Substrate processing method

Abstract

A substrate processing method includes: a drying pre-processing liquid supply step of supplying a drying pre-processing liquid in which a sublimable substance is dissolved in a solvent to an upper surface of a substrate on which a pattern is formed, and forming a liquid film of the drying pre-processing liquid on the upper surface of the substrate; a precipitation step in which a solid of the sublimable substance is precipitated on the upper surface of the substrate by evaporating the solvent from the liquid film; and a flatness measurement step for 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 after the solid of the sublimable substance is precipitated by the evaporation of the solvent in the precipitation step, thereby measuring the flatness of the solid of the sublimable substance. Measuring the flatness of the surface of the solid of the sublimable substance; a flatness determination step for determining whether or not the flatness measured in the flatness measurement step is within a reference flatness range; and a sublimation step for sublimating the solid of the sublimable substance when it is determined in the flatness determination step that the degree of flatness is within the reference flatness range.

Description

[0001] This application is a divisional application of a Chinese patent application with the original application having a filing date of November 25, 2019, an application number of 201980086789.8, and an invention title of "Substrate Processing Method and Substrate Processing Apparatus". Technical Field

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

[0003] In the manufacturing processes of semiconductor devices, FPDs, etc., substrates such as semiconductor wafers and glass substrates for FPDs are processed as needed. Such processing includes supplying processing liquids such as chemical liquids and rinsing liquids to the substrate. After supplying the processing liquid, the processing liquid is removed from the substrate, and the substrate is dried. In a single-substrate processing apparatus that processes substrates one by one, spin drying is performed, that is, the substrate is dried by removing the liquid on the substrate by using the high-speed rotation of the substrate.

[0004] When a pattern is formed on the surface of the substrate, when the substrate is dried, sometimes a force generated by the surface tension of the processing liquid attached to the substrate is applied to the pattern, causing the pattern to collapse. As a countermeasure, the following methods are adopted: supplying a liquid with a low surface tension such as IPA (isopropyl alcohol) to the substrate, or supplying a hydrophobizing agent that makes the contact angle of the liquid with respect to the pattern close to 90 degrees to the substrate. However, even when using IPA or a hydrophobizing agent, the collapsing force that causes the pattern to collapse is not zero. Therefore, depending on the strength of the pattern, there are cases where even with these countermeasures, the collapse of the pattern cannot be sufficiently prevented.

[0005] In recent years, as a technique for preventing the collapse of patterns, sublimation drying has attracted attention. For example, a substrate processing method and a substrate processing apparatus for performing sublimation drying are disclosed in Patent Document 1. In the sublimation drying described in Patent Document 1, a solution of a sublimable substance is supplied to the upper surface of the substrate, and the DIW (deionized water) on the substrate is replaced with the solution of the sublimable substance. Thereafter, the solvent of the sublimable substance is evaporated, and the sublimable substance is precipitated. Accordingly, a film containing the solid sublimable substance is formed on the upper surface of the substrate. Thereafter, the substrate is heated. Accordingly, the sublimable substance on the substrate sublimes and is removed from the substrate.

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Patent Laid-Open Publication No. 2012-243869 Summary of the Invention

[0009] Problems to be Solved by the Invention

[0010] Generally, compared with conventional drying methods such as freeze drying and spin drying that uses high-speed rotation of a substrate to remove liquid, and IPA drying that uses IPA, the pattern collapse rate is lower in freeze drying. However, if the strength of the pattern is extremely low, there is a case where even if freeze drying is performed, it is impossible to sufficiently prevent the pattern from collapsing. According to the research by the inventors of the present application, one of the reasons is the thickness of the film of the sublimable substance containing a solid.

[0011] The thickness of the solid of the sublimable substance corresponds to the thickness of the solution of the sublimable substance when the saturated concentration of the sublimable substance is reached. As long as the concentration of the sublimable substance in the solution of the sublimable substance can be known before the saturated concentration of the sublimable substance is reached, the thickness of the solid of the sublimable substance can be predicted, and the formation of a solid of the sublimable substance with an inappropriate thickness can be avoided.

[0012] Generally, in order to measure the concentration of a substance in a liquid, it is necessary to bring an instrument for concentration measurement into contact with the liquid. Since the solution of the sublimable substance formed on the substrate is thin, it is difficult to bring the instrument for concentration measurement into contact with the liquid film without contacting the upper surface of the substrate. Therefore, there is a risk of pattern damage and collapse due to contact with the instrument for concentration measurement.

[0013] Therefore, one object of the present invention is to provide a substrate processing method and a substrate processing apparatus that can reduce the pattern collapse rate that occurs when removing a sublimable substance from the upper surface of a substrate by sublimation.

[0014] Technical Means for Solving the Problems

[0015] One embodiment of the present invention provides a substrate processing method, comprising: a pre-drying treatment liquid supply step of supplying a solution obtained by dissolving a sublimable substance in a solvent, i.e., a pre-drying treatment liquid, onto the upper surface of a substrate having a pattern formed thereon, and forming a liquid film of the pre-drying treatment liquid on the upper surface of the substrate; a precipitation step of evaporating the solvent from the liquid film to precipitate a solid of the sublimable substance on the upper surface of the substrate; a concentration determination step of determining whether the concentration of the sublimable substance in the liquid film is within a reference concentration range based on the rate of decrease in the thickness of the liquid film, i.e., the film thickness reduction rate, due to the evaporation of the solvent before the solid of the sublimable substance is precipitated in the precipitation step; and a sublimation step of sublimating the solid of the sublimable substance after the precipitation step when it is determined in the concentration determination step that the concentration of the sublimable substance in the liquid film is within the reference concentration range.

[0016] According to this method, a solution obtained by dissolving a sublimable substance in a solvent is supplied onto the upper surface of a substrate. Thereby, a liquid film of the pre-drying treatment liquid is formed on the upper surface of the substrate. Thereafter, 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, a solid of the sublimable substance precipitates in the liquid film of the pre-drying treatment liquid.

[0017] 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 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, it is possible to determine whether the concentration of the sublimable substance in the liquid film is within the reference concentration range before the solid of the sublimable substance is precipitated, i.e., before the concentration of the sublimable substance reaches the saturation concentration of the sublimable substance. When it is determined that the concentration of the sublimable substance in the liquid film is within the reference concentration range, a solid of the sublimable substance having an appropriate thickness is formed. And since the solid of the sublimable substance is sublimated after the precipitation step, a substrate with a reduced pattern collapse rate can be obtained.

[0018] On the other hand, when it is determined that the concentration of the sublimable substance in the liquid film is not within the reference concentration range, if the substrate processing is interrupted, it is possible to prevent the situation where a solid of the sublimable substance having an inappropriate thickness is sublimated. Accordingly, an increase in the pattern collapse rate can be suppressed.

[0019] In one embodiment of the present invention, the above-mentioned concentration determination step includes the following steps: by comparing the previously measured reference data with the film thickness reduction rate measured in the above-mentioned precipitation step, the concentration of the sublimable substance in the above-mentioned liquid film is estimated. Therefore, in the precipitation step, the concentration of the sublimable substance in the liquid film can be easily estimated.

[0020] In one embodiment of the present invention, the above-mentioned substrate treatment method further includes a pre-drying treatment liquid removal step. When it is determined in the above-mentioned concentration determination step that the concentration of the sublimable substance in the above-mentioned liquid film is not within the above-mentioned reference concentration range, the pre-drying treatment liquid removal step supplies a removal liquid to the upper surface of the above-mentioned substrate before the solid precipitation of the sublimable substance in the above-mentioned precipitation step, so as to remove the pre-drying treatment liquid from the upper surface of the above-mentioned substrate.

[0021] According to this method, when the concentration of the sublimable substance in the liquid film is not within the reference concentration range, before the solid precipitation of the sublimable substance, the sublimable substance can be removed from the upper surface of the substrate by the removal liquid. Accordingly, it is possible to prevent the formation of a solid of the sublimable substance with an inappropriate thickness on the upper surface of the substrate. Accordingly, an increase in the pattern collapse rate can be suppressed. In addition, since the pre-drying treatment liquid on the upper surface of the substrate is removed, the substrate can be reused.

[0022] In one embodiment of the present invention, the above-mentioned substrate treatment method further includes a solvent evaporation promotion step. When it is determined in the above-mentioned concentration determination step that the concentration of the sublimable substance in the above-mentioned liquid film is lower than the lower limit value of the above-mentioned reference concentration range, the solvent evaporation promotion step promotes the evaporation of the solvent from the above-mentioned liquid film during the execution of the above-mentioned precipitation step.

[0023] According to this method, when 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 lower than the lower limit value of the reference concentration range, the evaporation of the solvent from the liquid film of the pre-drying treatment liquid is promoted. If the evaporation of the solvent from the liquid film of the pre-drying treatment liquid is promoted, 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 to be 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 lower than the lower limit value of the reference concentration range, a substrate with a reduced pattern collapse rate can be obtained.

[0024] In one embodiment of the present invention, the above-mentioned solvent evaporation promotion step includes the following steps: by supplying an inert gas to the gas atmosphere in contact with the above-mentioned liquid film, the vapor of the solvent is removed from the gas atmosphere in contact with the above-mentioned liquid film.

[0025] According to this method, an inert gas is supplied, and the vapor of the solvent is removed from the gas atmosphere in contact with the liquid film of the pre-drying treatment liquid on the upper surface of the substrate. Therefore, the evaporation of the solvent from the liquid film of the pre-drying treatment liquid can be promoted.

[0026] In one embodiment of the present invention, the above substrate processing method further includes: a substrate rotation step of rotating the upper surface of the substrate around a rotation axis along the vertical direction in the above precipitation step; and a thinning step of thinning the liquid film by increasing the rotation speed of the substrate before the solid precipitation of the sublimable substance during the execution of the above precipitation step when it is determined in the above concentration determination step that the concentration of the sublimable substance in the liquid film is higher than the upper limit value of the above reference concentration range.

[0027] When 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, that is, the thickness of the solid of the sublimable substance before sublimation is greater than the intended value. If 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, and therefore, the thickness of the solid of the sublimable substance is also reduced.

[0028] Therefore, when 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, by increasing the rotation speed of the substrate, centrifugal force acts on the liquid film of the pre-drying treatment liquid on the upper surface of the substrate, so that the thickness of the liquid film of the pre-drying treatment liquid can be reduced before the solid precipitation of the sublimable substance. Accordingly, the solid of the sublimable substance with the intended thickness can be precipitated. 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 value of the reference concentration range, a substrate with a reduced pattern collapse rate can be obtained.

[0029] In one embodiment of the present invention, the above substrate processing method further includes a solvent evaporation suppression step, and the solvent evaporation suppression step is to suppress the evaporation of the solvent from the liquid film during the execution of the above precipitation step when it is determined in the above concentration determination step that the concentration of the sublimable substance in the liquid film is higher than the upper limit value of the above reference concentration range.

[0030] 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 value of the reference concentration range, the evaporation of the solvent from the liquid film of the pre-drying treatment liquid is suppressed. If the evaporation of the solvent from the liquid film of the pre-drying treatment liquid is suppressed, the ratio of the sublimable substance in the substances evaporated from the liquid film increases. Accordingly, the concentration of the sublimable substance in the liquid film of the pre-drying treatment liquid is reduced. 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.

[0031] 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 value of the reference concentration range, a substrate with a reduced pattern collapse rate can be obtained.

[0032] In one embodiment of the present invention, the solvent evaporation inhibition step includes the following step: by supplying the vapor or mist of the solvent to the gas atmosphere in contact with the liquid film, the evaporation of the solvent from the liquid film is inhibited.

[0033] According to this method, by supplying the vapor or mist of the solvent to the gas 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 gas atmosphere in contact with the liquid film of the pre-drying treatment liquid increases. Therefore, the evaporation of the solvent from the liquid film of the pre-drying treatment liquid is inhibited.

[0034] In one embodiment of the present invention, the substrate processing method further includes a first abnormality notification step, and the first abnormality notification step is to notify 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. Therefore, based on the notification of the abnormality, it is possible to judge whether to continue the substrate processing at an appropriate timing.

[0035] In one embodiment of the present invention, the substrate processing method further includes: a film thickness measurement step, which measures the thickness of the liquid film before the solid of the sublimable substance is about to precipitate due to the evaporation of the solvent in the precipitation step; and a thickness determination step, which determines whether the thickness of the liquid film measured in the film thickness measurement step is within the reference thickness range of the solid of the sublimable substance.

[0036] According to this method, it is determined whether the thickness of the liquid film before the solid of the sublimable substance is about to precipitate, that is, the thickness of the liquid film 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. Accordingly, it is possible to determine whether the thickness of the solid of the sublimable substance formed on the upper surface of the substrate is appropriate.

[0037] When the thickness of the solid of the sublimable substance formed on the upper surface of the substrate is appropriate, after the precipitation step is completed, a solid of the sublimable substance with an appropriate thickness is formed. Therefore, a substrate with a reduced pattern collapse rate can be obtained.

[0038] On the other hand, when the thickness of the solid of the sublimable substance formed on the upper surface of the substrate is not appropriate, the increase in the pattern collapse rate can be suppressed by interrupting the substrate processing.

[0039] In one embodiment of the present invention, the above substrate processing method further includes a second abnormality notification step. The second abnormality notification step is to notify an abnormality when it is determined in the thickness determination step that the thickness of the liquid film measured in the film thickness measurement step is not within the above reference thickness range. Therefore, based on the notification of the abnormality, it is possible to judge whether to continue substrate processing at an appropriate timing.

[0040] In one embodiment of the present invention, the above substrate processing method further includes: a first precipitation step, which is to precipitate the solid of the sublimable substance in the pre-drying treatment liquid on the upper surface of the substrate by evaporating the above solvent from the pre-drying treatment liquid on the upper surface of the substrate; a first dissolution step, which is to dissolve at least a part of the solid of the sublimable substance in the first precipitation step in the pre-drying treatment liquid on the upper surface of the substrate; and a final precipitation step, which is to precipitate the solid of the sublimable substance on the upper surface of the substrate by evaporating the above solvent from the pre-drying treatment liquid formed by dissolving the solid of the sublimable substance in the first dissolution step. Further, the above precipitation step is the first precipitation step, and the sublimation step is performed after the final precipitation step ends. In addition, the first dissolution step is performed when it is determined in the thickness determination step that the thickness of the liquid film is within the reference thickness range.

[0041] 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 dissolution step, at least a part of the solid of the sublimable substance is dissolved in the pre-drying treatment liquid. Thereafter, in the final precipitation step, the solvent is evaporated from the pre-drying treatment liquid again. Accordingly, the content of the solvent decreases, and the solid of the sublimable substance precipitates on the upper surface of the substrate.

[0042] Before the solid of the sublimable substance is precipitated for the first time, the pre-drying treatment liquid exists not only between the patterns but also above the patterns. In substrates such as semiconductor wafers and substrates for FPDs, the pitch of the patterns is narrow. When the pitch of the patterns is narrow, the properties of the pre-drying treatment liquid existing between the patterns are different from those of the main body of the pre-drying treatment liquid, that is, the pre-drying treatment liquid 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. The difference in their properties becomes significant as the pitch of the patterns becomes narrower.

