, that is, if the concentration of the sublimable substance in the pre-drying treatment liquid film 120 is outside the reference concentration range, the final deposition This is because the thickness of the sublimable substance solid 121 deposited in the step (step S9 in FIG. 9) is larger or smaller than the intended value. If the thickness of the sublimable substance solid 121 immediately before sublimation is larger or smaller than the intended value, the collapse rate of the pattern PA may deteriorate.

Therefore, the controller 3 performs the pre-drying treatment liquid removing step (step S29 in FIG. 15) shown in FIG. FIG. 16 shows a state in which the replacement liquid nozzle 43 is discharging the solvent corresponding to the replacement liquid toward the upper surface of the substrate W. As shown in FIG. FIG. 16 shows an example in which the dry pretreatment liquid is a solution of camphor and IPA and the solvent is IPA. When the drying pretreatment liquid is a solution of camphor and methanol, methanol is discharged from the substitution liquid nozzle 43 instead of IPA.

If there is an abnormality in the concentration of the sublimable substance in the pre-drying treatment liquid film 120, the controller 3 may cause the replacement liquid nozzle 43 to eject the solvent, as shown in FIG. In this case, the pre-drying treatment liquid on the substrate W is replaced with the solvent, and a liquid film of the solvent covering the entire upper surface of the substrate W is formed. Therefore, it is possible to remove from the substrate W the pre-drying treatment liquid having an inappropriate concentration of the sublimable substance before the solid 121 of the sublimable substance is deposited. That is, when it is determined in the concentration determining step that the concentration of the sublimable substance in the pre-drying treatment liquid film 120 is not within the reference concentration range, the removal liquid is added before the solid 121 of the sublimable substance is precipitated in the first precipitation step. A pre-drying treatment liquid removing step of removing the pre-drying treatment liquid from the upper surface of the substrate W is performed by supplying the solvent as as to the upper surface of the substrate W. As shown in FIG.

Thus, when the pre-drying treatment liquid is a solution of camphor and IPA, IPA serves as a removal liquid for removing the pre-drying treatment liquid from the upper surface of the substrate W in the pre-drying treatment liquid removing step. When the pre-drying treatment liquid is a solution of camphor and methanol, methanol serves as the removal liquid in the pre-drying treatment liquid removing step. The removal liquid is preferably the same type of liquid as the solvent used in the pre-drying treatment liquid, but is not limited to this. The removing liquid may be a liquid different from the solvent of the pre-drying treatment liquid as long as it is compatible with the pre-drying treatment liquid.

After the controller 3 interrupts the first deposition step and starts the pre-drying treatment liquid removing step (step S29 in FIG. 15), the controller 3 causes the film thickness measurement unit 91 to measure the thickness of the pre-drying treatment liquid film 120. is stopped (step S26 in FIG. 15).
In the substrate processing of this embodiment, the pre-drying treatment liquid remains on the upper surface of the substrate W when the sublimable solid 121 starts to precipitate in the first deposition step. In the first dissolving step, at least part of the sublimable substance solid 121 is dissolved in this drying pretreatment liquid. After that, in the final precipitation step, the solvent is again evaporated from the pre-drying treatment liquid. As a result, the content of the solvent is reduced, and a sublimable solid 121 is deposited on the upper surface of the substrate W. As shown in FIG. Thereafter, the sublimable substance solid 121 is sublimated and removed from the substrate W. FIG. In this manner, the pre-drying treatment liquid is removed from the substrate W, and the substrate W is dried.

Before the sublimable solid 121 is deposited for the first time, the drying pretreatment liquid exists not only between the patterns PA but also above the patterns PA. In a substrate W such as a semiconductor wafer or an FPD substrate, the interval G1 between the patterns PA is narrow. When the interval G1 between the patterns PA is narrow, the pre-drying treatment liquid between the patterns PA is in the bulk of the pre-drying treatment liquid, that is, in the range from the surface (upper surface) of the pre-drying treatment liquid film 120 to the upper surface of the pattern PA. It differs in properties from the drying pretreatment liquid located. The difference between the two properties becomes more pronounced as the interval G1 between the patterns PA becomes narrower.

When the interval G1 of the pattern PA is narrow, when the sublimable solid 121 is deposited first, the sublimable solid 121 is deposited only in the bulk of the drying pretreatment liquid, and the sublimable solid 121 is deposited in the pattern. A non-existent or almost non-existent under-deposited region between the PAs may form in the top surface of the substrate W. In this case, the surface tension of the dry pretreatment liquid between the patterns PA is applied to the side surfaces of the pattern PA, so the pattern PA in the incompletely precipitated region may collapse when sublimating the solid 121 of the sublimable substance. . This causes an increase (worsening) in the collapse rate of the pattern PA.

On the other hand, when the precipitated sublimable substance solid 121 is dissolved in the pre-drying treatment liquid, and then the sublimable substance solid 121 is precipitated again, sublimation is possible even in a narrow space such as the space between the patterns PA. Crystal nuclei of a solid 121 of matter are formed. Therefore, by dissolving the deposited sublimable substance solid 121 in the pre-drying treatment liquid and then depositing the sublimable substance solid 121 again, even if the interval G1 of the pattern PA is narrow, incomplete deposition can occur. It is possible to prevent the generation of the area or reduce the area. Thereby, the collapse rate of the pattern PA can be reduced.

The thickness of the sublimable substance solid 121 is substantially the same as the thickness of the dry pretreatment liquid film 120 when the saturated concentration of the sublimable substance is reached. When the concentration of the sublimable substance in the dry pretreatment liquid film 120 reaches the saturation concentration of the sublimable substance, the sublimable substance solid 121 precipitates immediately after that. Therefore, if the concentration of the sublimable substance in the pre-drying treatment liquid film 120 can be known before the concentration of the sublimable substance in the pre-drying treatment liquid film 120 reaches the saturation concentration of the sublimable substance, The thickness of the solid 121 can be predicted and the formation of an improperly thick sublimable solid 121 can be avoided.

Generally, in order to measure the concentration of a substance in a liquid, it is necessary to bring a concentration measuring instrument (not shown) into contact with the liquid. Since the pre-drying treatment liquid film 120 formed on the substrate W is relatively thin, it is difficult to contact the pre-drying treatment liquid film 120 without contacting the upper surface of the substrate W with a device for measuring the concentration. Therefore, the pattern PA formed on the upper surface of the substrate may be damaged.