[0043] If the interval of the pattern is narrow, the following situation exists: when the solid of the sublimable substance first precipitates, the solid of the sublimable substance only precipitates in the main body of the pre-drying treatment liquid, and the solid of the sublimable substance does not exist or hardly exists in the incomplete precipitation region between the patterns formed in the upper surface of the substrate. In this case, the surface tension of the pre-drying treatment liquid between the patterns acts on the side surfaces of the patterns. Therefore, when the solid of the sublimable substance sublimes, the patterns in the incomplete precipitation region may collapse. This becomes the reason for increasing (deteriorating) the collapse rate of the patterns.

[0044] In contrast, if the solid of the sublimable substance that has precipitated is dissolved in the pre-drying treatment liquid and then the solid of the sublimable substance is precipitated again, crystal nuclei of the solid of the sublimable substance are also formed in narrow spaces such as the space between the patterns. Therefore, as long as the solid of the sublimable substance that has precipitated is dissolved in the pre-drying treatment liquid in the first dissolution step and then the solid of the sublimable substance is precipitated again in the final precipitation step, even when the interval of the patterns is narrow, the generation of the incomplete precipitation region can be prevented or its area can be reduced.

[0045] In addition, according to this method, the first dissolution step starts when it is determined in the thickness determination step that the thickness of the liquid film of the pre-drying treatment liquid is within the reference thickness range. In other words, the first dissolution step starts with the solid of the sublimable substance having an appropriate thickness formed. Therefore, only when the solid of the sublimable substance having an appropriate thickness is formed, the first dissolution step, the final precipitation step, and the sublimation step are executed. After the sublimation step, a substrate with a reduced pattern collapse rate can be obtained.

[0046] When the solid of the sublimable substance having an appropriate thickness is not formed, the steps after the first precipitation step (the first dissolution step, the final precipitation step, and the sublimation step) may not be executed, and the substrate treatment can be interrupted early.

[0047] In one embodiment of the present invention, the above substrate treatment method further includes: a first precipitation step, which is to precipitate the 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 dissolution step, which is to dissolve at least a part of the solid of the sublimable substance in the pre-drying treatment liquid on the upper surface of the substrate; and a final precipitation step, which is to precipitate 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. Further, the precipitation step includes at least one of the first precipitation step and the final precipitation step, and the sublimation step is executed after the final precipitation step.

[0048] According to this method, after the solid of the sublimable substance that has precipitated is dissolved in the pretreatment liquid before drying, the solid of the sublimable substance precipitates again. Therefore, even when the interval of the pattern is narrow, the generation of an incomplete precipitation region can be prevented or its area can be reduced. Accordingly, the collapse of the pattern can be reduced and the pattern collapse rate can be lowered.

[0049] In addition, according to this method, in at least any 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, it is determined whether the concentration of the sublimable substance in the liquid film is within the reference concentration range. When it is determined that the concentration of the sublimable substance in the liquid film is within the reference concentration range, a solid of the sublimable substance with an appropriate thickness is formed. And since the solid of the sublimable substance is sublimated after the final precipitation step is completed, a substrate with a reduced pattern collapse rate can be obtained.

[0050] On the other hand, when it is determined that the concentration of the sublimable substance in the liquid film is not within the reference concentration range, if the substrate treatment is interrupted, the situation where the solid of the sublimable substance with an inappropriate thickness is sublimated can be prevented. Accordingly, an increase in the pattern collapse rate can be suppressed.

[0051] The pattern collapse rate depends on the thickness of the solid of the sublimable substance finally formed on the upper surface of the substrate. Therefore, the concentration determination step is preferably performed in the final precipitation step. However, the amount of the solvent evaporated in the first dissolution step and the final precipitation step can be predicted. Therefore, even when the concentration determination step is performed in the first precipitation step, it is possible to determine whether the thickness of the solid of the sublimable substance formed on the upper surface of the substrate is appropriate based on the concentration of the sublimable substance in the liquid film in the first precipitation step.

[0052] Another embodiment of the present invention provides a substrate processing method, which includes: a pre-drying treatment liquid supply step of supplying a solution obtained by dissolving a sublimable substance in a solvent, i.e., a pre-drying treatment liquid, to the upper surface of a patterned substrate to form a liquid film of the pre-drying treatment liquid on the upper surface of the substrate; a precipitation step of evaporating the solvent from the liquid film to precipitate a solid of the sublimable substance on the upper surface of the substrate; a flatness measurement step of measuring the flatness of the surface of the solid of the sublimable substance by measuring the height positions of the solid of the sublimable substance at multiple positions on the upper surface of the substrate after the solid of the sublimable substance is precipitated by evaporation of the solvent in the precipitation step; 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 the solid of the sublimable substance when it is determined in the flatness determination step that the flatness is within the reference flatness range.

[0053] According to this method, a solution obtained by dissolving a sublimable substance in a solvent is supplied to the upper surface of the substrate. Accordingly, a liquid film of the pre-drying treatment liquid is formed on the upper surface of the substrate. Thereafter, 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, a solid of the sublimable substance precipitates in the liquid film of the pre-drying treatment liquid.

[0054] When there is a portion with an overly thin or overly thick thickness in a part of the solid of the sublimable substance, there is a risk of an increase in the pattern collapse rate in this portion. Therefore, the flatness of the surface of the solid of the sublimable substance precipitated on the upper surface of the substrate is measured, and it is determined whether the measured flatness is within a reference flatness range. Accordingly, it is possible to check whether a solid of the sublimable substance with a uniform thickness is formed in all regions of the upper surface of the substrate.

[0055] When it is determined that the flatness of the solid of the sublimable substance is within the reference flatness range, the solid of the sublimable substance is sublimated. Therefore, a substrate with a reduced pattern collapse rate can be obtained. On the other hand, when it is determined that the flatness of the solid of the sublimable substance is not within the reference flatness range, it is possible to suppress the production of a substrate with an increased pattern collapse rate by interrupting the substrate processing.

[0056] In another embodiment of the present invention, the substrate processing method further includes a solid removal step of removing the solid of the sublimable substance from the upper surface of the substrate by supplying a removal liquid to the upper surface of the substrate when it is determined in the flatness measurement step that the flatness is not within the reference flatness range.

[0057] According to this method, when the 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, when there are parts with too thin or too thick thickness in a part of the solid of the sublimable substance, it is also possible to suppress the collapse of the pattern. In addition, since the solid of the sublimable substance on the upper surface of the substrate is removed, the substrate can be reused.

[0058] Another embodiment of the present invention provides a substrate processing apparatus, which includes: a pre-drying treatment liquid supply unit that supplies a solution obtained by dissolving a sublimable substance in a solvent, that is, a pre-drying treatment liquid, to the upper surface of the substrate so as to form a liquid film on the upper surface of the substrate on which a pattern is formed; a solvent evaporation unit that evaporates the solvent from the liquid film so that the solid of the sublimable substance precipitates; a film thickness measurement unit that measures the thickness of the liquid film; a sublimation unit that sublimates the solid of the sublimable substance formed on the substrate; and a controller that determines whether the concentration of the sublimable substance in the liquid film is within the reference concentration range. According to this configuration, the same effects as the above-described substrate processing method are achieved.

[0059] With reference to the accompanying drawings and through the description of the embodiments described below, the above object, or further other objects, features, and effects in the present invention will become clear. Description of the Drawings

[0060] Figure 1A is a schematic view of a substrate processing apparatus according to an embodiment of the present invention as viewed from above.

[0061] Figure 1B is a schematic view of the above substrate processing apparatus as viewed from the side.

[0062] Figure 2 is a schematic view of the inside of a processing unit included in the above substrate processing apparatus as viewed horizontally.

[0063] Figure 3 is a schematic view of a film thickness measurement unit, a rotating chuck, and a blocking member included in the above processing unit as viewed horizontally.

[0064] Figure 4 is a schematic view of the above film thickness measurement unit and the above rotating chuck as viewed from above.

[0065] Figure 5 is a cross-sectional view of the inside of a housing that houses a light-emitting element included in the above film thickness measurement unit.

[0066] Figure 6 is along Figure 5 the cross-sectional view taken along the line VI-VI shown.

[0067] Figure 7 It is a schematic diagram showing the pre-drying treatment liquid supply device provided in the above-mentioned substrate processing apparatus.

[0068] Figure 8 It is a block diagram showing the hardware of the controller provided in the above-mentioned substrate processing apparatus.

[0069] Fig. 9 It is a flowchart for explaining an example of substrate processing performed using the above-mentioned substrate processing apparatus.

[0070] Fig. 10A It is a schematic diagram showing the state of the substrate when using a solution of camphor and IPA.

[0071] Fig. 10B It is a schematic diagram showing the state of the substrate when using a solution of camphor and IPA.

[0072] Fig. 10C It is a schematic diagram showing the state of the substrate when using a solution of camphor and IPA.

[0073] Fig. 10D It is a schematic diagram showing the state of the substrate when using a solution of camphor and IPA.

[0074] Fig.10E It is a schematic diagram showing the state of the substrate when using a solution of camphor and IPA.

[0075] Fig.10F It is a schematic diagram showing the state of the substrate when using a solution of camphor and IPA.

[0076] Fig.11 It is an equilibrium state diagram of camphor and IPA.

[0077] Fig. 12A It is a schematic diagram showing the state of the substrate when using a solution of camphor and methanol.

[0078] Fig. 12B It is a schematic diagram showing the state of the substrate when using a solution of camphor and methanol.

[0079] Fig. 12C It is a schematic diagram showing the state of the substrate when using a solution of camphor and methanol.

[0080] Fig.12D It is a schematic diagram showing the state of the substrate when using a solution of camphor and methanol.

[0081] Fig.13 It is a graph showing the pattern overturning rate.

[0082] Fig.14It is a graph showing the change in the thickness of the liquid film of the pre-drying treatment liquid on the upper surface of the substrate over time until the solid of the sublimable substance precipitates from the pre-drying treatment liquid.

[0083] Fig.15 It is a flowchart showing the first example of the film thickness monitoring process.

[0084] Fig.16 It is a schematic diagram for explaining the abnormal treatment process in the first example of the film thickness monitoring process.

[0085] Fig.17 It is a flowchart showing the second example of the film thickness monitoring process.

[0086] Fig.18 It is a schematic diagram for explaining the solvent evaporation inhibition process in the second example of the film thickness monitoring process.

[0087] Fig.19 It is a schematic diagram for explaining the solvent evaporation promotion process in the second example of the film thickness monitoring process.

[0088] Fig. 20 It is a flowchart showing the third example of the film thickness monitoring process.

[0089] Fig.21A It is a schematic diagram for explaining the film formation process in the third example of the film thickness monitoring process.

[0090] Fig. 21B It is a schematic diagram for explaining the film formation process in the third example of the film thickness monitoring process.

[0091] Fig. 22 It is a flowchart showing the fourth example of the film thickness monitoring process.

[0092] Fig.23 It is a flowchart for explaining another example of the substrate treatment performed using the above substrate treatment device.

[0093] Fig.24 It is a flowchart showing the fifth example of the film thickness monitoring process.

[0094] Fig.25A It is a schematic diagram for explaining the flatness measurement process in the above substrate treatment.

[0095] Fig.25B It is a schematic diagram for explaining the solid removal process in the above substrate treatment.

[0096] Fig.25C It is a schematic diagram for explaining the solid removal process in the above substrate treatment. Detailed implementation mode

[0097] In the following description, unless otherwise specified, the air pressure inside the substrate processing apparatus 1 is maintained at the air pressure in the clean room where the substrate processing apparatus 1 is installed (for example, 1 atmospheric pressure or a value near it).

[0098] Figure 1A It is a schematic view of a substrate processing apparatus 1 according to an embodiment of the present invention as viewed from above. Figure 1B It is a schematic view of the substrate processing apparatus 1 as viewed from the side.

[0099] As Figure 1A As shown, the substrate processing apparatus 1 is a single-wafer type apparatus that processes circular plates such as semiconductor wafers W one by one. The substrate processing apparatus 1 includes: a load port LP that holds a carrier CA accommodating the substrate W; a plurality of processing units 2 that process the substrate W carried from the carrier CA on the load port LP using a processing fluid such as a processing liquid or a processing gas; a transfer robot that transfers the substrate W between the carrier CA on the load port LP and the processing units 2; and a controller 3 that controls the substrate processing apparatus 1.

[0100] The transfer robot includes: an indexing robot IR that loads and unloads the substrate W to and from the carrier CA on the load port LP; and a central robot CR that loads and unloads the substrate W to and from the plurality of processing units 2. The indexing robot IR transfers the substrate W between the load port LP and the central robot CR, and the central robot CR transfers the substrate W between the indexing robot IR and the processing units 2. The central robot CR includes a hand H1 that supports the substrate W, and the indexing robot IR includes a hand H2 that supports the substrate W.

[0101] The plurality of processing units 2 form a plurality of towers TW arranged around the central robot CR in a plan view. Figure 1A An example in which 4 towers TW are formed is shown. The central robot CR can enter any of the towers TW. As Figure 1B As shown, each tower TW includes a plurality of (for example, 3) processing units 2 stacked vertically.

[0102] Figure 2 It is a schematic view of the inside of the processing unit 2 included in the substrate processing apparatus 1 as viewed horizontally.

[0103] The processing unit 2 is a wet processing unit 2w that supplies a processing liquid to the substrate W. The processing unit 2 includes: a box-shaped chamber 4 having an internal space; a rotary chuck 10 that horizontally holds one substrate W inside the chamber 4 and rotates it around a vertical rotation axis A1 passing through the central portion of the upper surface of the substrate W; and a cylindrical processing cup 21 that surrounds the rotary chuck 10 around the rotation axis A1.

[0104] 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 that opens and closes the loading / unloading port 5b. An FFU (fan filter unit) 6 is disposed above an air supply port 5a provided in the upper part of the partition wall 5. The FFU 6 always supplies clean air (air filtered through a filter) from the air supply port 5a into the chamber 4. The gas in the chamber 4 is discharged from the chamber 4 through an exhaust duct 8 connected to the bottom of the processing susceptor 21. Accordingly, a downward flow of clean air is always formed in the chamber 4. The flow rate of the exhaust gas discharged through the exhaust duct 8 is changed according to the opening degree of an exhaust valve 9 disposed in the exhaust duct 8.

[0105] The rotating chuck 10 includes: a disk-shaped rotating base 12 held in a horizontal posture; a plurality of chuck pins 11 that hold the substrate W in a horizontal posture above the rotating base 12; a rotating shaft 13 extending downward from the central part of the rotating base 12; and a rotating motor 14 that rotates the rotating base 12 and the plurality of chuck pins 11 by rotating the rotating shaft 13. The rotating chuck 10 is not limited to a clamping chuck that brings the plurality of chuck pins 11 into contact with the outer peripheral surface of the substrate W, and may also be a vacuum chuck that horizontally holds the substrate W by adsorbing the non-device formation surface, i.e., the back surface (lower surface) of the substrate W, to the upper surface 12u of the rotating base 12.

[0106] The processing susceptor 21 includes: a plurality of sheaths 24 that receive the processing liquid discharged outward from the substrate W; a plurality of susceptors 23 that receive the processing liquid guided downward through the plurality of sheaths 24; and a cylindrical outer wall member 22 that surrounds the plurality of sheaths 24 and the plurality of susceptors 23. Figure 2 An example is shown in which there are 4 sheaths 24 and 3 susceptors 23, and the outermost susceptor 23 is integrated with the third sheath 24 from the top.

[0107] The sheath 24 includes: a cylindrical portion 25 that surrounds the rotating chuck 10; and an annular top portion 26 that extends obliquely upward with respect to the rotation axis A1 from the upper end portion of the cylindrical portion 25. The plurality of top portions 26 overlap vertically, and the plurality of cylindrical portions 25 are arranged concentrically. The annular upper end of the top portion 26 corresponds to the upper end 24u of the sheath 24 that surrounds the substrate W and the rotating base 12 in a plan view. The plurality of susceptors 23 are respectively disposed below the plurality of cylindrical portions 25. The susceptor 23 forms an annular liquid receiving groove for receiving the processing liquid guided downward through the sheath 24.

[0108] The processing unit 2 includes a sheath lifting unit 27 that lifts and lowers the plurality of sheaths 24 respectively. The sheath lifting unit 27 positions the sheath 24 at any position from the upper position to the lower position. The sheath lifting unit 27 is also referred to as a sheath lifter. Figure 2A state is shown in which two sheaths 24 are arranged in the upper position and the remaining two sheaths 24 are arranged in the lower position. The upper position is a position where the upper end 24u of the sheath 24 is arranged at a position higher than the holding position of the substrate W held by the rotating chuck 10. The lower position is a position where the upper end 24u of the sheath 24 is arranged at a position lower than the holding position.

[0109] When supplying a processing liquid to the rotating substrate W, at least one sheath 24 is arranged in the upper position. In this state, when supplying the processing liquid to the substrate W, the processing liquid supplied to the substrate W is thrown off to the periphery of the substrate W. The thrown-off processing liquid collides with the inner surface of the sheath 24 horizontally opposed to the substrate W and is guided to the receiving cup 23 corresponding to the sheath 24. Accordingly, the processing liquid discharged from the substrate W is collected in the processing receiving cup 21.

[0110] The processing unit 2 includes a plurality of nozzles that spray a processing liquid onto the substrate W held by the rotating chuck 10. The plurality of nozzles include: a chemical liquid nozzle 31 that sprays a chemical liquid onto the upper surface of the substrate W; a rinsing liquid nozzle 35 that sprays a rinsing liquid onto the upper surface of the substrate W; a pre-drying processing liquid nozzle 39 that sprays a pre-drying processing liquid onto the upper surface of the substrate W; and a replacement liquid nozzle 43 that sprays a replacement liquid onto the upper surface of the substrate W.

[0111] The chemical liquid nozzle 31 can be a scanning nozzle capable of horizontally moving in the chamber 4 or a fixed nozzle fixed to the partition wall 5 of the chamber 4. The same applies to the rinsing liquid nozzle 35, the pre-drying processing liquid nozzle 39, and the replacement liquid nozzle 43. Figure 2 An example is shown in which the chemical liquid nozzle 31, the rinsing liquid nozzle 35, the pre-drying processing liquid nozzle 39, and the replacement liquid nozzle 43 are scanning nozzles and four nozzle moving units corresponding to the four nozzles are provided.

[0112] The chemical liquid nozzle 31 is connected to a chemical liquid pipe 32 that guides the chemical liquid to the chemical liquid nozzle 31. When the chemical liquid valve 33 installed in the chemical liquid pipe 32 is opened, the chemical liquid is continuously sprayed downward from the spray outlet of the chemical liquid nozzle 31. The chemical liquid sprayed from the chemical liquid nozzle 31 can be a liquid containing at least one of sulfuric acid, nitric acid, hydrochloric acid, hydrofluoric acid, phosphoric acid, acetic acid, ammonia water, hydrogen peroxide water, organic acids (for example, citric acid, oxalic acid, etc.), organic bases (for example, TMAH: tetramethylammonium hydroxide, etc.), surfactants, and preservatives, or can be a liquid other than this.

[0113] Although not shown, the liquid medicine valve 33 includes: a valve body provided with an annular valve seat through which the liquid medicine passes; a valve body capable of moving relative to the valve seat; and a driver that moves the valve body between a closed position where the valve body contacts the valve seat and an open position where the valve body is away from the valve seat. The same applies to other valves. The driver can be a pneumatic driver or an electric driver, or can be a driver other than them. The controller 3 controls the driver to open and close the liquid medicine valve 33.

[0114] The liquid medicine nozzle 31 is connected to a nozzle moving unit 34 that moves the liquid medicine nozzle 31 in at least one of the vertical direction and the horizontal direction. The nozzle moving unit 34 horizontally moves the liquid medicine nozzle 31 between a processing position where the liquid medicine ejected from the liquid medicine nozzle 31 is supplied to the upper surface of the substrate W and a standby position where the liquid medicine nozzle 31 is located around the processing cup 21 in a plan view.

[0115] 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 installed in the rinse liquid pipe 36 is opened, the rinse liquid continuously ejects downward from the ejection port of the rinse liquid nozzle 35. The rinse liquid ejected from the rinse liquid nozzle 35 is, for example, pure water (deionized water: DIW (Deionized Water)). The rinse liquid can also be any one of carbonated water, electrolyzed ion water, hydrogen water, ozone water, and hydrochloric acid water with a dilution concentration (for example, about 10 ppm to 100 ppm).

[0116] 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 horizontally moves the rinse liquid nozzle 35 between a processing position where the rinse liquid ejected 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 located around the processing cup 21 in a plan view.

[0117] 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 installed in the pre-drying treatment liquid pipe 40 is opened, the pre-drying treatment liquid continuously ejects downward from the ejection port of the pre-drying treatment liquid nozzle 39. Similarly, the replacement liquid nozzle 43 is connected to a replacement liquid pipe 44 that guides the replacement liquid to the replacement liquid nozzle 43. When the replacement liquid valve 45 installed in the replacement liquid pipe 44 is opened, the replacement liquid continuously ejects downward from the ejection port of the replacement liquid nozzle 43.

[0118] The pre-drying treatment liquid is a solution containing a sublimable substance as a solute and a solvent that dissolves the sublimable substance. The sublimable substance can be a substance that changes from a solid to a gas without going through a liquid state at normal temperature (synonymous with room temperature) or normal pressure (the pressure inside the substrate processing apparatus 1, for example, 1 atmosphere or a value near it).

[0119] The freezing point of the pre-drying treatment liquid (the freezing point at 1 atmosphere, the same hereinafter) is lower than room temperature (for example, 23°C or a value near it). The substrate processing apparatus 1 is arranged in a clean room maintained at room temperature. Therefore, even without heating the pre-drying treatment liquid, the pre-drying treatment liquid can be maintained as a liquid. The freezing point of the sublimable substance is higher than the freezing point of the pre-drying treatment liquid. The freezing point of the sublimable substance is higher than room temperature. At room temperature, the sublimable substance is a solid. The freezing point of the sublimable substance can also 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.

[0120] The sublimable substance can be, for example, an alcohol such as 2-methyl-2-propanol (alias: tert-Butyl alcohol, t-Butyl alcohol), cyclohexanol; a fluorinated hydrocarbon compound, 1,3,5- trioxane (alias: paraformaldehyde), camphor (alias: camphre, campher), naphthalene, and iodine, or it can be a substance other than them.

[0121] The solvent can be, for example, at least one selected from the group consisting of pure water, IPA, methanol, HFE (hydrofluoroether), acetone, PGMEA (propylene glycol monomethyl ether acetate), PGEE (propylene glycol monoethyl ether, 1-ethoxy-2-propanol), and ethylene glycol.

[0122] Hereinafter, an example in which the sublimable substance is camphor and the solvent is IPA or methanol will be described.

[0123] The freezing point of camphor is 175°C to 177°C. Regardless of whether the solvent is IPA or methanol, the freezing point of camphor is higher than the boiling point of the solvent. The vapor pressure of IPA is higher than the vapor pressure of camphor. Similarly, the vapor pressure of methanol is higher than the vapor pressure of camphor. Therefore, IPA and methanol are more likely to evaporate than camphor. The vapor pressure of IPA is higher than that of water, and the surface tension is lower than that of water. Similarly, the vapor pressure of methanol is higher than that of water, and the surface tension is lower than that of water. The molecular weights of both IPA and methanol are greater than that of water. The molecular weight of methanol is less than that of IPA.

[0124] As described below, the replacement liquid is supplied to the upper surface of the substrate W covered with the liquid film of the rinsing 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 can be any liquid as long as it is compatible with both the rinsing liquid and the pre-drying treatment liquid. The replacement liquid is, for example, IPA (liquid). The replacement liquid can also be a mixture of IPA and HFE, or a liquid other than them. The replacement liquid can be a liquid with the same name as the components of the pre-drying treatment liquid such as a solvent, or a liquid with a name different from any of the components of the pre-drying treatment liquid.

[0125] When the replacement liquid is supplied to the upper surface of the substrate W covered with the liquid film of the rinsing liquid, most of the rinsing liquid on the substrate W is washed away by the replacement liquid and discharged from the substrate W. The remaining trace amount of rinsing liquid dissolves in the replacement liquid and diffuses in the replacement liquid. The diffused rinsing liquid is discharged from the substrate W together with the replacement liquid. Therefore, the rinsing liquid on the substrate W can be effectively replaced with the replacement liquid. For the same reason, the replacement liquid on the substrate W can be effectively replaced with the pre-drying treatment liquid. Accordingly, the rinsing liquid contained in the pre-drying treatment liquid on the substrate W can be reduced.

[0126] 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 horizontally moves the pre-drying treatment liquid nozzle 39 between the processing position where the pre-drying treatment liquid ejected from the pre-drying treatment liquid nozzle 39 is supplied to the upper surface of the substrate W and the standby position where the pre-drying treatment liquid nozzle 39 is located around the processing cup 21 in a plan view.

[0127] 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 the vertical direction and the horizontal direction. The nozzle moving unit 46 horizontally moves the replacement liquid nozzle 43 between the processing position where the replacement liquid ejected from the replacement liquid nozzle 43 is supplied to the upper surface of the substrate W and the standby position where the replacement liquid nozzle 43 is located around the processing cup 21 in a plan view.

[0128] The processing unit 2 includes a blocking member 51 disposed above the rotary chuck 10. Figure 2 An example in which the blocking member 51 is a disc-shaped blocking plate is shown. The blocking member 51 includes a disc portion 52 horizontally disposed above the rotary chuck 10. The blocking member 51 is horizontally supported by a cylindrical support shaft 53 extending upward from the central portion of the disc portion 52. The center line of the disc portion 52 is disposed on the rotation axis A1 of the substrate W. The lower surface of the disc portion 52 corresponds to the lower surface 51L of the blocking member 51. The lower surface 51L of the blocking member 51 is a facing surface opposite to the upper surface of the substrate W. The lower surface 51L of the blocking member 51 is parallel to the upper surface of the substrate W and has an outer diameter larger than the diameter of the substrate W.

[0129] The shut-off member 51 is connected to a shut-off member lifting unit 54 that vertically raises and lowers the shut-off member 51. The shut-off member lifting unit 54 is also referred to as a shut-off member lifter. The shut-off member lifting unit 54 positions the shut-off member 51 at any position from the upper position ( Figure 2 the position shown) to the lower position. The lower position is a proximity position where the lower surface 51L of the shut-off member 51 approaches the upper surface of the substrate W until the height at which a scanning nozzle such as the liquid chemical nozzle 31 cannot enter between the substrate W and the shut-off member 51. The upper position is a separated position where the shut-off member 51 retreats until the height at which the scanning nozzle can enter between the shut-off member 51 and the substrate W.

[0130] The plurality of nozzles includes a center nozzle 55 that ejects a processing fluid such as a processing liquid or a processing gas downward through an upper central opening 61 formed in the central portion of the lower surface 51L of the shut-off member 51. The center nozzle 55 extends vertically along the rotation axis A1. The center nozzle 55 is disposed in a through-hole that vertically penetrates the central portion of the shut-off member 51. The inner peripheral surface of the shut-off member 51 surrounds the outer peripheral surface of the center nozzle 55 with a space therebetween in the radial direction (the direction orthogonal to the rotation axis A1). The center nozzle 55 is lifted and lowered together with the shut-off member 51. The ejection port of the center nozzle 55 that ejects the processing fluid is disposed above the upper central opening 61 of the shut-off member 51.

[0131] The center nozzle 55 is connected to an upper gas pipe 56 that guides an inert gas to the center nozzle 55. The substrate processing apparatus 1 may also include an upper temperature regulator 59 that heats or cools the inert gas ejected from the center nozzle 55. When the upper gas valve 57 installed in the upper gas pipe 56 is opened, the inert gas is continuously ejected downward from the ejection port of the center nozzle 55 at a flow rate corresponding to the opening degree of the flow rate adjustment valve 58 that changes the flow rate of the inert gas. The inert gas ejected from the center nozzle 55 is nitrogen. The inert gas ejected from the center nozzle 55 may also be a gas other than nitrogen such as helium or argon.

[0132] The inner peripheral surface of the blocking member 51 and the outer peripheral surface of the central nozzle 55 form an upper gas flow path 62 in the shape of a cylinder extending vertically. The upper gas flow path 62 is connected to an upper gas pipe 63 that introduces an inert gas into the upper central opening 61 of the blocking member 51. The substrate processing apparatus 1 may also include an upper temperature regulator 66 that heats or cools the inert gas ejected from the upper central opening 61 of the blocking member 51. When the upper gas valve 64 installed in the upper gas pipe 63 is opened, the inert gas is continuously ejected downward from the upper central opening 61 of the blocking member 51 at a flow rate corresponding to the opening degree of the flow rate adjustment valve 65 that changes the flow rate of the inert gas. The inert gas ejected from the upper central opening 61 of the blocking member 51 is nitrogen. The inert gas ejected from the upper central opening 61 of the blocking member 51 may also be a gas other than nitrogen, such as helium or argon.

[0133] The plurality of nozzles include a lower surface nozzle 71 that ejects a processing liquid toward the central portion of the lower surface of the substrate W. The lower surface nozzle 71 includes: a nozzle disk portion that is disposed between the upper surface 12u of the rotating base 12 and the lower surface of the substrate W; and a nozzle cylindrical portion that extends downward from the nozzle disk portion. The ejection port of the lower surface nozzle 71 forms an opening at the central portion of the upper surface of the nozzle disk portion. When the substrate W is held by the rotating chuck 10, the ejection port of the lower surface nozzle 71 is vertically opposed to the central portion of the lower surface of the substrate W.

[0134] The lower surface nozzle 71 is connected to a heating fluid pipe 72 that guides warm water (pure water having a temperature higher than room temperature), which is an example of a heating fluid, to the lower surface nozzle 71. The pure water supplied to the lower surface nozzle 71 is heated by a heater 75 installed in the heating fluid pipe 72. When the heating fluid valve 73 installed in the heating fluid pipe 72 is opened, the warm water is continuously ejected upward from the ejection port of the lower surface nozzle 71 at a flow rate corresponding to the opening degree of the flow rate adjustment valve 74 that changes the flow rate of the warm water. Accordingly, the warm water is supplied to the lower surface of the substrate W.

[0135] 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. The pure water supplied to the lower surface nozzle 71 is cooled by a cooler 79 installed in the cooling fluid pipe 76. When the cooling fluid valve 77 installed in the cooling fluid pipe 76 is opened, the cold water is continuously ejected upward from the ejection port of the lower surface nozzle 71 at a flow rate corresponding to the opening degree of the flow rate adjustment valve 78 that changes the flow rate of the cold water. Accordingly, the cold water is supplied to the lower surface of the substrate W.