As described above, the inventors of the present application have found that there is a correlation between the film thickness reduction rate and the concentration of the sublimable substance in the pre-drying treatment liquid film 120 . In the present embodiment, the sublimable substance in the pre-drying treatment liquid film 120 is determined based on the film thickness reduction rate of the pre-drying treatment liquid film 120 before the sublimable substance solid 121 precipitates in the first deposition step. is within the reference density range (density determination step).

Specifically, the thickness reduction rate of the pre-drying treatment liquid film 120 in the first deposition step can be measured by continuously measuring the thickness of the pre-drying treatment liquid film 120 by the film thickness measurement unit 91 for a predetermined time. Therefore, the controller 3 determines whether or not the film thickness reduction speed measured by the film thickness measurement unit 91 is within the reference speed range, thereby substantially reducing the amount of the sublimable substance in the pre-drying treatment liquid film 120. It can be determined whether the density is within the reference density range. This makes it possible to determine whether or not the concentration of the sublimable substance in the dry pretreatment liquid film 120 is within the reference concentration range while avoiding difficult measurements.

Since the amount of solvent that evaporates in the first dissolving step and the final precipitation step is predictable, even if the concentration determination step is performed in the first precipitation step, the drying pretreatment liquid during the first precipitation step It is possible to determine whether the thickness of the sublimable substance solid 121 formed on the upper surface of the substrate W is appropriate based on the concentration of the sublimable substance in the film 120 .
Therefore, when it is determined that the concentration of the sublimable substance in the pre-drying treatment liquid film 120 is within the reference concentration range, the sublimable substance solid 121 having an appropriate thickness is formed after the final precipitation step is completed. . Therefore, if the substrate processing is continued to sublimate the solid 121 of the sublimable substance, the collapsing rate of the pattern PA on the upper surface of the substrate W can be reduced.

On the other hand, when it is determined that the concentration of the sublimable substance in the pre-drying treatment liquid film 120 is not within the reference concentration range, the removing liquid sublimates from the upper surface of the substrate W before the solid 121 of the sublimable substance precipitates. substances can be removed (pre-drying treatment liquid removal step). As a result, it is possible to prevent the sublimable solid 121 having an inappropriate thickness from being formed on the upper surface of the substrate W in advance. Therefore, it is possible to suppress an increase in the collapse rate of the pattern PA. Further, even if it is determined that the concentration of the sublimable substance in the pre-drying treatment liquid film 120 is not within the reference concentration range, the pre-drying treatment liquid on the upper surface of the substrate W is removed. Therefore, the substrate W can be reused.

Further, in this embodiment, the concentration of the sublimable substance in the pre-drying pretreatment liquid film 120 is estimated by comparing the reference data SD with the film thickness reduction rate measured during the first deposition step. Therefore, the concentration of the sublimable substance in the pre-drying treatment liquid film 120 can be easily estimated during the first precipitation step.
Further, in the present embodiment, when it is determined in the concentration determining step that the concentration of the sublimable substance in the pre-drying treatment liquid film 120 is not within the reference concentration range, an abnormality is notified to the operator (second 1 anomaly notification process). Therefore, the operator can determine at appropriate timing whether or not to continue the substrate processing based on the notification of the abnormality.

Further, in the present embodiment, the thickness of the pre-drying treatment liquid film 120 is measured by the film thickness measurement unit 91 immediately before the solid 121 of the sublimation substance is precipitated by evaporation of the solvent (film thickness measurement step). Then, the controller 3 determines whether or not the thickness of the pre-drying treatment liquid film 120 measured in the film thickness measurement process is within the reference thickness range of the sublimable solid 121 (thickness determination process).

Therefore, whether the thickness of the pre-drying treatment liquid film 120 when the concentration of the sublimation substance in the pre-drying treatment liquid film 120 reaches the saturation concentration of the sublimation substance is within the reference thickness range of the solid 121 of the sublimation substance. By determining whether or not, it is possible to determine whether or not the thickness of the sublimable substance solid 121 formed on the upper surface of the substrate W is appropriate.
If the thickness of the sublimable solid 121 formed on the upper surface of the substrate W is appropriate, the appropriate thickness of the sublimable solid 121 is formed after the final deposition step is completed. Therefore, if the substrate processing is continued to sublimate the solid 121 of the sublimable substance, it is possible to obtain the substrate W in which the collapse rate of the pattern PA is reduced.

On the other hand, when the thickness of the solid sublimation substance 121 formed on the upper surface of the substrate W is not appropriate, the substrate processing is interrupted, thereby suppressing the generation of the substrate W in which the collapse rate of the pattern PA is increased.
In the present embodiment, when the film thickness measured in the film thickness measuring step is determined not to be within the reference thickness range in the thickness determining step, an abnormality is notified to the operator (second abnormality notifying step). . Therefore, the operator can determine at appropriate timing whether or not to continue the substrate processing based on the notification of the abnormality.

In the present embodiment, in the first precipitation step, instead of evaporating the solvent from the pre-drying treatment liquid by heating the pre-drying treatment liquid, while maintaining the temperature of the pre-drying treatment liquid at room temperature or lower, Evaporate the solvent. In this case, the concentration of the sublimable substance locally increases on the surface of the pre-drying treatment liquid, and solid 121 of the sublimable substance precipitates on or near the surface of the pre-drying treatment liquid (room temperature precipitation step). At the same time, the dry pretreatment liquid remains between the sublimable substance solid 121 and the upper surface of the pattern PA. The sublimable substance solid 121 dissolves in this drying pretreatment liquid.

On the other hand, in the first deposition step, when the pre-drying treatment liquid is heated to evaporate the solvent from the pre-drying treatment liquid, the temperature of the pre-drying treatment liquid rises to a value higher than room temperature, and the pre-drying treatment liquid The concentration of sublimable substances in increases. After increasing the concentration of the sublimable substance, if the sublimable substance solid 121 is precipitated by natural cooling or forced cooling of the drying pretreatment liquid, most or all of the bulk of the drying pretreatment liquid becomes the sublimable substance solid. may change to 121.

If the pre-drying treatment liquid does not remain above the pattern PA, the sublimable substance solid 121 will not efficiently dissolve in the pre-drying treatment liquid. Even if the dry pretreatment liquid remains between the patterns PA, the efficiency of dissolving the sublimable substance solid 121 in the dry pretreatment liquid between the patterns PA is the same as the bulk of the dry pretreatment liquid. The efficiency of dissolving 121 is inferior. Therefore, by maintaining a portion of the bulk of the pre-drying treatment liquid in the liquid state, the sublimable solid 121 can be efficiently dissolved in the pre-drying treatment liquid.