[0136] The outer peripheral surface of the lower surface nozzle 71 and the inner peripheral surface of the rotary base 12 form a lower gas flow path 82 in the shape of a cylinder extending vertically. The lower gas flow path 82 includes a lower central opening 81 formed at the center of the upper surface 12u of the rotary base 12. The lower gas flow path 82 is connected to a lower gas pipe 83 that introduces an inert gas into the lower central opening 81 of the rotary base 12. The substrate processing apparatus 1 may also include a lower temperature regulator 86 that heats or cools the inert gas ejected from the lower central opening 81 of the rotary base 12. When the lower gas valve 84 installed in the lower gas pipe 83 is opened, the inert gas is continuously ejected upward from the lower central opening 81 of the rotary base 12 at a flow rate corresponding to the opening degree of the flow rate adjustment valve 85 that changes the flow rate of the inert gas.

[0137] The inert gas ejected from the lower central opening 81 of the rotary base 12 is nitrogen. The inert gas ejected from the lower central opening 81 of the rotary base 12 may also be a gas other than nitrogen, such as helium or argon. When the substrate W is held by the rotary chuck 10, if nitrogen is ejected from the lower central opening 81 of the rotary base 12, the nitrogen flows radially in all directions between the lower surface of the substrate W and the upper surface 12u of the rotary base 12. Accordingly, the space between the substrate W and the rotary base 12 is filled with nitrogen.

[0138] Next, the film thickness measurement unit 91 will be described.

[0139] Figure 3 It is a schematic view for horizontally observing the film thickness measurement unit 91, the rotary chuck 10, and the blocking member 51. Figure 4 It is a schematic view for observing the film thickness measurement unit 91 and the rotary chuck 10 from above. Figure 5 It is a cross-sectional view showing the inside of the housing 93 that houses the light-emitting element 92. Figure 6 It is shown along Figure 5 The cross-sectional view of the cross-section along the VI-VI line shown.

[0140] As Figure 3 And Figure 4 As shown in

[0141] The light-emitting element 92 is disposed within the housing 93. The light-receiving element 97 is disposed within the housing 98. The light of the light-emitting element 92 is emitted from the opening of the housing 93 covered by the transparent plate 94 to the outside of the housing 93. The light of the light-emitting element 92 reflected by the upper surface of the substrate W passes through the opening of the housing 98 covered by the transparent plate 99 and is incident on the light-receiving element 97 within the housing 98. Figure 3 and Figure 4 The black dot Pi in Figure 4 indicates the incident position where the light of the light-emitting element 92 is incident on the upper surface of the substrate W. The thickness of the liquid film on the substrate W is calculated based on the light incident on the light-receiving element 97.

[0142] As Figure 5 and Figure 6 shown, 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 relative to the housing 93. The holder 95 and the electric motor 96 are housed within the housing 93. The rotor and stator of the electric motor 96 are housed within the motor housing 96a, and the rotation shaft 96b of the electric motor 96 protrudes from the end surface of the motor housing 96a in the axial direction of the electric motor 96. The rotation shaft 96b is connected to the holder 95, and the motor housing 96a is connected to the housing 93.

[0143] The rotation angle of the electric motor 96 is controlled by the controller 3. When the electric motor 96 rotates the rotation shaft 96b, the holder 95 and the light-emitting element 92 rotate together about a rotation axis A2 that is horizontal with respect to the housing 93. Figure 5 The white arrow in Figure 5 indicates the rotation of the light-emitting element 92 about the rotation axis A2. Accordingly, the incident position where the light of 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 of the light-emitting element 92 with respect to the upper surface of the substrate W changes. Therefore, if the electric motor 96 is rotated, the light of the light-emitting element 92 can be incident on multiple positions within the upper surface of the substrate W, and the film thickness can be measured at multiple positions within the upper surface of the substrate W.

[0144] If the incident position and the incident angle change, it means that the path through which the reflected light of the light of the light-emitting element 92 reflected by the upper surface of the substrate W passes also changes. The light-receiving element 97 can also be moved in such a way that it can receive the reflected light even if the path of the reflected light changes. For example, similar to the light-emitting element 92, an electric motor that moves the light-receiving element 97 relative to the housing 98 can also be provided. Alternatively, multiple light-receiving elements 97 corresponding to one light-emitting element 92 can also be provided. In these cases, even if the incident position and the incident angle change, the reflected light will be received by the light-receiving element 97, and the thickness of the liquid film on the substrate W can be measured.

[0145] When measuring the thickness of the liquid film on the substrate W, the controller 3 can rotate the substrate W on the rotary chuck 10 while keeping the incident position at a fixed distance from the rotation axis A1 in the horizontal direction, or move the incident position in the radial direction of the substrate W (the horizontal direction orthogonal to the rotation axis A1). In the latter case, the average value of a plurality of measurement values can also be treated as the film thickness.

[0146] Next, the pre-drying treatment liquid supply device 101 will be described. Figure 7 It is a schematic diagram showing the pre-drying treatment liquid supply device 101 included in the substrate processing apparatus 1.

[0147] 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 nozzle 39 via the pre-drying treatment liquid pipe 40. The pre-drying treatment liquid supply device 101 includes: a first tank 102A, which corresponds to a stock solution tank for storing the stock solution of the pre-drying treatment liquid; and a second tank 102B, which corresponds to a solvent tank for storing the solvent of the pre-drying treatment liquid.

[0148] The stock solution of the pre-drying treatment liquid contains a sublimable substance and a solvent. The concentration of the sublimable substance in the stock solution of the pre-drying treatment liquid is higher than that of the pre-drying treatment liquid supplied to the substrate W. The stock solution of the pre-drying treatment liquid is diluted with the solvent supplied from the second tank 102B and then supplied to the substrate W. When the sublimable substance is a liquid at room temperature, the stock solution of the pre-drying treatment liquid may not contain a solvent.

[0149] The pre-drying treatment liquid supply device 101 includes: a first circulation pipe 103A that circulates the stock solution in the first tank 102A; a first pump 104A that sends the stock solution in the first tank 102A to the first circulation pipe 103A; and a first individual pipe 105A that guides the stock solution in the first circulation pipe 103A to the pre-drying treatment liquid pipe 40. The pre-drying treatment liquid supply device 101 further includes: a first on-off valve 106A that opens and closes the inside of the first individual pipe 105A; and a first flow rate adjustment valve 107A that changes the flow rate of the pre-drying treatment liquid supplied from the first individual pipe 105A to the pre-drying treatment liquid pipe 40.

[0150] 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 pre-drying treatment liquid pipe 40. The pre-drying treatment liquid supply device 101 further includes: a second on-off valve 106B that opens and closes the inside of the second individual pipe 105B; and a second flow rate adjustment valve 107B that changes the flow rate of the pre-drying treatment liquid supplied from the second individual pipe 105B to the pre-drying treatment liquid pipe 40.

[0151] 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 stock solution of the pre-drying treatment liquid and the solvent. In the pre-drying treatment liquid pipe 40, not only a pre-drying treatment liquid valve 41 is installed, but also an in-pipe mixer 109 is installed. The in-pipe mixer 109 further mixes the pre-drying treatment liquid generated by the mixing valve 108. Accordingly, the pre-drying treatment liquid obtained by uniformly mixing the sublimable substance and the solvent is supplied to the pre-drying treatment liquid nozzle 39.

[0152] The stock 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 adjustment valve 107A. The solvent supplied from the second tank 102B is supplied to the mixing valve 108 at a flow rate corresponding to the opening degree of the second flow rate adjustment valve 107B. Therefore, by changing the opening degrees of the first flow rate adjustment valve 107A and the second flow rate adjustment 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.

[0153] The pre-drying treatment liquid supply device 101 is provided with a concentration meter 110 that measures 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 is provided with a measurement pipe 111 branched from the pre-drying treatment liquid pipe 40. The concentration meter 110 is installed in the measurement pipe 111. Figure 7 An example is shown in which the measurement pipe 111 is connected to the pre-drying treatment liquid pipe 40 at a position downstream of the in-pipe mixer 109. Therefore, in this example, the concentration of the pre-drying treatment liquid passing through both the mixing valve 108 and the in-pipe mixer 109 is measured by the concentration meter 110. The concentration meter 110 may be installed in the pre-drying treatment liquid pipe 40 between the pre-drying treatment liquid valve 41 and the in-pipe mixer 109 instead of being installed in the measurement pipe 111.

[0154] Figure 8 It is a block diagram showing the hardware of the controller 3.

[0155] The controller 3 is a computer including a computer main body 3a and a peripheral device 3d connected to the computer main body 3a. The computer main body 3a includes a CPU 3b (central processing unit: central processing device) 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 a program P, a reading device 3f that reads information from a removable medium RM, and a communication device 3g that communicates with other devices such as a main computer.

[0156] The controller 3 is connected to an input device 100A, a display device 100B, and an alarm device 100C. The input device 100A is operated by an operator such as a user or a maintenance person when inputting information into the substrate processing device 1. Information is displayed on the screen of the display device 100B. The input device 100A can be any one of a keyboard, a pointing device, and a touch panel, or can be a device other than them. A touch panel display that combines the input device 100A and the display device 100B can also be provided in the substrate processing device 1. The alarm device 100C issues an alarm using one or more of light, sound, text, and graphics. When the input device 100A is a touch panel display, the input device 100A can also function as the alarm device 100C.

[0157] The CPU 3b executes the program P stored in the auxiliary storage device 3e. The program P in the auxiliary storage device 3e can be a program pre-installed in the controller 3, a program sent from the removable medium RM to the auxiliary storage device 3e via the reading device 3f, or a program sent from an external device such as a main computer to the auxiliary storage device 3e via the communication device 3g.

[0158] The auxiliary storage device 3e and the removable medium RM are non-volatile memories that retain storage even without power supply. 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 non-temporary tangible recording medium.

[0159] The auxiliary storage device 3e stores a plurality of processing schemes. A processing scheme is information that specifies the processing content, processing conditions, and processing order of the substrate W. The plurality of processing schemes are different from each other in at least one of the processing content, processing conditions, and processing order of the substrate W. The controller 3 controls the substrate processing device 1 so as to process the substrate W according to the processing scheme specified by the main computer. The following respective processes are executed by the controller 3 controlling the substrate processing device 1. In other words, the controller 3 is programmed to execute the following respective processes.

[0160] Next, an example of substrate processing will be described.

[0161] The substrate W to be processed is, for example, a semiconductor wafer such as a silicon wafer. The surface of the substrate W corresponds to a device formation surface on which devices such as transistors and capacitors are formed. The substrate W can be a substrate W on which a pattern PA (refer to Fig. 10A ) is formed on the device formation surface, i.e., the surface of the substrate W, or a substrate W on which no pattern PA is formed on the surface of the substrate W. In the latter case, the pattern PA can also be formed by the liquid supply process described later.

[0162] First, an example of substrate processing (the first substrate processing example) when the pre-drying treatment liquid is a solution of camphor and IPA will be described.

[0163] Fig. 9 It is a process diagram for explaining the substrate processing performed by the substrate processing apparatus 1. Figures 10A to 10F It is a schematic diagram showing the state of the substrate W when using a solution of camphor and IPA. Fig.11 It is an equilibrium state diagram of camphor and IPA. Fig.11 In Figure 2 and Fig. 9 . Hereinafter, refer to Figures 10A to 10F and Fig.11 as appropriate.

[0164] When processing the substrate W by the substrate processing apparatus 1, a loading process (step S1 of Fig. 9 ) is performed to load the substrate W into the chamber 4.

[0165] Specifically, in a state where the shielding member 51 is in the upper position, all the sheaths 24 are in the lower position, and all the scanning nozzles are in the standby position, the central robot CR (refer to FIG. 1) supports the substrate W with the hand H1 and enters the hand H1 into the chamber 4. Then, the central 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. Thereafter, the plurality of chuck pins 11 are pressed against the outer peripheral surface of the substrate W to hold the substrate W. Accordingly, the substrate W is held by rotating the chuck 10 (substrate holding process). The substrate holding process continues until the sublimation process (step S10 of Fig. 9 ) described later ends. After the central robot CR places the substrate W on the rotating chuck 10, the hand H1 is withdrawn from the inside of the chamber 4.

[0166] Next, the upper gas valve 64 and the lower gas valve 84 are opened, and nitrogen gas starts to be ejected from the upper central opening 61 of the shielding member 51 and the lower central opening 81 of the rotary base 12. Accordingly, the space between the substrate W and the shielding member 51 is filled with nitrogen gas. Similarly, the space between the substrate W and the rotary base 12 is filled with nitrogen gas. On the other hand, the sheath lifting unit 27 raises at least one sheath 24 from the lower position to the upper position. Thereafter, the rotary motor 14 is driven to start rotating the substrate W at a predetermined liquid supply speed (substrate rotation process). The substrate rotation process continues until the sublimation process ( Fig. 9 step S10) described later ends.

[0167] Next, a chemical solution supply process ( Fig. 9 step S2) is performed to supply a chemical solution to the upper surface of the substrate W to form a liquid film of the chemical solution covering the entire area of the upper surface of the substrate W.

[0168] Specifically, in a state where the shielding member 51 is in the upper position and at least one sheath 24 is in the upper position, the nozzle moving unit 34 moves the chemical solution nozzle 31 from the standby position to the processing position. Thereafter, the chemical solution valve 33 is opened, and the chemical solution nozzle 31 starts to eject the chemical solution (chemical solution supply process, chemical solution ejection process). When a predetermined time has elapsed after the chemical solution valve 33 is opened, the chemical solution valve 33 is closed to stop ejecting the chemical solution. Thereafter, the nozzle moving unit 34 moves the chemical solution nozzle 31 to the standby position.

[0169] The chemical solution ejected from the chemical solution nozzle 31 collides with the upper surface of the substrate W rotating at a predetermined chemical solution supply speed and then flows outward along the upper surface of the substrate W by centrifugal force. Accordingly, the chemical solution is supplied to the entire area of the upper surface of the substrate W to form a liquid film of the chemical solution covering the entire area of the upper surface of the substrate W. When the chemical solution nozzle 31 ejects the chemical solution, the nozzle moving unit 34 can move the liquid contact position so that the liquid contact position of the chemical solution with respect to the upper surface of the substrate W passes through the central portion and the outer peripheral portion, or can make the liquid contact position stationary at the central portion.

[0170] Next, a rinsing process ( Fig. 9 step S3) is performed to supply pure water, which is an example of a rinsing liquid, to the upper surface of the substrate W to rinse the chemical solution on the substrate W.

[0171] Specifically, in a state where the blocking member 51 is in the upper position and at least one sheath 24 is in the upper position, the nozzle moving unit 38 moves the rinse liquid nozzle 35 from the standby position to the processing position. Thereafter, the rinse liquid valve 37 is opened, and the rinse liquid nozzle 35 starts to eject the rinse liquid (rinse liquid supply process, rinse liquid ejection process). Before starting to eject pure water, in order to replace the sheath 24 that receives the liquid discharged from the substrate W, the sheath lifting unit 27 may also vertically move at least one sheath 24. When a predetermined time has elapsed after the rinse liquid valve 37 is opened, the rinse liquid valve 37 is closed, and the ejection of the rinse liquid is stopped. Thereafter, the nozzle moving unit 38 moves the rinse liquid nozzle 35 to the standby position.