Further, in the present embodiment, in the first dissolving step, the pre-drying treatment liquid on the upper surface of the substrate W is heated to raise the temperature of the pre-drying treatment liquid to a value higher than room temperature. The dissolution of the sublimable substance solid 121 in the pre-drying treatment liquid is promoted by the temperature rise of the pre-drying treatment liquid. Thereby, the solid 121 of the sublimable substance can be efficiently dissolved in the pre-drying treatment liquid. Furthermore, since the forcible melting of the sublimable solid 121 starts with the start of heating, by changing the timing of starting heating, the sublimable solid 121 can be forcibly melted at an arbitrary time. can initiate rapid dissolution.

Further, in the present embodiment, in the first dissolving step, the sublimable solid 121 and the pre-drying treatment liquid are not directly heated from above the substrate W, but are indirectly heated via the substrate W. (Indirect heating step). When the sublimable substance solid 121 and the pre-drying treatment liquid are heated from above the substrate W, part of the sublimable substance solid 121 on the surface of the pre-drying treatment liquid may sublimate. In this case, part of the sublimable material is wasted, and the thickness of the final sublimable material solid 121 becomes smaller than the intended value. By heating the solid 121 of the sublimable substance and the pre-drying treatment liquid through the substrate W, such disappearance of the sublimable substance can be reduced.

Further, in the present embodiment, in order to deposit the sublimable solid 121 on the substrate W in the final deposition step, the pre-drying treatment liquid is heated while the solvent is evaporated from the pre-drying treatment liquid. As a result, a sublimable solid 121 is precipitated from the high-temperature pretreatment liquid for drying. The saturation concentration of the sublimable substance in the pre-drying treatment liquid increases as the temperature of the pre-drying treatment liquid rises. The ratio of the solvent contained in the sublimable substance solid 121 decreases as the saturation concentration of the sublimable substance increases. When the solid 121 of the sublimable substance is sublimated, the solvent contained in the solid 121 of the sublimable substance can generate a collapsing force that collapses the pattern PA. Therefore, by reducing the solvent content, the collapse rate of the pattern PA can be further reduced.

Further, in the present embodiment, in the first deposition step, the sublimable substance solid 121 is deposited on the surface of the pre-drying treatment liquid film 120 (liquid surface deposition step). When the solvent evaporates from the pre-drying treatment liquid, the heat of the pre-drying treatment liquid corresponding to the heat of vaporization is released into the atmosphere together with the solvent, and the temperature of the surface of the pre-drying treatment liquid decreases. When the sublimable solid 121 is formed, less solvent evaporates from the pre-drying liquid, and thus less heat is released from the pre-drying liquid into the atmosphere. At the same time, heat in the atmosphere is transferred to the pre-drying liquid through the sublimable solid 121 . As a result, the temperature of the interface between the sublimable solid 121 and the pre-drying treatment liquid rises. Therefore, the sublimable substance solid 121 can be dissolved in the pre-drying treatment liquid without forcibly heating the pre-drying treatment liquid on the substrate W (natural dissolution step).

The film thickness monitoring process is not limited to the flowchart shown in FIG. For example, FIG. 17 shows a flow chart showing the flow of a second example of the film thickness monitoring process. FIG. 20, which will be described later, shows a flowchart showing the flow of a third example of the film thickness monitoring process. FIG. 22, which will be described later, shows a flowchart showing the flow of a fourth example of the film thickness monitoring process.
The film thickness monitoring process of the second example shown in FIG. 17 differs from the film thickness monitoring process of the first example (see FIG. 15) in that the concentration of the sublimable substance in the pre-drying treatment liquid film 120 is within the reference concentration range. and when the concentration of the sublimable substance in the pre-drying treatment liquid film 120 is lower than the lower limit of the reference concentration range, different processes are started.

In the film thickness monitoring process of the second example, when the film thickness reduction rate is larger than the upper limit value of the reference speed range or when the film thickness reduction speed is smaller than the lower limit value of the reference speed range (at step S23 in FIG. 17 No), the controller 3 causes the alarm device 100C (see FIG. 8) to generate an alarm (first abnormality notification step, step S28 in FIG. 17). After that, the controller 3 determines whether or not the film thickness reduction speed is smaller than the lower limit of the reference speed range (step S31 in FIG. 17).

If the film thickness reduction rate is smaller than the lower limit of the reference rate range (Yes in step S31 of FIG. 17), that is, the concentration of the sublimable substance in the pre-drying treatment liquid film 120 is higher than the upper limit of the reference concentration range. In this case, the controller 3 starts a solvent evaporation suppression process for suppressing evaporation of the solvent from the liquid film on the substrate W (step S32 in FIG. 17). As a result, the concentration of the sublimable substance in the pre-drying treatment liquid film 120 is reduced and adjusted within the reference concentration range.

On the other hand, if the film thickness reduction rate is greater than the upper limit of the reference rate range (No in step S31 in FIG. 17), that is, the concentration of the sublimation substance in the pre-drying treatment liquid film 120 is higher than the lower limit of the reference concentration range. is also low, the controller 3 starts a solvent evaporation promotion process for promoting evaporation of the solvent from the pre-drying treatment liquid film 120 (step S33 in FIG. 17). As a result, the concentration of the sublimable substance in the pre-drying treatment liquid film 120 is increased and adjusted within the reference concentration range.

After the solvent evaporation suppression process or the solvent evaporation promotion process is started, the controller 3 causes the film thickness measurement unit 91 to measure the thickness of the pre-drying treatment liquid film 120 in the same manner as in the first example of the film thickness monitoring process shown in FIG. is stopped (step S26 in FIG. 17).
FIG. 18 is a schematic diagram for explaining an example of the solvent evaporation suppression step. In the solvent evaporation suppression step, for example, solvent mist or vapor is supplied to the space between the upper surface of the substrate W and the lower surface 51L of the blocking member 51 . In FIG. 18, the dry pretreatment liquid is a solution of camphor and IPA, and the space between the upper surface of the substrate W and the lower surface 51L of the blocking member 51 is filled with nitrogen gas containing IPA mist or vapor. shows an example. When the drying pretreatment liquid is a solution of camphor and methanol, nitrogen gas containing mist or vapor of methanol is discharged toward the upper surface of the substrate W. As shown in FIG. Nitrogen gas represents a carrier gas that carries the solvent mist or vapor towards the substrate W. FIG.

When discharging toward the space between the upper surface of the substrate W and the lower surface 51L of the blocking member 51, nitrogen gas may be supplied into the IPA (liquid) in the tank (so-called bubbling). In this way, a large number of nitrogen gas bubbles are formed in the IPA and the nitrogen gas containing IPA mist or vapor is released from the surface of the IPA in the tank. This nitrogen gas may be discharged to at least one of the central nozzle 55 and the upper central opening 61 of the blocking member 51 .

When solvent mist or vapor is supplied to the space between the upper surface of the substrate W and the lower surface 51L of the blocking member 51, the vapor pressure of the solvent in the atmosphere in contact with the pre-drying treatment liquid film 120 increases. Therefore, evaporation of the solvent from the pre-drying treatment liquid film 120 is suppressed. On the other hand, since the vapor pressure of the sublimable substance in the atmosphere does not change, the sublimable substance evaporates from the pre-drying treatment liquid, albeit in a very small amount. Therefore, when the concentration of the sublimable substance is assumed to be higher than the upper limit of the reference concentration range, if mist or vapor of the solvent is supplied to the space between the upper surface of the substrate W and the lower surface 51L of the blocking member 51, The concentration of the sublimable substance in the pre-drying treatment liquid film 120 can be set within the reference concentration range, and the sublimable substance solid 121 can be deposited with an intended thickness.

FIG. 19 is a schematic diagram for explaining an example of the solvent evaporation promotion step. In the solvent evaporation acceleration step, for example, a gas such as nitrogen gas that does not contain IPA mist or vapor is supplied to the space between the upper surface of the substrate W and the lower surface 51L of the blocking member 51 . The controller 3 may cause the central nozzle 55 to discharge nitrogen gas, or may cause the upper central opening 61 of the blocking member 51 to discharge nitrogen gas. If the center nozzle 55 is already discharging nitrogen gas, the controller 3 may increase the opening of the flow control valve 58 (see FIG. 2). When the upper central opening 61 of the blocking member 51 is already discharging nitrogen gas, the controller 3 may increase the opening degree of the flow control valve 65 (see FIG. 2).

When the nitrogen gas is supplied to the space between the upper surface of the substrate W and the lower surface 51L of the blocking member 51, the vapor pressure of the solvent in the atmosphere in contact with the pre-drying treatment liquid film 120 decreases. Therefore, evaporation of the solvent from the pre-drying treatment liquid is promoted. Strictly speaking, the vapor pressure of the sublimable substance in the atmosphere also decreases, although by a very small amount. However, since the vapor pressure of the sublimable substance is much lower than the vapor pressure of the solvent, mainly the solvent evaporates from the drying pretreatment liquid. Therefore, the concentration of the sublimable substance in the pre-drying treatment liquid film 120 can be kept within the reference concentration range, and the solid substance 121 of the sublimable substance can be deposited with an intended thickness.

Since the nitrogen gas discharged from the central nozzle 55 and the upper central opening 61 of the blocking member 51 promotes deposition of the sublimable substance solid 121, the central nozzle 55 and the upper central opening 61 of the blocking member 51 are effective for solvent evaporation. functioning as a unit.
The concentration of the sublimable substance in the pre-drying treatment liquid film 120 is determined by comparing the film thickness reduction rate immediately before executing the solvent evaporation suppression process or the solvent evaporation promotion process with the film thickness reduction rate included in the reference data SD. It is possible to calculate the amount of evaporation of the solvent from the pre-drying treatment liquid film 120 in order to make the concentration within the reference concentration range. If the solvent evaporation suppression step or the solvent evaporation promotion step is executed so that the evaporation amount of the solvent becomes an appropriate evaporation amount, the thickness of the liquid film 120 of the pre-drying treatment liquid when the concentration of the sublimable substance reaches the saturation concentration is reduced. can be easily adjusted to an appropriate thickness. As a result, a sublimable solid 121 having an appropriate thickness can be deposited.

In the second example of the film thickness monitoring process, when it is determined in the concentration determination process that the concentration of the sublimable substance in the pre-drying treatment liquid film 120 is higher than the upper limit value of the reference concentration range, the pre-drying treatment liquid film 120 Evaporation of the solvent from the pre-drying treatment liquid film 120 is suppressed by supplying vapor or mist of the solvent to the atmosphere in contact with (solvent evaporation suppression step).
By supplying solvent vapor or mist to the atmosphere in contact with the pre-drying treatment liquid film 120, the amount of solvent (vapor pressure of the solvent) present in the atmosphere in contact with the pre-drying treatment liquid film 120 is increased. Thereby, evaporation of the solvent from the pre-drying treatment liquid film 120 can be suppressed. When the evaporation of the solvent from the pre-drying treatment liquid film 120 is suppressed, the proportion of sublimable substances in the substances evaporated from the pre-drying treatment liquid film 120 increases. Therefore, the concentration of the sublimable substance in the pre-drying treatment liquid film 120 is reduced. Thereby, the concentration of the sublimable substance in the pre-drying treatment liquid film 120 can be adjusted within the reference concentration range.

Therefore, even if it is determined in the concentration determination step that the concentration of the sublimable substance in the pre-drying treatment liquid film 120 is higher than the upper limit value of the reference concentration range, the solvent evaporation suppression step is executed. A substrate W with a reduced collapse rate of PA can be obtained.
Further, in the second example of the film thickness monitoring process, when it is determined in the concentration determining process that the concentration of the sublimable substance in the pre-drying treatment liquid film 120 is lower than the lower limit of the reference concentration range, the first precipitation process is accelerated to evaporate the solvent from the pre-drying treatment liquid film 120 by supplying an inert gas toward the atmosphere in contact with the drying pre-treatment liquid film 120 (solvent evaporation promotion step).

By accelerating the evaporation of the solvent from the pre-drying pretreatment liquid film 120, the concentration of the sublimable substance in the pre-drying pretreatment liquid film 120 is increased. Thereby, the concentration of the sublimable substance in the pre-drying treatment liquid film 120 can be adjusted within the reference concentration range. Therefore, even if it is determined in the concentration determination step that the concentration of the sublimable substance in the pre-drying treatment liquid film 120 is lower than the lower limit value of the reference concentration range, the solvent evaporation promotion step is executed. A substrate W with a reduced collapse rate of PA can be obtained.