[0172] The pure water ejected from the rinse liquid nozzle 35 collides with the upper surface of the substrate W that is rotating at a predetermined rinse liquid supply speed, and then flows outward along the upper surface of the substrate W by centrifugal force. The chemical liquid on the substrate W is replaced with the pure water ejected from the rinse liquid nozzle 35. Accordingly, a liquid film of pure water covering the entire area of the upper surface of the substrate W is formed. When the rinse liquid nozzle 35 ejects pure water, the nozzle moving unit 38 may move the liquid contact position so that the pure water passes through the central portion and the outer peripheral portion with respect to the liquid contact position on the upper surface of the substrate W, or may make the liquid contact position stationary at the central portion.

[0173] Next, a replacement process step ( Fig. 9 step S4) is performed, in which a replacement liquid that is miscible with both the rinse liquid and the pre-drying treatment liquid is supplied to the upper surface of the substrate W, and the pure water on the substrate W is replaced with the replacement liquid.

[0174] Specifically, in a state where the blocking member 51 is in the upper position and at least one sheath 24 is in the upper position, the nozzle moving unit 46 moves the replacement liquid nozzle 43 from the standby position to the processing position. Thereafter, the replacement liquid valve 45 is opened, and the replacement liquid nozzle 43 starts to eject the replacement liquid (replacement liquid supply process, replacement liquid ejection process). Before starting to eject the replacement liquid, in order to replace the sheath 24 that receives the liquid discharged from the substrate W, the sheath lifting unit 27 may also vertically move at least one sheath 24. When a predetermined time has elapsed after the replacement liquid valve 45 is opened, the replacement liquid valve 45 is closed, and the ejection of the replacement liquid is stopped. Thereafter, the nozzle moving unit 46 moves the replacement liquid nozzle 43 to the standby position.

[0175] After the replacement liquid ejected from the replacement liquid nozzle 43 collides with the upper surface of the substrate W rotating at a predetermined replacement liquid supply speed, it flows outward along the upper surface of the substrate W by centrifugal force. The pure water on the substrate W is replaced with the replacement liquid ejected from the replacement liquid nozzle 43. Accordingly, a liquid film of the replacement liquid covering the entire area of the upper surface of the substrate W is formed. When the replacement liquid nozzle 43 ejects the replacement liquid, the nozzle moving unit 46 can move the liquid contact position so that the liquid contact position of the replacement liquid with respect to the upper surface of the substrate W passes through the central portion and the outer peripheral portion, or can make the liquid contact position stationary at the central portion. Further, after forming the liquid film of the replacement liquid covering the entire area of the upper surface of the substrate W, the substrate W can be rotated at an immersion speed (for example, a speed exceeding 0 and 20 rpm or less) while stopping the replacement liquid nozzle 43 from ejecting the replacement liquid.

[0176] Next, a pre-drying treatment liquid supply step ( Fig. 9 step S5) is performed to supply the pre-drying treatment liquid to the upper surface of the substrate W and form a liquid film of the pre-drying treatment liquid on the substrate W.

[0177] Specifically, in a state where the blocking member 51 is in the upper position and at least one sheath 24 is in the upper position, the nozzle moving unit 42 moves the pre-drying treatment liquid nozzle 39 from the standby position to the treatment position. Thereafter, the pre-drying treatment liquid valve 41 is opened, and the pre-drying treatment liquid nozzle 39 starts to eject the pre-drying treatment liquid (pre-drying treatment liquid supply step, pre-drying treatment liquid ejection step). Before starting to eject the pre-drying treatment liquid, the sheath lifting unit 27 can vertically move at least one sheath 24 in order to replace the sheath 24 that receives the liquid discharged from the substrate W. When a predetermined time has elapsed after the pre-drying treatment liquid valve 41 is opened, the pre-drying treatment liquid valve 41 is closed, and the ejection of the pre-drying treatment liquid is stopped. Thereafter, the nozzle moving unit 42 moves the pre-drying treatment liquid nozzle 39 to the standby position.

[0178] After the pre-drying treatment liquid ejected 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 flows outward along the upper surface of the substrate W by centrifugal force. The pre-drying treatment liquid supply speed is, for example, 500 rpm. The replacement liquid on the substrate W is replaced with the pre-drying treatment liquid ejected from the pre-drying treatment liquid nozzle 39. Accordingly, a liquid film of the pre-drying treatment liquid covering the entire area of the upper surface of the substrate W (pre-drying treatment liquid film 120) is formed (pre-drying treatment liquid film forming step). In this way, 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 to the upper surface of the substrate W in such a manner as to form the pre-drying treatment liquid film 120 on the upper surface of the substrate W.

[0179] When the pre-drying treatment liquid nozzle 39 ejects the pre-drying treatment liquid, the nozzle moving unit 42 can move the liquid contact position in such a way that the liquid contact position of the pre-drying treatment liquid with respect to the upper surface of the substrate W passes through the central part and the outer peripheral part, or can make the liquid contact position stationary at the central part.

[0180] Next, a film thickness reduction step ( Fig. 9 step S6) is performed. While maintaining the state where the entire area of the upper surface of the substrate W is covered with the liquid film of the pre-drying treatment liquid, the thickness (film thickness) of the pre-drying treatment liquid film 120 on the substrate W is reduced.

[0181] Specifically, the shutter member lifting unit 54 moves the shutter member 51 from the upper position to the lower position. Then, in the state where the shutter member 51 is in the lower position and at least one sheath 24 is in the upper position, the rotation motor 14 maintains the rotation speed of the substrate W at the film thickness reduction rotation speed. The film thickness reduction rotation speed may be equal to or different from the pre-drying treatment liquid supply speed. After the pre-drying treatment liquid stops being ejected onto the substrate W, the pre-drying treatment liquid on the substrate W is also discharged outward from the substrate W by centrifugal force. 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 a certain extent, the discharge amount of the pre-drying treatment liquid from the substrate W per unit time is reduced to zero or approximately zero. Accordingly, the thickness of the pre-drying treatment liquid film 120 on the substrate W stabilizes at a value corresponding to the rotation speed of the substrate W.

[0182] After reducing the thickness of the pre-drying treatment liquid film 120 by using the film thickness reduction step ( Fig. 9 step S6), a first precipitation step (precipitation step) ( Fig. 9 step S7) is performed to precipitate the solid 121 of the sublimable substance (refer to Fig. 10B ) into the pre-drying treatment liquid on the substrate W.

[0183] Specifically, in the state where the shutter member 51 is in the lower position and at least one sheath 24 is in the upper position, the rotation motor 14 maintains the rotation speed of the substrate W at a predetermined first precipitation speed. The first precipitation speed may be equal to or different from the pre-drying treatment liquid supply speed. The first precipitation speed is, for example, 500 rpm. Since the vapor pressure of the solvent is higher than the vapor pressure of the sublimable substance, during the rotation of the substrate W at the first precipitation speed, the solvent evaporates from the surface of the pre-drying treatment liquid at an evaporation speed greater than the evaporation speed of the sublimable substance. Fig. 10A Indicates the state where the solvent evaporates from the surface of the pre-drying treatment liquid.

[0184] If the evaporation of the solvent continues, the thickness of the pre-drying treatment liquid film 120 gradually decreases, and at the same time, the concentration of the sublimable substance on the surface of and in the vicinity of the pre-drying treatment liquid film 120 gradually increases. The evaporation of the solvent from the pre-drying treatment liquid film 120 is carried out, for example, without forcibly heating the pre-drying treatment liquid film 120 on the substrate W. 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 a temperature slightly lower than room temperature. When the concentration of the sublimable substance on the surface of and in the vicinity of the pre-drying treatment liquid film 120 reaches the saturation concentration of the sublimable substance in the pre-drying treatment liquid, as Fig. 10B shown, the solid 121 of the sublimable substance precipitates on the surface of the pre-drying treatment liquid film 120 (room temperature precipitation process, liquid surface precipitation process). In the first precipitation process, the rotation motor 14 functions as a solvent evaporation unit that evaporates the solvent from the pre-drying treatment liquid film 120 in such a way that the solid 121 of the sublimable substance precipitates.

[0185] As Fig. 10B shown, when the solid 121 of the sublimable substance precipitates, all or part of the pre-drying treatment liquid located in the main body of the pre-drying treatment liquid, in other words, in the range from the surface (liquid surface) of the pre-drying treatment liquid film 120 to the upper surface of the pattern PA, becomes the solid 121 of the sublimable substance. Fig. 10B An example is shown in which 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 becomes the solid 121 of the sublimable substance, and the remaining pre-drying treatment liquid film 120 remains in a liquid state. In this example, the solid 121 of the sublimable substance does not reach the upper surface of the pattern PA, and the pre-drying treatment liquid remains not only between the patterns PA but also between the solid 121 of the sublimable substance and the upper surface of the pattern PA. All or part of the surface of the pre-drying treatment liquid film 120 is covered with a horizontally extended film-like solid 121 of the sublimable substance, in other words, with a solidified film (solid film).

[0186] Next, the first dissolution process ( Fig. 9 step S8) is carried out to dissolve the solid 121 of the sublimable substance in the pre-drying treatment liquid on the substrate W.

[0187] Specifically, in a state where the blocking member 51 is in the lower position and at least one sheath 24 is in the upper position, the rotation motor 14 maintains the rotation speed of the substrate W at a predetermined first dissolution speed. The first dissolution speed may be equal to or different from the supply speed of the drying pretreatment liquid before drying. The first dissolution speed is, for example, 500 rpm. Further, the heating fluid valve 73 is opened, and the lower surface nozzle 71 starts to eject warm water (pure water with a temperature higher than room temperature). Before starting to eject warm water, the sheath lifting unit 27 may vertically move at least one sheath 24 in order to replace the sheath 24 that receives the liquid discharged from the substrate W.

[0188] After the warm water ejected from the lower surface nozzle 71 collides with the central portion of the lower surface of the substrate W rotating at the first dissolution speed, it flows outward along the lower surface of the substrate W. Accordingly, the entire area of the substrate W is heated at a heating temperature higher than room temperature. The heat of the warm water is transferred to the drying pretreatment liquid on the substrate W via the substrate W. The drying pretreatment liquid film 120 on the substrate W is indirectly heated through the substrate W (indirect heating process). Accordingly, the temperature of the solid 121 of the sublimable substance and the drying pretreatment liquid film 120 on the substrate W is maintained at a temperature higher than room temperature.

[0189] As Fig. 10C shown, when the temperature of the drying pretreatment liquid film 120 on the substrate W rises, the saturation concentration of the sublimable substance in the drying pretreatment liquid rises, and the solid 121 of the sublimable substance dissolves in the drying pretreatment liquid on the substrate W. The dissolution of the solid 121 of the sublimable substance in the drying pretreatment liquid is promoted by the rise in the temperature of the drying pretreatment liquid. Accordingly, all or most of the solid 121 of the sublimable substance dissolves in the drying pretreatment liquid on the substrate W. Fig. 10D An example in which all of the solid 121 of the sublimable substance is dissolved in the drying pretreatment liquid is shown.

[0190] After dissolving the solid 121 of the sublimable substance in the drying pretreatment liquid, the solid 121 of the sublimable substance may be precipitated again, and the precipitated solid 121 of the sublimable substance may be dissolved in the drying pretreatment liquid again. In other words, it is also possible to perform two or more times a repetition cycle from the first precipitation step ( Fig. 9 step S7) to the first dissolution step ( Fig. 9 step S8).

[0191] Fig. 9 "N" in Fig. 9 refers to an integer of 0 or more. When N is 1 or more, two or more repetition cycles are performed, and thereafter, the final precipitation step ( Fig. 9 step S9) is performed. When N is 0, the first precipitation step ( Fig. 9 step S7) and the first dissolution step ( Fig. 9Then, a final precipitation step ( Fig. 9 Step S9).

[0192] Specifically, when the blocking member 51 is in the lower position and at least one of the sheaths 24 is in the upper position, the rotating motor 14 maintains the rotation speed of the substrate W at a predetermined final precipitation speed. The final precipitation speed may be equal to or different from the supply speed of the pre-drying treatment liquid. The final precipitation speed is, for example, 500 rpm. The warm water is sprayed from the lower surface nozzle 71 from the first dissolution step ( Fig. 9 Therefore, the drying pre-treatment liquid on the substrate W is also maintained at a temperature higher than the room temperature during the period when the substrate W is rotated at the final deposition speed.

[0193] like Fig. 10D As shown, during the period when the substrate W rotates at the final precipitation speed, the solvent evaporates from the surface of the drying pre-treatment liquid film 120. Therefore, the surface of the drying pre-treatment liquid gradually approaches the base of the pattern PA, and the concentration of the sublimable substance in the drying pre-treatment liquid film 120 gradually increases. When the concentration of the sublimable substance in the drying pre-treatment liquid film 120 reaches the saturation concentration of the sublimable substance in the drying pre-treatment liquid, the solid 121 of the sublimable substance is precipitated on the upper surface of the substrate W, and all or almost all of the drying pre-treatment liquid disappears from the substrate W. In the final precipitation step, the rotary motor 14 and the lower surface nozzle 71 function as a solvent evaporation unit that evaporates the solvent from the drying pre-treatment liquid film 120 in a manner that the solid 121 of the sublimable substance is precipitated.

[0194] Fig.10E An example is shown in which all the pre-drying treatment liquid disappears and the solid 121 of the sublimable substance is precipitated between the patterns PA. Fig.10E An example is shown in which the thickness of the solid 121 of the sublimable substance is larger than the height of the pattern PA.

[0195] Fig.11 This is the equilibrium diagram of camphor and IPA. The solution of camphor and IPA is equivalent to the pre-drying treatment solution. Fig.11 The curve in (freezing curve) represents the freezing point of the solution of camphor and IPA. Fig.11 The bold line in the figure indicates that the first precipitation step is performed once ( Fig. 9 Step S7), the first dissolution step ( Fig. 9 Step S8) and the final precipitation step ( Fig. 9 In step S9), that is, Fig. 9 The concentration of camphor and the temperature of the solution when N=0.

[0196] exist Fig.11In this, the thick straight line from point P1 to point P2 represents performing the first precipitation step ( Fig. 9 step S8). When performing the first precipitation step ( Fig. 9 step S8), IPA evaporates from the solution of camphor and IPA corresponding to the pre-drying treatment liquid, and the concentration of camphor slowly rises. At this time, the temperature of the pre-drying treatment liquid is maintained at room temperature or a temperature near it. When the concentration of camphor rises to the concentration at point P2 in Fig.11 , a solid 121 containing a sublimable substance of camphor and IPA is formed by precipitation or solidification.

[0197] In Fig.11 , the thick straight line from point P2 to point P3 represents performing the first dissolution step ( Fig. 9 step S8). When performing the first dissolution step ( Fig. 9 step S8), the temperature of the solution of camphor and IPA rises, and the temperature of the solid 121 of the sublimable substance rises to a temperature higher than the freezing point of the solution of camphor and IPA. Accordingly, at least a part of the solid 121 of the sublimable substance melts or dissolves and returns to the solution of camphor and IPA.

[0198] In Fig.11 , the thick straight line from point P3 to point P4 represents performing the final precipitation step ( Fig. 9 step S9). As described above, when performing the final precipitation step ( Fig. 9 step S9), in order to precipitate the solid 121 of the sublimable substance again, instead of lowering the temperature of the solution of camphor and IPA, while maintaining the solution of camphor and IPA at a temperature higher than room temperature, IPA is further evaporated. Therefore, a solid 121 of a sublimable substance with a lower IPA content than the solid 121 of the sublimable substance precipitated in the first precipitation step ( Fig. 9 step S7) precipitates.