The third example of the film thickness monitoring process shown in FIG. 20 differs from the second example of the film thickness monitoring process (see FIG. 17) in that the film thickness reduction rate is smaller than the lower limit of the reference rate range (see FIG. 17). 20), that is, if the concentration of the sublimable substance in the pre-drying treatment liquid film 120 is higher than the upper limit value of the reference concentration range, the controller 3 controls the pre-drying treatment liquid film on the substrate W This is the point at which the thinning process for thinning 120 is started (step S34 in FIG. 20).

If the film thickness reduction rate is greater than the upper limit of the reference rate range (No in step S31 of FIG. 20), that is, the concentration of the sublimation substance in the pre-drying treatment liquid film 120 is lower than the lower limit of the reference concentration range. In this case, the controller 3 starts the solvent evaporation promotion step (step S33 in FIG. 20), as in the second example of the film thickness monitoring step.
In the thinning process, the controller 3 causes the spin motor 14 to accelerate the rotation of the substrate W. FIG. As a result, the centrifugal force acting on the pre-drying treatment liquid film 120 on the substrate W is increased, and the amount of the pre-drying treatment liquid discharged to the outside of the substrate W is increased.

21A and 21B are schematic diagrams for explaining the thinning process. 21A shows the state before the rotation of the substrate W is accelerated, and FIG. 21B shows the state after the rotation of the substrate W is accelerated. Specifically, the rotation speed of the substrate W is changed from the first deposition speed (eg, 500 rpm) to a thinning speed (eg, 1500 rpm) that is higher than the first deposition speed.

When the concentration of the sublimable substance in the pre-drying treatment liquid film 120 is higher than the upper limit of the reference concentration range, the thickness of the sublimable substance solid 121 immediately before sublimation becomes larger than the intended value. When the thickness of the dry pretreatment liquid film 120 on the substrate W is reduced, the amount of the sublimable substance contained in the dry pretreatment liquid film 120 is reduced, so the thickness of the sublimable substance solid 121 is also reduced.
Therefore, in the third example of the film thickness monitoring process, when the concentration of the sublimable substance in the pre-drying treatment liquid film 120 is higher than the upper limit value of the reference concentration range, the rotation speed of the substrate W is increased to perform the pre-drying treatment. By exerting centrifugal force on the liquid film 120, the thickness of the pre-drying treatment liquid film 120 is reduced before the sublimable substance solid 121 is precipitated. As a result, the thickness of the sublimable substance solid 121 formed on the upper surface of the substrate W can be reduced, and the sublimable substance solid 121 having an intended thickness can be deposited. Therefore, even if it is determined in the concentration determining step that the concentration of the sublimable substance in the pre-drying treatment liquid film 120 is higher than the upper limit value of the reference concentration range, the thinning step is executed. It is possible to obtain a substrate W with a reduced collapse rate.

If the dry pretreatment liquid is a solution of camphor and IPA, it is also possible to carry out the fourth example of the film thickness monitoring process shown in FIG. The fourth example of the film thickness monitoring process differs from the first example of the film thickness monitoring process (see FIG. 15) in that the thickness of the sublimable solid 121 is determined to be within the reference thickness range (see FIG. 15). 22 (Yes in step S25), the controller 3 is to start the first melting step (step S45 in FIG. 22). That is, the controller 3 starts supplying the heating liquid such as hot water to the lower surface of the substrate W, and starts heating the liquid film of the pre-drying treatment liquid on the upper surface of the substrate W through the substrate W. FIG. Thereafter, the film thickness measurement unit 91 is caused to stop measuring the film thickness of the pre-drying treatment liquid (step S26 in FIG. 22).

In a fourth example of the film thickness monitoring process, the first dissolution process is triggered by the formation of a sublimable substance solid 121 having an appropriate thickness. Therefore, the first dissolution step, the final precipitation step, and the sublimation step are performed only when a sublimable substance solid 121 of appropriate thickness is formed. After the sublimation process is completed, a substrate W in which the collapse rate of the pattern PA is reduced can be obtained. If the sublimable substance solid 121 having an appropriate thickness is not formed, the substrate is processed without executing the steps after the first deposition step (the first dissolution step, the final deposition step, and the sublimation step). can be discontinued early.

If the time from the deposition of the sublimable solid 121 to the sublimation is short, before the sublimable solid 121 is dissolved in the pre-drying treatment liquid, that is, before the heating of the pre-drying treatment liquid is started. , some or all of the sublimable solid 121 may sublimate. Even in such a case, by monitoring whether or not the sublimable solid 121 has precipitated, it is possible to start heating the pre-drying treatment liquid at an optimum time, and to reduce the unintended sublimation of the sublimable solid 121. be able to.

The present invention is not limited to the contents of the above-described embodiments, and various modifications are possible.
As described above, in the substrate processing described above, the film thickness monitoring step is executed in parallel with the first deposition step (step S7). However, if the dry pretreatment liquid is a solution of camphor and IPA, monitoring the thickness of the dry pretreatment liquid film may be performed each time the sublimable solid 121 is deposited.

Moreover, when the pre-drying treatment liquid is a solution of camphor and IPA, the thickness of the pre-drying treatment liquid film 120 is monitored as indicated by the two-dot chain line in FIG. It may be done in parallel. That is, when the pre-drying treatment liquid is a solution of camphor and IPA, in parallel with at least one of the first precipitation step (step S7 in FIG. 9) and the final precipitation step (step S9 in FIG. 9), The thickness of membrane 120 may be monitored.

Unlike the substrate processing according to the above-described embodiment (see FIG. 9), as shown in FIG. Sublimation substrate treatments are also feasible.
In the substrate processing of FIG. 23, after the film thickness reduction step (step S6), a deposition step (step S50) of depositing a solid sublimable substance on the upper surface of the substrate W is performed, and then a sublimation step (step S10) is performed. executed. Then, in parallel with the deposition step (step S50), the film thickness monitoring step of any one of the first to third examples is performed.

In the first deposition step (step S7 in FIG. 9) for first depositing the sublimable substance solid 121, the pre-drying treatment liquid film 120 is heated at a heating temperature higher than room temperature instead of being maintained at a temperature below room temperature. Meanwhile, the solvent may be evaporated from the pre-drying treatment liquid on the substrate W.
In the final deposition step (step S9 in FIG. 9) of the first substrate processing example, while heating the pre-drying treatment liquid on the substrate W, instead of evaporating the solvent from the pre-drying treatment liquid, the pre-drying treatment liquid on the substrate W is heated. The solvent may be evaporated from the pre-drying treatment liquid while the forced heating of the treatment liquid is stopped.

When dissolving the sublimable substance solid 121 in the pre-drying treatment liquid, instead of supplying hot water, which is an example of a heating liquid having a temperature higher than room temperature, to the lower surface of the substrate W, a heating gas having a temperature higher than room temperature is applied to the substrate. You may discharge toward the upper surface or the lower surface of W. For example, nitrogen gas having a temperature higher than room temperature may be discharged to at least one of the central nozzle 55 and the lower central opening 81 of the spin base 12 . A heating element that generates Joule heat when energized, or a lamp that emits light toward the substrate W may be arranged above or below the substrate W. FIG. For example, a heating element may be built in at least one of spin base 12 and blocking member 51 .

Sublimable solids 121 may be removed in a treatment unit 2 different from the wet treatment unit 2w. The processing unit 2 that removes the sublimable solid 121 may be a part of the substrate processing apparatus 1 or a part of the substrate processing apparatus 1 different from the substrate processing apparatus 1 . That is, the substrate processing apparatus 1 provided with the wet processing unit 2w and the substrate processing apparatus 1 provided with the processing unit 2 for removing the sublimable solid 121 are provided in the same substrate processing system. The substrate W may be transferred from one substrate processing apparatus 1 to another substrate processing apparatus 1 before the solid 121 of the toxic substance is removed.

If the rinsing liquid such as pure water on the substrate W can be replaced with the pre-drying treatment liquid, the pre-drying treatment liquid supplying step is performed without performing the replacement liquid supplying step of replacing the rinsing liquid on the substrate W with the replacement liquid. may
The blocking member 51 may include, in addition to the disc portion 52 , a cylindrical portion extending downward from the outer peripheral portion of the disc portion 52 . In this case, when the blocking member 51 is arranged at the lower position, the substrate W held by the spin chuck 10 is surrounded by the cylindrical portion 25 .

The blocking member 51 may rotate around the rotation axis A<b>1 together with the spin chuck 10 . For example, the blocking member 51 may be placed on the spin base 12 so as not to contact the substrate W. FIG. In this case, since the blocking member 51 is connected to the spin base 12 , the blocking member 51 rotates in the same direction and at the same speed as the spin base 12 .
The blocking member 51 may be omitted. However, when supplying a liquid such as pure water to the lower surface of the substrate W, it is preferable that the blocking member 51 is provided. The blocking member 51 can block droplets that have flowed along the outer peripheral surface of the substrate W from the lower surface of the substrate W to the upper surface of the substrate W, and droplets that have rebounded inward from the processing cup 21, so that drying on the substrate W can be prevented. This is because the liquid mixed in the pretreatment liquid can be reduced.

The electric motor 96 of the film thickness measurement unit 91 may be omitted if there is no need to change the incident position of the light of the light emitting element 92 with respect to the upper surface of the substrate W.
When the light from the light-emitting element 92 is incident on the upper surface of the substrate W substantially perpendicularly, the housing 93 of the film thickness measurement unit 91 may accommodate the light-receiving element 97 in addition to the light-emitting element 92 . In this case, the light (reflected light) of the light emitting element 92 reflected by the upper surface of the substrate W passes through the opening of the housing 93 closed with the transparent plate 94 and is received by the light receiving element 97 inside the housing 93 .

When both the light-emitting element 92 and the light-receiving element 97 are accommodated in the housing 93, the controller 3 moves the housing 93 horizontally to determine the incident position at which the light from the light-emitting element 92 is incident on the upper surface of the substrate W. The substrate W may be moved in the radial direction. Specifically, the processing unit 2 is provided with a scan arm that holds the housing 93 above the substrate W held by the spin chuck 10 and an electric actuator that horizontally moves the scan arm within the chamber 4 . good too.

In the above-described embodiment, the film thickness measurement unit 91 cannot measure the liquid film of the pre-drying treatment liquid after the solid 121 of the sublimation substance is deposited. Unlike the above embodiments, a film thickness measurement unit 191 capable of measuring the thickness of the sublimable solid 121 may be used as the film thickness measurement unit (see FIG. 25A). The film thickness measurement unit 191 accommodates the light emitting element 191A and the light receiving element 191B in the same housing 191C. The film thickness measurement unit 191 can be moved, for example, along the radial direction of rotation of the substrate W by a moving unit 192 . Specifically, the processing unit 2 is provided with a scan arm that holds the housing 191C above the substrate W held by the spin chuck 10, and an electric actuator that horizontally moves the scan arm within the chamber 4. good too.

Therefore, the film thickness measurement unit 191 can measure the thickness of the sublimable substance solid 121 (solid film) deposited on the upper surface of the substrate W at a plurality of locations on the upper surface of the substrate W while moving above the substrate W. . A plurality of black points Pi in FIG. 25A indicate incident positions at which the light from the light emitting element 191A is incident on the upper surface of the substrate W. As shown in FIG.
If the film thickness measurement unit 191 is configured to measure the film thickness at a plurality of locations on the upper surface of the substrate W, the fifth example of the film thickness monitoring process shown in FIG. 24 can be executed. The fifth example of the film thickness monitoring process shown in FIG. 24 differs from the first example of the film thickness monitoring process shown in FIG. The flatness measuring step and the flatness determination step of determining whether the surface of the sublimable solid 121 is flat are executed.

Specifically, when the thickness of the sublimable substance solid 121 is appropriate (Yes in step S25 of FIG. 24), the movement of the film thickness measurement unit 191 in the rotational radial direction of the substrate W is started (see FIG. 24 step S51). Thereby, as shown in FIG. 25A, the flatness of the surface of the sublimable solid 121 is measured (flatness measuring step).
The degree of flatness is, for example, the degree of variation in the height position of the surface of the sublimable substance solid 121 measured at a plurality of locations. The height position of the surface of the sublimable solid 121 may be directly measured by the film thickness measurement unit 191, or may be measured by the film thickness measurement unit 191. It may be calculated from the thickness of the sublimable solid 121 . The surface of the solid sublimable substance 121 is flatter as the variation in height position of the surface of the solid sublimable substance 121 measured at a plurality of points is smaller.