[0199] After the solid 121 of the sublimable substance is precipitated between the patterns PA, a sublimation step ( Fig. 9 step S10) is performed to sublime the solid 121 of the sublimable substance and remove it from the upper surface of the substrate W.

[0200] Specifically, in a state where the shielding member 51 is in the lower position, the rotation motor 14 maintains the rotation speed of the substrate W at a predetermined sublimation speed. The sublimation speed may be equal to or different from the supply speed of the pre-drying treatment liquid. The sublimation speed is, for example, 1500 rpm. Further, the upper gas valve 57 is opened, and the central nozzle 55 starts to eject nitrogen. It is also possible to, in addition to or instead of opening the upper gas valve 57, change the opening degree of the flow rate adjustment valve 65 to increase the flow rate of nitrogen ejected from the upper central opening 61 of the shielding member 51.

[0201] When starting the rotation of the substrate W at the sublimation speed or the like, sublimation of the solid 121 of the sublimable substance on the substrate W begins, and a gas containing the sublimable substance is generated from the solid 121 of the sublimable substance on the substrate W. The gas (gas containing the sublimable substance) generated from the solid 121 of the sublimable substance flows radially in the space between the substrate W and the blocking member 51 and is discharged from above the substrate W. Then, when a certain amount of time has passed after the start of sublimation, as Fig.10F shown, all the solid 121 of the sublimable substance is removed from the substrate W. Thereafter, the rotation motor 14 stops, and the rotation of the substrate W is stopped. Further, the upper gas valve 57 is closed, and the central nozzle 55 stops ejecting nitrogen.

[0202] In this way, the central nozzle 55, the upper central opening 61 of the blocking member 51, and the rotation motor 14 function as a sublimation unit for sublimating the solid 121 of the sublimable substance on the upper surface of the substrate W.

[0203] It should be noted that instead of ejecting the above-mentioned nitrogen, a heat source such as a heating element or a lamp may be disposed above or below the substrate W, and the sublimable substance is sublimated by heating using these heat sources.

[0204] In addition, although it will be described below, when the solid 121 of the sublimable substance precipitates on the substrate W, the detection value of the film thickness measuring unit 91 changes greatly. Therefore, the controller 3 can determine whether the solid 121 of the sublimable substance has precipitated by monitoring the detection value of the film thickness measuring unit 91. Therefore, the controller 3 can also control in the following manner: a threshold value is preset for the film thickness at any position within the upper surface of the substrate W measured by the film thickness measuring unit 91, and if the measured film thickness becomes below the threshold value, the process shifts from the final precipitation process to the sublimation process.

[0205] Next, the unloading process ( Fig. 9 step S11) is performed to unload the substrate W from the chamber 4.

[0206] Specifically, the blocking member lifting unit 54 raises the blocking member 51 to the upper position, and the sheath lifting unit 27 lowers all the sheaths 24 to the lower position. Further, 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 rotating base 12 stop ejecting nitrogen. Thereafter, the central robot CR makes the hand H1 enter the chamber 4. After the central robot CR releases the holding of the substrate W by the plurality of chuck pins 11, the hand H1 supports the substrate W on the rotating chuck 10. Thereafter, while the central robot CR supports the substrate W with the hand H1, the hand H1 is withdrawn from the inside of the chamber 4. Accordingly, the processed substrate W is unloaded from the chamber 4.

[0207] Next, an example of substrate treatment when the pre-drying treatment liquid is a solution of camphor and methanol (the second substrate treatment example) will be described.

[0208] The general process of the second substrate treatment example is the same as that of the first substrate treatment example, as Fig. 9 shown. For the second substrate treatment example, the processes from the first dissolution step ( Fig. 9 step S8) to the final precipitation step ( Fig. 9 step S9) are different from those of the first substrate treatment example, and the other processes are the same as those of the first substrate treatment example. Therefore, hereinafter, the processes from the first dissolution step to the final precipitation step in the second substrate treatment example will be described.

[0209] FIG. 12A to FIG. 12D is a schematic diagram showing the state of the substrate W when using a solution of camphor and methanol. Hereinafter, refer to Figure 2 and Fig. 9 . Regarding FIG. 12A to FIG. 12D , refer appropriately.

[0210] After the solid 121 of the sublimable substance is precipitated by the first precipitation step at the beginning ( Fig. 9 step S7), the first dissolution step ( Fig. 9 step S8) is performed to dissolve the solid 121 of the sublimable substance in the pre-drying treatment liquid on the substrate W.

[0211] Specifically, in a state where the shielding member 51 is in the lower position and at least one sheath 24 is in the upper position, the rotation motor 14 maintains the rotation speed of the substrate W at a predetermined first dissolution speed. The first dissolution speed may be equal to or different from the pre-drying treatment liquid supply speed. The first dissolution speed is, for example, 1500 rpm. When the substrate W rotates at the first dissolution speed, in order to stop the nitrogen gas from spraying out from the upper central opening 61 of the shielding member 51, the controller 3 may also close the upper gas valve 64. Alternatively, the controller 3 may reduce the flow rate of the nitrogen gas spraying out from the upper central opening 61 of the shielding member 51 by changing the opening degree of the flow rate adjustment valve 65.

[0212] When the solvent evaporates from the pre-drying treatment liquid in the first precipitation step ( Fig. 9 step S7), the heat of the pre-drying treatment liquid equivalent to the heat of vaporization is released into the gas atmosphere in the chamber 4 together with the solvent, and the temperature of the surface of the pre-drying treatment liquid decreases. When the solid 121 of the sublimable substance is formed, the amount of the solvent evaporated from the pre-drying treatment liquid decreases, so the heat of the pre-drying treatment liquid released into the gas atmosphere also decreases. At the same time, as Fig. 12AAs shown, heat in the gas atmosphere is transferred to the pre-drying treatment liquid through the solid 121 of the sublimable substance. Accordingly, the temperature of the solid 121 of the sublimable substance and the pre-drying treatment liquid film 120 on the substrate W rises.

[0213] When the temperature of the solid 121 of the sublimable substance and the pre-drying treatment liquid film 120 on the substrate W rises, as Fig. 12B shown, a part of the solid 121 of the sublimable substance dissolves in the pre-drying treatment liquid. The pre-drying treatment liquid is a solution of camphor and methanol. The solid 121 of the sublimable substance contains camphor. The solubility of camphor in methanol is greater than the solubility of camphor in IPA, and camphor is easily soluble in methanol. When a part of the solid of camphor dissolves in the liquid of methanol, the remaining solid of camphor also immediately dissolves in the liquid of methanol. Accordingly, all or most of the solid 121 of the sublimable substance dissolves in the pre-drying treatment liquid on the substrate W. Fig. 12C An example in which the solid 121 of the sublimable substance completely dissolves in the pre-drying treatment liquid is shown.

[0214] When the solid 121 of the sublimable substance dissolves in the pre-drying treatment liquid on the substrate W, the solvent evaporated from the pre-drying treatment liquid increases, and the temperature of the surface of the pre-drying treatment liquid decreases. Accordingly, as Fig.12D shown, the concentration of the sublimable substance on the surface of the pre-drying treatment liquid rises, and the solid 121 of the sublimable substance precipitates again on the surface of the pre-drying treatment liquid ( Fig. 9 step S7). When the solid 121 of the sublimable substance precipitates again, as described above, the temperature of the solid 121 of the sublimable substance and the pre-drying treatment liquid rises, and the solid 121 of the sublimable substance dissolves in the pre-drying treatment liquid again ( Fig. 9 step S8).

[0215] Thus, when the pre-drying treatment liquid is a solution of camphor and methanol, even without forcibly changing the temperature of the pre-drying treatment liquid, the precipitation and dissolution of the solid 121 of the sublimable substance can be repeated (natural precipitation process, natural dissolution process) only by placing the pre-drying treatment liquid on the upper surface of the substrate W. The number of repetitions of one repetition cycle from the first precipitation process ( Fig. 9 step S7) to the first dissolution process ( Fig. 9 step S8) increases as the placement time of the pre-drying treatment liquid increases. Therefore, it is only necessary to set the number of repetitions of the precipitation and dissolution of the solid 121 of the sublimable substance according to the allowable time.

[0216] When precipitating the solid 121 of the sublimable substance, the vapor pressure of the solvent in the gas atmosphere in contact with the pre-drying treatment liquid on the substrate W is maintained to be less than the saturated vapor pressure of the solvent at the temperature of the gas atmosphere. When dissolving the solid 121 of the sublimable substance, the temperature at the interface between the solid 121 of the sublimable substance and the pre-drying treatment liquid film 120 is maintained to be a value exceeding the freezing point of the pre-drying treatment liquid at the concentration of the sublimable substance when dissolving the solid 121 of the sublimable substance. In this way, the precipitation and dissolution of the solid 121 of the sublimable substance are naturally repeated.

[0217] When precipitating and dissolving the solid 121 of the sublimable substance, the controller 3 may also cause at least one of the central nozzle 55 and the upper central opening 61 of the shut-off member 51 to eject a gas such as nitrogen at a low flow rate. 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 promoted. Furthermore, as long as a gas is ejected at a low flow rate onto the upper surface of the substrate W, the temperature change at the interface between the solid 121 of the sublimable substance and the pre-drying treatment liquid film 120 can be suppressed to a minimum. Therefore, the evaporation of the solvent can be promoted without hindering the dissolution of the solid 121 of the sublimable substance.

[0218] The FFU 6 always supplies clean air into the chamber 4. The downward flow of the clean air flowing onto the upper surface of the substrate W is blocked by the shut-off member 51. Accordingly, the disturbance of the gas atmosphere on the substrate W can be suppressed. The controller 3 may also temporarily stop the supply of clean air by the FFU 6 when precipitating and dissolving the solid 121 of the sublimable substance. In addition, in order to suppress the disturbance of the gas atmosphere on the substrate W, the controller 3 may also temporarily stop the rotation of the substrate W by the rotation motor 14 when precipitating and dissolving the solid 121 of the sublimable substance.

[0219] After dissolving the solid 121 of the sublimable substance in the pre-drying treatment liquid, a final precipitation process ( Fig. 9 step S9) is performed to precipitate the solid 121 of the sublimable substance again.

[0220] Specifically, in a state where the shut-off member 51 is in the lower position and at least one of the sheaths 24 is in the upper position, the rotation motor 14 maintains the rotation speed of the substrate W at a predetermined final precipitation speed. The final precipitation speed may be equal to or different from the supply speed of the pre-drying treatment liquid. The final precipitation speed is, for example, 1500 rpm. While the substrate W rotates at the final precipitation speed, the solvent evaporates from the surface of the pre-drying treatment liquid. When the concentration of the sublimable substance in the pre-drying treatment liquid reaches the saturated 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 liquid disappears from the substrate W (refer to Fig.10E)。Subsequently, a sublimation process of sublimating the solid 121 of the sublimable substance on the substrate W is performed ( Fig. 9 step S10).

[0221] As described above, when the pre-drying treatment liquid is a solution of camphor and methanol, the precipitation and dissolution of the solid 121 of the sublimable substance are repeated only by placing the pre-drying treatment liquid on the upper surface of the substrate W. When a small amount of the pre-drying treatment liquid remains on the substrate W, the solid 121 of the sublimable substance may dissolve in the pre-drying treatment liquid before the solid 121 of the sublimable substance is sublimated. To prevent this, the solid 121 of the sublimable substance on the substrate W can be cooled. For example, the rotation speed of the substrate W can be increased, or the flow rate of the gas ejected onto the upper surface of the substrate W can be increased.

[0222] Fig.13 is a graph showing the overturning rate of the pattern PA. The overturning rate A and the overturning rate B are values when the pre-drying treatment liquid is a solution of camphor and IPA, and the overturning rate C is a value when the pre-drying treatment liquid is a solution of camphor and methanol.

[0223] "Overturning rate A" is Fig. 9 different from the substrate treatment shown, and is the value when the solid 121 of the sublimable substance is precipitated once and then the solid 121 of the sublimable substance is sublimated. "Overturning rate B" is the value when the solid 121 of the sublimable substance is precipitated twice and then the solid 121 of the sublimable substance is sublimated. That is, "overturning rate B" is Fig. 9 the overturning rate in the case of N = 0 in

[0224] "Overturning rate C" is the value when the solid 121 of the sublimable substance is precipitated more than twice and then the solid 121 of the sublimable substance is sublimated. Except for the composition of the pre-drying treatment liquid and the number of times the solid 121 of the sublimable substance is precipitated, the treatment conditions of the substrate W in the overturning rates A to C are the same.

[0225] Since the collapse rate B is lower than the collapse rate A, if the solid 121 of the sublimable substance that has precipitated is dissolved in the pre-drying treatment liquid and then the solid 121 of the sublimable substance is precipitated again, the collapse rate of the pattern PA can be reduced. Since the collapse rate C is lower than the collapse rate B, when the sublimable substance is camphor, if methanol is used as the solvent instead of IPA, the collapse rate of the pattern PA can be further reduced. Therefore, even when the strength of the pattern PA is extremely low, as long as the first precipitation step ( Fig. 9 step S7) and the first dissolution step ( Fig. 9 step S8) are repeated in a cycle one or more times as in this embodiment, the collapse rate of the pattern PA can be reduced. That is, even when N = 0 in Fig. 9 , the collapse rate of the pattern PA can be reduced.

[0226] According to the research of the present inventors, when the interval G1 of the pattern PA (refer to Fig. 10A ) is 30 nm or less, there are cases where a good collapse rate of the pattern PA cannot be obtained even after sublimation drying. It is considered that the reason is that an incomplete precipitation region where the solid 121 of the sublimable substance does not exist or hardly exists is formed in the upper surface of the substrate W between the patterns PA. Therefore, if the solid 121 of the sublimable substance that has precipitated is dissolved in the pre-drying treatment liquid and then the solid 121 of the sublimable substance is precipitated again, the collapse rate of the pattern PA can be reduced even for the substrate W with the interval G1 of the pattern PA being 30 nm or less.

[0227] Next, the change in the thickness of the pre-drying treatment liquid film 120 will be described.

[0228] Fig.14 is a graph showing the change in the thickness of the pre-drying treatment liquid film 120 on the upper surface of the substrate W with time until the solid 121 of the sublimable substance precipitates from the pre-drying treatment liquid. Fig.14 The aspect ratio of the inset in Fig.14 is different from other parts in

[0229] Fig.14 The multiple curves (solid curve, single-dot dash curve, dashed curve) in Fig.14 are film thickness curves showing the measured values when using multiple pre-drying treatment liquids with different concentrations of the sublimable substance. Except for the concentration of the sublimable substance, the conditions for each measurement are the same. As shown in

[0230] In Fig.14In this case, the thickness of the pre-drying treatment liquid film 120 is only measured up to time T1. The reason is that at time T1, the solid 121 of the sublimable substance precipitates. In other words, the pre-drying treatment liquid is transparent, whereas the transparency of the solid 121 of the sublimable substance is lower than that of the pre-drying treatment liquid. Therefore, when the solid 121 of the sublimable substance precipitates, the detection value of the film thickness measurement unit 91 changes significantly, and the thickness of the pre-drying treatment liquid film 120 cannot be measured.