Then, it is determined whether or not the surface of the sublimable solid 121 is sufficiently flat (flatness determination step, step S52 in FIG. 24). As a result, it is possible to check whether or not the sublimable substance solid 121 having a uniform thickness is formed over the entire upper surface of the substrate W or not.
Specifically, when the flatness measured in the flatness measuring step is within the reference flatness range (Yes in step S52 of FIG. 24), that is, when the surface of the sublimable substance solid 121 is sufficiently flat. 24, the measurement of the thickness of the pre-drying treatment liquid film 120 by the film thickness measurement unit 191 is stopped (step S26 in FIG. 24). Thereafter, the sublimation step (step S10 in FIG. 9) is performed as usual. Therefore, it is possible to obtain the substrate W in which the collapse rate of the pattern PA is reduced.

If the flatness measured in the flatness measuring step is not within the reference flatness range (No in step S52 of FIG. 24), that is, if the surface of the sublimable solid 121 is not sufficiently flat, the substrate W solid 121 of the sublimable substance is removed from the upper surface of (solid removal step, step S53 in FIG. 24). In the solid removal step, as shown in FIG. 25B, a solvent corresponding to the replacement liquid is supplied from the replacement liquid nozzle 43 onto the upper surface of the substrate W on which the sublimable solid 121 is formed.

FIG. 25B shows an example in which the dry pretreatment liquid is a solution of camphor and IPA and the solvent is IPA. When the drying pretreatment liquid is a solution of camphor and methanol, methanol is discharged from the substitution liquid nozzle 43 instead of IPA. As a result, as shown in FIG. 25C, the sublimable solid 121 is removed. After that, the measurement of the thickness of the pre-drying treatment liquid film 120 by the film thickness measurement unit 191 is stopped (step S26 in FIG. 24).

In the film thickness monitoring process of the fifth example, since the solid removal process is executed, even when a part of the solid 121 of the sublimation substance is too thin or too thick, collapse of the pattern PA is suppressed. can do. Further, since the sublimable substance solid 121 on the upper surface of the substrate W is removed, the substrate W can be reused.
Thus, when the dry pretreatment liquid is a solution of camphor and IPA, IPA serves as a solids removing liquid to remove sublimable solids 121 from the upper surface of the substrate W in the solids removing step. When the dry pretreatment liquid is a solution of camphor and methanol, methanol serves as the solid removal liquid in the solid removal step. The solid removal liquid is preferably the same type of liquid as the solvent used in the pre-drying treatment liquid, but is not limited to this. The solid removal liquid may be a liquid different from the solvent of the pre-drying treatment liquid as long as the solid 121 of the sublimable substance can be removed.

The substrate processing apparatus 1 is arranged in a clean room, and the temperature in the substrate processing apparatus 1 is maintained at the same or substantially the same value as the temperature in the clean room. temperature may be different. For example, the substrate processing apparatus 1 may be provided with an air conditioner for adjusting the temperature inside the substrate processing apparatus 1 .
When the pre-drying treatment liquid is a solution of camphor and methanol, the temperature in the substrate processing apparatus 1, more specifically, the temperature in the chamber 4 is the temperature of the surface of the pre-drying treatment liquid when the sublimable substance is deposited. If it is higher than the temperature (hereinafter referred to as "surface temperature at the time of deposition"), the temperature of the interface between the solid 121 of the sublimation substance and the pre-drying treatment liquid rises simply by leaving the pre-drying treatment liquid on the upper surface of the substrate W. , the sublimable substance solid 121 is dissolved in the drying pretreatment liquid. As a result, deposition and dissolution of the sublimable substance are naturally repeated.

When the temperature in the clean room is lower than the surface temperature during deposition, the controller 3 causes the air conditioner to increase the temperature inside the substrate processing apparatus 1 so that the inner space of the chamber 4 is maintained at a temperature higher than the surface temperature during deposition. You may adjust. Similarly, when the air pressure in the clean room is a value unsuitable for deposition and dissolution of the sublimable substance, the controller 3 determines that at least the output of the FFU 6 (see FIG. 2) and the opening of the exhaust valve 9 (see FIG. 2) You can change one. In this case, at least one of the flow rate of the gas supplied into the chamber 4 and the flow rate of the gas discharged from the chamber 4 is changed, and the pressure inside the chamber 4 is adjusted to a level suitable for deposition and dissolution of the sublimable substance. value is maintained.

The substrate processing apparatus 1 may include at least one of a thermometer that measures the temperature inside the chamber 4 and a barometer that measures the pressure inside the chamber 4 . If at least one of the temperature and atmospheric pressure inside the chamber 4 changes significantly while the substrate W is being processed in the processing unit 2, the controller 3 detects that both the temperature and the atmospheric pressure inside the chamber 4 cause precipitation of the sublimable substance and Loading of the next substrate W into the chamber 4 may be stopped until the value suitable for dissolution is maintained.

The substrate processing apparatus 1 is not limited to an apparatus for processing disk-shaped substrates W, and may be an apparatus for processing polygonal substrates W. FIG.
In addition, various design changes can be made within the scope of the matters described in the claims.

Reference Signs List 1: substrate processing apparatus 3: controller 10: spin chuck 14: spin motor (solvent evaporation unit, sublimation unit)
39: pre-drying treatment liquid nozzle (pre-drying treatment liquid supply unit)
55: center nozzle (solvent evaporation unit, sublimation unit)
61: Upper central opening of blocking member (solvent evaporation unit, sublimation unit)
71: bottom nozzle (solvent evaporation unit)
91: film thickness measurement unit 120: pre-drying treatment liquid film (liquid film of pre-drying treatment liquid)
121: solid of sublimation substance 191: film thickness measurement unit PA: pattern W: substrate

Claims (16)

a pre-drying treatment liquid, which is a solution in which a sublimable substance is dissolved in a solvent, is supplied to the upper surface of a substrate having a pattern formed thereon to form a liquid film of the pre-drying treatment liquid on the upper surface of the substrate; a treatment liquid supply step;
a deposition step of depositing a solid of the sublimable substance on the upper surface of the substrate by evaporating the solvent from the liquid film;
In the precipitation step, the sublimable substance in the liquid film is determined based on the film thickness reduction rate, which is the speed at which the thickness of the liquid film decreases due to the evaporation of the solvent, before the solid of the sublimable substance precipitates. a concentration determination step of determining whether the concentration of is within the reference concentration range;
a sublimation step of sublimating a solid of the sublimation substance after the deposition step is completed when the concentration of the sublimation substance in the liquid film is determined to be within a reference concentration range in the concentration determination step; A method of processing a substrate, comprising: wherein the concentration determining step estimates the concentration of the sublimable substance in the liquid film by comparing preliminarily measured reference data with the film thickness reduction rate measured during the deposition step; 2. The substrate processing method of claim 1, comprising: When it is determined in the concentration determination step that the concentration of the sublimation substance in the liquid film is not within the reference concentration range, the removal liquid is applied to the substrate before the solid of the sublimation substance precipitates in the deposition step. 3. The substrate processing method according to claim 1, further comprising a step of removing said pre-drying treatment liquid from said upper surface of said substrate by supplying said pre-drying treatment liquid to said upper surface of said substrate. Evaporation of the solvent from the liquid film during the deposition step when it is determined in the concentration determination step that the concentration of the sublimable substance in the liquid film is lower than the lower limit of the reference concentration range. 3. The substrate processing method according to claim 1, further comprising a solvent evaporation promoting step for promoting the 5. The substrate processing according to claim 4, wherein the solvent evaporation promoting step includes the step of removing vapor of the solvent from an atmosphere in contact with the liquid film by supplying an inert gas toward the atmosphere in contact with the liquid film. Method. a substrate rotation step of rotating the substrate around a rotation axis along a vertical direction in the deposition step;
When it is determined in the concentration determining step that the concentration of the sublimable substance in the liquid film is higher than the upper limit value of the reference concentration range, a solid of the sublimable substance precipitates during the execution of the precipitation step. 6. The substrate processing method according to claim 1, further comprising a thinning step of thinning the liquid film by increasing the rotation speed of the substrate. Evaporation of the solvent from the liquid film during the deposition step when it is determined in the concentration determining step that the concentration of the sublimable substance in the liquid film is higher than the upper limit value of the reference concentration range. The substrate processing method according to any one of claims 1 to 6, further comprising a solvent evaporation suppression step for suppressing the 8. The substrate processing according to claim 7, wherein said solvent evaporation suppressing step includes a step of suppressing evaporation of said solvent from said liquid film by supplying vapor or mist of said solvent to an atmosphere in contact with said liquid film. Method. 9. The method according to any one of claims 1 to 8, further comprising a first abnormality notification step of notifying an abnormality when it is determined in the concentration determination step that the concentration of the sublimable substance in the liquid film is not within the reference concentration range. 1. The substrate processing method according to claim 1. In the deposition step, a film thickness measurement step of measuring the thickness of the liquid film immediately before the solid of the sublimable substance is deposited by evaporation of the solvent;
10. The method according to any one of claims 1 to 9, further comprising a thickness determination step of determining whether the thickness of the liquid film measured in the film thickness measurement step is within a reference thickness range of the solid of the sublimable substance. 1. The substrate processing method according to item 1. 11. The method according to claim 10, further comprising a second abnormality notification step of notifying an abnormality when the thickness of the liquid film measured in the film thickness measurement step is determined not to be within the reference thickness range in the thickness determination step. The substrate processing method described. a first deposition step of depositing a solid of the sublimable substance in the pre-drying treatment liquid on the upper surface of the substrate by evaporating the solvent from the pre-drying treatment liquid on the upper surface of the substrate;
a first dissolving step of dissolving at least part of the solid of the sublimable substance deposited in the first depositing step in the pre-drying treatment liquid on the upper surface of the substrate;
a final deposition step of depositing the solid of the sublimable substance on the upper surface of the substrate by evaporating the solvent from the pre-drying treatment liquid in which the solid of the sublimable substance is dissolved in the first dissolving step; further includes
The precipitation step is the first precipitation step,
the sublimation step is performed after the final precipitation step is completed;
12. The substrate processing method according to claim 10, wherein said first dissolving step is performed when said thickness determining step determines that the thickness of said liquid film is within a reference thickness range. a first deposition step of depositing a solid of the sublimable substance in the pre-drying treatment liquid on the upper surface of the substrate by evaporating the solvent from the pre-drying treatment liquid on the upper surface of the substrate;
a first dissolving step of dissolving at least part of the solid of the sublimable substance in the pre-drying treatment liquid on the upper surface of the substrate in the first deposition step;
a final deposition step of depositing the solid of the sublimable substance on the upper surface of the substrate by evaporating the solvent from the pre-drying treatment liquid in which the solid of the sublimable substance is dissolved in the first dissolving step; further includes
the precipitation step includes at least one of the first precipitation step and the final precipitation step;
A substrate processing method according to any one of the preceding claims, wherein said sublimation step is performed after said final deposition step. a pre-drying treatment liquid, which is a solution in which a sublimable substance is dissolved in a solvent, is supplied to the upper surface of a substrate having a pattern formed thereon to form a liquid film of the pre-drying treatment liquid on the upper surface of the substrate; a treatment liquid supply step;
a deposition step of depositing a solid of the sublimable substance on the upper surface of the substrate by evaporating the solvent from the liquid film;
In the deposition step, after the solid of the sublimable substance is deposited by evaporation of the solvent, the sublimation is performed by measuring the height position of the surface of the solid of the sublimable substance at a plurality of locations on the upper surface of the substrate. a flatness measuring step of measuring the flatness of the solid surface of the material;
a flatness determination step of determining whether the flatness measured in the flatness measurement step is within a reference flatness range;
and a sublimation step of sublimating a solid of the sublimable substance when the flatness determination step determines that the degree of flatness is within the reference flatness range. When it is determined in the flatness measuring step that the flatness is not within the reference flatness range, a removal liquid is supplied to the upper surface of the substrate to remove the sublimable substance solid from the upper surface of the substrate. 15. The substrate processing method of claim 14, further comprising a solids removal step. a pre-drying treatment liquid supply unit for supplying a pre-drying treatment liquid, which is a solution in which a sublimable substance is dissolved in a solvent, to the upper surface of the patterned substrate so as to form a liquid film on the upper surface of the substrate; ,
a solvent evaporation unit for evaporating the solvent from the liquid film so that the solid of the sublimable substance is deposited;
a film thickness measuring unit for measuring the thickness of the liquid film;
a sublimation unit for sublimating a solid of the sublimable substance formed on the substrate;
and a controller for determining whether the concentration of the sublimable substance in the liquid film is within a reference concentration range.

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