[0231] When the solid 121 of the sublimable substance precipitates, the detection value of the film thickness measurement unit 91 changes significantly. Therefore, the controller 3 can determine whether the solid 121 of the sublimable substance has precipitated by monitoring the detection value of the film thickness measurement unit 91. Furthermore, the thickness of the pre-drying treatment liquid film 120 immediately before the solid 121 of the sublimable substance precipitates is substantially equal to the thickness of the solid 121 of the sublimable substance immediately after the solid 121 of the sublimable substance has precipitated. Therefore, the controller 3 can also measure the thickness of the solid 121 of the sublimable substance by measuring the thickness of the pre-drying treatment liquid film 120.

[0232] In addition, as Fig.14 shown, regardless of the value of the concentration of the sublimable substance, the film thickness of the pre-drying treatment liquid decreases rapidly, and then decreases slowly. During the period when the film thickness of the pre-drying treatment liquid film 120 decreases rapidly, there is almost no difference in the film thickness and the film thickness reduction rate of the pre-drying treatment liquid in a plurality of pre-drying treatment liquids with different concentrations of the sublimable substance. In other words, as long as the time elapsed is the same, regardless of the concentration of the sublimable substance, the film thickness of the pre-drying treatment liquid film 120 decreases at a substantially same reduction rate.

[0233] In contrast, as Fig.14 shown in the inset in, during the period when the film thickness of the pre-drying treatment liquid film 120 decreases slowly, a difference in the film thickness reduction rate is observed in a plurality of pre-drying treatment liquids with different concentrations of the sublimable substance. It is considered that the reason is that if the concentration of the sublimable substance changes, the viscosity of the pre-drying treatment liquid changes.

[0234] 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 outside the substrate W by the centrifugal force generated by 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 curve graph. In other words, the higher the concentration of the sublimable substance in the pre-drying treatment liquid, the smaller the film thickness reduction rate during the period when the film thickness of the pre-drying treatment liquid film 120 decreases slowly. Therefore, in Fig.14In the inserted figure, 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 concentration of the sublimable substance in the pre-drying treatment liquid indicated by the single-dot chain line 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.

[0235] Therefore, as long as the film thickness reduction rates of a plurality of pre-drying treatment liquid films 120 with different concentrations of sublimable substances are measured in advance and prepared as reference data SD, by monitoring the thickness of the pre-drying treatment liquid film 120 on the substrate W, 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 (refer to Figure 8 ). In order to compare with the film thickness reduction rate obtained by monitoring the thickness of the pre-drying treatment liquid film 120 on the substrate W during substrate processing, the reference data SD stored in the main storage device 3c is referred to at any time.

[0236] If the thickness of the pre-drying treatment liquid film 120 before the precipitation of the solid 121 of the sublimable substance is the same, the thickness of the solid 121 of the sublimable substance increases with the increase in the concentration of the sublimable substance and decreases with the decrease in the concentration of the sublimable 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 121 of the sublimable substance can be estimated before the precipitation of the solid 121 of the sublimable substance.

[0237] Fig.15 is a flowchart showing the first example process of the film thickness monitoring process. Hereinafter, refer to Figure 2 and Fig.15 . The film thickness monitoring process is executed, for example, together with the first precipitation process (step S7) at the beginning (refer to Fig. 9 ). That is, the film thickness monitoring process is performed only when the solid 121 of the sublimable substance is precipitated for the first time.

[0238] When starting to measure the thickness of the pre-drying treatment liquid film 120, the controller 3 determines whether the first precipitation process (precipitation process) at the beginning has started ( Fig.15 , step S21). The determination of whether the first precipitation process at the beginning has started is made, for example, based on whether the pre-drying treatment liquid valve 41 is opened, that is, whether the spraying of the pre-drying treatment liquid has stopped.

[0239] When the first precipitation process has not started (in Fig.15 , step S21, the answer is no), that is, when the spraying of the pre-drying treatment liquid has stopped, the controller 3 determines whether the first precipitation process has started after a predetermined time ( Fig.15Step S21). If the first precipitation process has started (in Fig.15 Step S21, the answer is yes), that is, if the spraying of the pre-drying treatment liquid has stopped, the controller 3 causes the film thickness measurement unit 91 to start measuring the film thickness of the pre-drying treatment liquid (film thickness measurement process, Fig.15 Step S22).

[0240] During the period when the film thickness measurement unit 91 measures the thickness of the pre-drying treatment liquid film 120, the controller 3 also measures the film thickness reduction rate of the pre-drying treatment liquid film 120 based on the thickness of the pre-drying treatment liquid film 120 (film thickness reduction rate measurement process).

[0241] The reference speed range representing the appropriate film thickness reduction rate range is specified by the processing program based on the reference concentration range representing the concentration of the appropriate sublimable substance in the liquid film of the pre-drying treatment liquid and the reference data SD. Before the concentration of the sublimable substance in the pre-drying treatment liquid film 120 reaches the saturation concentration, the controller 3 determines whether the film thickness reduction rate is appropriate. In other words, it determines whether the film thickness reduction rate is within the reference speed range (reduction rate determination process, Fig.15 Step S23). Accordingly, it is substantially possible to determine whether the concentration of the solid of the sublimable substance in the pre-drying treatment liquid film 120 is within the reference concentration range (concentration determination process).

[0242] When the film thickness reduction rate is appropriate, in other words, when 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 (in Fig.15 Step S23, the answer is yes), the controller 3 determines whether the solid 121 of the sublimable substance precipitates for the first time in the first precipitation process ( Fig. 9 Step S8) based on the detection value of the film thickness measurement unit 91 ( Fig.15 Step S24). If the solid 121 of the sublimable substance has not precipitated (in Fig.15 Step S24, the answer is no), the controller 3 determines again whether the film thickness reduction rate is appropriate after a predetermined time has elapsed ( Fig.15 Step S23).

[0243] If the solid 121 of the sublimable substance has precipitated (in Fig.15 Step S24, the answer is yes), the controller 3 determines whether the thickness of the solid 121 of the sublimable substance is appropriate based on the measured value of the film thickness measurement unit 91 when the concentration of the sublimable substance in the pre-drying treatment liquid film 120 reaches the saturation concentration immediately before the solid 121 of the sublimable substance is about to precipitate. In other words, the controller 3 determines whether the thickness of the solid 121 of the sublimable substance 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 process, Fig.15Step S25).

[0244] If the thickness of the solid 121 of the sublimable substance is appropriate (in Fig.15 Step S25, it is), the controller 3 causes the film thickness measurement unit 91 to stop measuring the thickness of the pre-treatment liquid film 120 before drying ( Fig.15 Step S26). If the thickness of the solid 121 of the sublimable substance is not appropriate (in Fig.15 Step S25, it is not), the controller 3 causes the alarm device 100C (refer to Figure 8 ) to generate an alarm (second abnormal notification process, Fig.15 Step S27). Thereafter, the measurement of the thickness of the pre-treatment liquid film 120 performed by the film thickness measurement unit 91 is stopped ( Fig.15 Step S26).

[0245] When, due to some reason such as a failure of the first flow rate adjustment valve 107A or the second flow rate adjustment valve 107B (refer to Figure 7 ), the concentration of the sublimable substance is outside the reference concentration range, the film thickness reduction rate is greater than the upper limit value of the reference speed range, or the film thickness reduction rate is less than the lower limit value of the reference speed range (in Fig.15 Step S23, it is not), the controller 3 causes the alarm device 100C (refer to Figure 8 ) to generate an alarm (first abnormal notification process, Fig.15 Step S28).

[0246] Thereafter, the controller 3 starts the pre-treatment liquid removal process before drying and removes the pre-treatment liquid from the upper surface of the substrate W before the solid 121 of the sublimable substance precipitates ( Fig.15 Step S29). The details of the pre-treatment liquid removal process before drying are described below. Then, the controller 3 causes the film thickness measurement unit 91 to stop measuring the film thickness of the pre-treatment liquid ( Fig.15 Step S26).

[0247] When the substrate processing is not interrupted, after performing the first precipitation process ( Fig. 9 Step S7) and the film thickness monitoring process, the first dissolution process is started ( Fig. 9 Step S8). When the pre-treatment liquid before drying is a solution of a sublimable substance and IPA, in order to dissolve the solid 121 of the sublimable substance that has precipitated in the pre-treatment liquid, the substrate W is heated. Then, after repeating the first precipitation process and the first dissolution process a predetermined number of times, the final precipitation process is performed, and finally the sublimation process is performed. In Fig. 9 when N = 0, the first precipitation process and the first dissolution process are not repeated, but the final precipitation process is performed, and finally the sublimation process is performed.

[0248] 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 is completed.

[0249] Fig.16 It is a schematic diagram for explaining an example of the pre-drying treatment liquid removal step in the first example of the film thickness monitoring step.

[0250] As described above, the controller 3 measures the reduction rate of 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 ( Fig.15 step S23). The reason is that if the concentration of the sublimable substance in the pre-drying treatment liquid film 120 is abnormal, that is, if the concentration of the sublimable substance in the pre-drying treatment liquid film 120 is outside the reference concentration range, then in the final precipitation step ( Fig. 9 step S9), the thickness of the solid 121 of the sublimable substance precipitated will be greater than or less than the intended value. If the thickness of the solid 121 of the sublimable substance just before sublimation is greater than or less than the intended value, the collapse rate of the pattern PA may deteriorate.

[0251] Therefore, the controller 3 performs Fig.16 the pre-drying treatment liquid removal step shown ( Fig.15 step S29). Fig.16 It shows a state where the replacement liquid nozzle 43 sprays a solvent equivalent to the replacement liquid onto the upper surface of the substrate W. Fig.16 An example is shown in which the pre-drying treatment liquid is a solution of camphor and IPA, and the solvent is IPA. When the pre-drying treatment liquid is a solution of camphor and methanol, methanol is sprayed from the replacement liquid nozzle 43 instead of IPA.

[0252] When the concentration of the sublimable substance in the pre-drying treatment liquid film 120 is abnormal, as Fig.16 shown, the controller 3 can also cause the replacement liquid nozzle 43 to spray a solvent. In this case, the pre-drying treatment liquid on the substrate W is replaced with a solvent, and a liquid film of the solvent covering the entire upper surface area of the substrate W is formed. Therefore, it is possible to remove the pre-drying treatment liquid with an inappropriate concentration of the sublimable substance from the substrate W before the solid 121 of the sublimable substance precipitates. 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 not within the reference concentration range, the pre-drying treatment liquid removal step is performed, and by supplying the solvent as the removal liquid to the upper surface of the substrate W before the solid 121 of the sublimable substance precipitates in the first precipitation step, the pre-drying treatment liquid is removed from the upper surface of the substrate W.

[0253] Thus, when the pre-drying treatment liquid is a solution of camphor and IPA, in the pre-drying treatment liquid removal process, IPA functions as a removal liquid for removing the pre-drying treatment liquid from the upper surface of the substrate W. When the pre-drying treatment liquid is a solution of camphor and methanol, in the pre-drying treatment liquid removal process, methanol functions as a removal liquid. The removal liquid is preferably a liquid of the same type as the solvent used in the pre-drying treatment liquid, but is not limited thereto. As long as the removal liquid is compatible with the pre-drying treatment liquid, it may also be a liquid of a different type from the solvent of the pre-drying treatment liquid.

[0254] After the controller 3 interrupts the first precipitation process and starts the pre-drying treatment liquid removal process ( Fig.15 step S29), the controller 3 stops the measurement of the thickness of the pre-drying treatment liquid film 120 by the film thickness measurement unit 91 ( Fig.15 step S26).

[0255] In the substrate treatment of the present embodiment, when the solid 121 of the sublimable substance starts to precipitate in the first precipitation process, the pre-drying treatment liquid remains on the upper surface of the substrate W. In the first dissolution process, at least a part of the solid 121 of the sublimable substance is dissolved in the pre-drying treatment liquid. Thereafter, in the final precipitation process, the solvent is evaporated from the pre-drying treatment liquid again. Accordingly, the content of the solvent decreases, and the solid 121 of the sublimable substance precipitates on the upper surface of the substrate W. Thereafter, the solid 121 of the sublimable substance is sublimated and removed from the substrate W. In this way, the pre-drying treatment liquid is removed from the substrate W, and the substrate W is dried.

[0256] Before the solid 121 of the sublimable substance is first precipitated, the pre-drying treatment liquid exists not only between the patterns PA but also above the patterns PA. In a substrate W such as a semiconductor wafer or a substrate for an FPD, the interval G1 between the patterns PA is narrow. When the interval G1 between the patterns PA is narrow, the property of the pre-drying treatment liquid existing between the patterns PA is different from that of the main body of the pre-drying treatment liquid, that is, the pre-drying treatment liquid in the range from the surface (upper surface) of the pre-drying treatment liquid film 120 to the upper surface of the patterns PA. The difference in the properties between the two becomes significant as the interval G1 between the patterns PA becomes narrower.

[0257] If the interval G1 of the pattern PA is narrow, the following situation exists: when the solid 121 of the sublimable substance first precipitates, the solid 121 of the sublimable substance only precipitates in the main body of the pre-drying treatment liquid, and an incomplete precipitation region where the solid 121 of the sublimable substance does not exist or hardly exists between the patterns PA is formed on the upper surface of the substrate W. In this case, the surface tension of the pre-drying treatment liquid between the patterns PA acts on the side surfaces of the patterns PA. Therefore, when the solid 121 of the sublimable substance sublimes, the patterns PA in the incomplete precipitation region may collapse. This becomes a cause for increasing (deteriorating) the collapse rate of the patterns PA.

[0258] In contrast, if the solid 121 of the precipitated sublimable substance is dissolved in the pre-drying treatment liquid and then the solid 121 of the sublimable substance is precipitated again, crystal nuclei of the solid 121 of the sublimable substance are also formed in a narrow space such as the space between the patterns PA. Therefore, as long as the solid 121 of the precipitated sublimable substance is dissolved in the pre-drying treatment liquid and then the solid 121 of the sublimable substance is precipitated again, even when the interval G1 of the pattern PA is narrow, the generation of the incomplete precipitation region can be prevented or its area can be reduced. Accordingly, the collapse rate of the pattern PA can be reduced.

[0259] The thickness of the solid 121 of the sublimable substance is substantially the same as the thickness of the pre-drying treatment liquid film 120 when the saturation concentration of the sublimable substance is reached. If the concentration of the sublimable substance in the pre-drying treatment liquid film 120 reaches the saturation concentration of the sublimable substance, the solid 121 of the sublimable substance precipitates immediately thereafter. Therefore, as long as 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 of the sublimable substance can be predicted, and the formation of the solid 121 of the sublimable substance with an inappropriate thickness can be avoided.

[0260] Generally, in order to measure the concentration of a substance in a liquid, it is necessary to bring an instrument (not shown) for concentration measurement 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 bring the instrument for concentration measurement into contact with the pre-drying treatment liquid film 120 without contacting the upper surface of the substrate W. Therefore, there is a risk of damaging the pattern PA formed on the upper surface of the substrate.

[0261] As described above, the inventors of the present application 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, before the solid 121 of the sublimable substance precipitates in the first precipitation step at the beginning, based on the film thickness reduction rate of the pre-drying treatment liquid film 120, it is determined whether the concentration of the sublimable substance in the pre-drying treatment liquid film 120 is within the reference concentration range (concentration determination step).

[0262] Specifically, by continuously measuring the thickness of the pre-drying treatment liquid film 120 with the film thickness measurement unit 91 for a predetermined time, the reduction rate of the thickness of the pre-drying treatment liquid film 120 in the first precipitation process can be measured. Therefore, the controller 3 can substantially determine whether the concentration of the sublimable substance in the pre-drying treatment liquid film 120 is within the reference concentration range by determining whether the reduction rate of the film thickness measured by the film thickness measurement unit 91 is within the reference speed range. Accordingly, it is possible to determine whether the concentration of the sublimable substance in the pre-drying treatment liquid film 120 is within the reference concentration range while avoiding difficult measurements.

[0263] Since the amount of the solvent evaporated in the first dissolution process and the final precipitation process is predictable, even when the concentration determination process is performed in the first precipitation process, it is possible to determine whether the thickness of the solid 121 of the sublimable substance formed on the upper surface of the substrate W is appropriate based on the concentration of the sublimable substance in the pre-drying treatment liquid film 120 in the first precipitation process.

[0264] 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, after the final precipitation process, a solid 121 of the sublimable substance with an appropriate thickness is formed. Therefore, as long as the substrate treatment is continued to sublime the solid 121 of the sublimable substance, the overturning rate of the pattern PA on the upper surface of the substrate W can be reduced.

[0265] 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, before the solid 121 of the sublimable substance precipitates, the sublimable substance can be removed from the upper surface of the substrate W by the removal liquid (pre-drying treatment liquid removal process). Accordingly, the situation where a solid 121 of the sublimable substance with an inappropriate thickness is formed on the upper surface of the substrate W can be prevented. Accordingly, an increase in the overturning rate of the pattern PA can be suppressed. In addition, even 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 pre-drying treatment liquid on the upper surface of the substrate W can also be removed. Therefore, the substrate W can be reused.

[0266] In addition, in the present embodiment, by comparing the reference data SD with the reduction rate of the film thickness measured in the first precipitation process, the concentration of the sublimable substance in the pre-drying treatment liquid film 120 is estimated. Therefore, in the first precipitation process, the concentration of the sublimable substance in the pre-drying treatment liquid film 120 can be easily estimated.

[0267] In addition, in the present embodiment, 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 not within the reference concentration range, an abnormality is notified to the operator (first abnormality notification step). Therefore, based on the notification of the abnormality, the operator can determine whether to continue the substrate treatment at an appropriate timing.

[0268] In addition, in the present embodiment, before the solid 121 of the sublimable substance is about to precipitate due to the evaporation of the solvent, the thickness of the pre-drying treatment liquid film 120 is measured by the film thickness measurement unit 91 (film thickness measurement step). Then, the controller 3 determines whether the thickness of the pre-drying treatment liquid film 120 measured in the film thickness measurement step is within the reference thickness range of the solid 121 of the sublimable substance (thickness determination step).

[0269] Therefore, by determining whether the thickness of the pre-drying treatment liquid film 120 when the concentration of the sublimable substance in the pre-drying treatment liquid film 120 reaches the saturation concentration of the sublimable substance is within the reference thickness range of the solid 121 of the sublimable substance, it is possible to determine whether the thickness of the solid 121 of the sublimable substance formed on the upper surface of the substrate W is appropriate.

[0270] When the thickness of the solid 121 of the sublimable substance formed on the upper surface of the substrate W is appropriate, after the final precipitation step is completed, the solid 121 of the sublimable substance with an appropriate thickness is formed. Therefore, as long as the substrate treatment is continued to sublime the solid 121 of the sublimable substance, it is possible to obtain the substrate W with a reduced pattern collapse rate of the pattern PA.

[0271] On the other hand, when the thickness of the solid 121 of the sublimable substance formed on the upper surface of the substrate W is not appropriate, by interrupting the substrate treatment, it is possible to suppress the generation of the substrate W with an increased pattern collapse rate of the pattern PA.

[0272] In the present embodiment, when it is determined in the thickness determination step that the film thickness measured in the film thickness measurement step is not within the reference thickness range, an abnormality is notified to the operator (second abnormality notification step). Therefore, based on the notification of the abnormality, the operator can determine whether to continue the substrate treatment at an appropriate timing.

[0273] 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, the solvent is evaporated from the pre-drying treatment liquid while maintaining the temperature of the pre-drying treatment liquid below room temperature. In this case, on the surface of the pre-drying treatment liquid, the concentration of the sublimable substance locally increases, and the 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 pre-drying treatment liquid remains between the solid 121 of the sublimable substance and the upper surface of the pattern PA. The solid 121 of the sublimable substance dissolves in this pre-drying treatment liquid.

[0274] In contrast, if the solvent is evaporated from the pre-drying treatment liquid by heating the pre-drying treatment liquid in the first precipitation step, the temperature of the pre-drying treatment liquid rises to a value higher than room temperature, and the concentration of the sublimable substance in the pre-drying treatment liquid increases. If, after increasing the concentration of the sublimable substance, the solid 121 of the sublimable substance is precipitated by natural cooling or forced cooling of the pre-drying treatment liquid, there is a case where most or all of the main body of the pre-drying treatment liquid becomes the solid 121 of the sublimable substance.

[0275] If the pre-drying treatment liquid does not remain above the pattern PA, the solid 121 of the sublimable substance will not effectively dissolve in the pre-drying treatment liquid. Even if the pre-drying treatment liquid remains between the patterns PA, the efficiency of the solid 121 of the sublimable substance dissolving in the pre-drying treatment liquid between the patterns PA is inferior to the efficiency of the solid 121 of the sublimable substance dissolving in the main body of the pre-drying treatment liquid. Therefore, by maintaining a part of the main body of the pre-drying treatment liquid as a liquid, the solid 121 of the sublimable substance can be effectively dissolved in the pre-drying treatment liquid.

[0276] In addition, in the present embodiment, in the first dissolution 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 solid 121 of the sublimable substance in the pre-drying treatment liquid is promoted by the rise in the temperature of the pre-drying treatment liquid. Accordingly, the solid 121 of the sublimable substance can be effectively dissolved in the pre-drying treatment liquid. Further, since the forced dissolution of the solid 121 of the sublimable substance starts with the start of heating, the forced dissolution of the solid 121 of the sublimable substance can be started at an arbitrary time by changing the timing of starting the heating.

[0277] In addition, in the present embodiment, in the first dissolution process, the solid 121 of the sublimable substance and the pre-drying treatment liquid are not directly heated from the top of the substrate W, but are indirectly heated across the substrate W (indirect heating process). If the solid 121 of the sublimable substance and the pre-drying treatment liquid are heated from the top of the substrate W, there is a situation where a part of the solid 121 of the sublimable substance located on the surface of the pre-drying treatment liquid sublimates. In this case, a part of the sublimable substance is wasted, and the thickness of the final solid 121 of the sublimable substance is less than the intended value. If the solid 121 of the sublimable substance and the pre-drying treatment liquid are heated across the substrate W, can the disappearance of such sublimable substance be reduced.

[0278] In addition, in the present embodiment, in the final precipitation process, in order to precipitate the solid 121 of the sublimable substance on the substrate W, the pre-drying treatment liquid is heated while the solvent is evaporated from the pre-drying treatment liquid. Accordingly, the solid 121 of the sublimable substance is precipitated from the high-temperature pre-drying treatment liquid. The saturation concentration of the sublimable substance in the pre-drying treatment liquid increases as the temperature of the pre-drying treatment liquid increases. The ratio of the solvent contained in the solid 121 of the sublimable substance 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 may generate a destructive force that destroys the pattern PA. Therefore, by reducing the content of the solvent, the destructive rate of the pattern PA can be further reduced.

[0279] In addition, in the present embodiment, in the 1st precipitation process, the solid 121 of sublimable substance is precipitated on the surface of the dry pre-treatment liquid film 120 (liquid surface precipitation process). When the solvent evaporates from the dry pre-treatment liquid, the heat of the dry pre-treatment liquid equivalent to the heat of vaporization is released in the gas atmosphere together with the solvent, and the temperature of the surface of the dry pre-treatment liquid is reduced. When the solid 121 of sublimable substance is formed, the solvent evaporated from the dry pre-treatment liquid is reduced, and therefore, the heat of the dry pre-treatment liquid released in the gas atmosphere is also reduced. Meanwhile, the heat in the gas atmosphere is transferred to the dry pre-treatment liquid via the solid 121 of sublimable substance. Accordingly, the temperature of the interface of the solid 121 of sublimable substance and the dry pre-treatment liquid rises. Therefore, even if the dry pre-treatment liquid on the substrate W is not heated compulsorily, the solid 121 of sublimable substance can be dissolved in the dry pre-treatment liquid (natural dissolution process).

[0280] The film thickness monitoring process is not limited to Fig.15 For example, Fig.17 A flowchart showing the flow of the second example of the film thickness monitoring process is shown in FIG. Fig. 20 A flowchart showing the flow of the third example of the film thickness monitoring process is shown in FIG. Fig. 22The flowchart showing the fourth example of the film thickness monitoring process is shown.

[0281] In Fig.17 the film thickness monitoring process of the second example shown, the aspect different from the film thickness monitoring process of the first example (refer to Fig.15 ) is as follows: 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, and when 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, different processes are started.

[0282] In the film thickness monitoring process of the second example, when the film thickness reduction rate is greater than the upper limit value of the reference speed range or the film thickness reduction rate is less than the lower limit value of the reference speed range (in Fig.17 step S23, the answer is no), the controller 3 causes the alarm device 100C (refer to Figure 8 ) to generate an alarm (the first abnormal notification process, Fig.17 step S28). Thereafter, the controller 3 determines whether the film thickness reduction rate is less than the lower limit value of the reference speed range ( Fig.17 step S31).

[0283] When the film thickness reduction rate is less than the lower limit value of the reference speed range (in Fig.17 step S31, the answer is yes), that is, 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 controller 3 starts the solvent evaporation inhibition process to inhibit the evaporation of the solvent from the liquid film on the substrate W ( Fig.17 step S32). Accordingly, the concentration of the sublimable substance in the pre-drying treatment liquid film 120 is reduced and adjusted within the reference concentration range.

[0284] On the other hand, when the film thickness reduction rate is greater than the upper limit value of the reference speed range (in Fig.17 step S31, the answer is no), that is, when 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 controller 3 starts the solvent evaporation promotion process to promote the evaporation of the solvent from the pre-drying treatment liquid film 120 ( Fig.17 step S33). Accordingly, the concentration of the sublimable substance in the pre-drying treatment liquid film 120 is increased and adjusted within the reference concentration range.

[0285] After starting the solvent evaporation inhibition process or the solvent evaporation promotion process, similar to the first example of the film thickness monitoring process shown in Fig.15 , the controller 3 stops the measurement of the thickness of the pre-drying treatment liquid film 120 by the film thickness measurement unit 91 ( Fig.17 step S26).

[0286] Fig.18 This is a schematic diagram for explaining an example of a solvent evaporation suppression process. In the solvent evaporation suppression process, for example, the 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. Fig.18 An example is shown in which the pre-drying treatment 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 the mist or vapor of IPA. When the pre-drying treatment liquid is a solution of camphor and methanol, nitrogen gas containing the mist or vapor of methanol is ejected onto the upper surface of the substrate W. Nitrogen gas serves as a carrier gas for transporting the mist or vapor of the solvent to the substrate W.

[0287] When ejecting into the space between the upper surface of the substrate W and the lower surface 51L of the blocking member 51, it is sufficient to supply nitrogen gas to the IPA (liquid) in the tank (so-called bubbling). In this way, a plurality of nitrogen gas bubbles are formed in the IPA, and the nitrogen gas containing the mist or vapor of IPA is released from the surface of the IPA in the tank. It is sufficient to eject this nitrogen gas from at least one of the central nozzle 55 and the upper central opening 61 of the blocking member 51.

[0288] If the 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 vapor pressure of the solvent in the gas atmosphere in contact with the pre-drying treatment liquid film 120 increases. Therefore, the 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 gas atmosphere remains unchanged, although it is a small amount, the sublimable substance evaporates from the pre-drying treatment liquid. Therefore, assuming that the concentration of the sublimable substance is higher than the upper limit value of the reference concentration range, as long as the 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 to a concentration within the reference concentration range, and the solid 121 of the sublimable substance with the intended thickness can be precipitated.

[0289] Fig.19 This is a schematic diagram for explaining an example of a solvent evaporation promotion process. In the solvent evaporation promotion process, for example, a gas such as nitrogen gas that does not contain the mist or vapor of IPA 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 can cause the central nozzle 55 to eject nitrogen gas, or can cause the upper central opening 61 of the blocking member 51 to eject nitrogen gas. When the central nozzle 55 has ejected nitrogen gas, the controller 3 can also increase the opening degree of the flow rate adjustment valve 58 (refer to Figure 2 )). When the upper central opening 61 of the blocking member 51 has ejected nitrogen gas, the controller 3 can also increase the opening degree of the flow rate adjustment valve 65 (refer to Figure 2 ).

[0290] If nitrogen is supplied to the space between the upper surface of substrate W and the lower surface 51L of blocking member 51, the vapor pressure of the solvent in the gas atmosphere contacted with the dry pre-treatment liquid film 120 is reduced. Therefore, the solvent is promoted to evaporate from the dry pre-treatment liquid. Strictly speaking, the vapor pressure of the sublimation substance in the gas atmosphere is also a trace, but it reduces. However, because the vapor pressure of the sublimation substance is much smaller than the vapor pressure of the solvent, the solvent mainly evaporates from the dry pre-treatment liquid. Therefore, the concentration of the sublimation substance in the dry pre-treatment liquid film 120 can be set to the concentration within the reference concentration range, and the solid 121 of the sublimation substance of the intended thickness can be separated out.

[0291] The nitrogen gas ejected from the central nozzle 55 and the upper central opening 61 of the blocking member 51 promotes the precipitation of the solid 121 of the sublimable substance, so that the central nozzle 55 and the upper central opening 61 of the blocking member 51 function as a solvent evaporating unit.

[0292] By comparing the film thickness reduction rate immediately before the solvent evaporation suppression process or the solvent evaporation promotion process is performed with the film thickness reduction rate included in the reference data SD, it is possible to calculate the appropriate amount of evaporation of the solvent from the pre-drying treatment liquid film 120 in order to set the concentration of the sublimable substance in the pre-drying treatment liquid film 120 to a concentration within the reference concentration range. As long as the solvent evaporation suppression process or the solvent evaporation promotion process is performed in a manner such that the evaporation amount of the solvent becomes an appropriate evaporation amount, the thickness of the pre-drying treatment liquid film 120 when the concentration of the sublimable substance reaches the saturation concentration can be easily adjusted to an appropriate thickness. In addition, the solid 121 of the sublimable substance of an appropriate thickness can be precipitated.

[0293] 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 evaporation of the solvent from the pre-drying treatment liquid film 120 is suppressed by supplying solvent vapor or mist to the gas atmosphere in contact with the pre-drying treatment liquid film 120 (solvent evaporation suppression process).

[0294] By supplying the vapor or mist of the solvent to the gas atmosphere in contact with the pre-drying treatment liquid film 120, the amount of the solvent (the vapor pressure of the solvent) present in the gas atmosphere in contact with the pre-drying treatment liquid film 120 increases. Accordingly, the evaporation of the solvent from the pre-drying treatment liquid film 120 can be suppressed. If the evaporation of the solvent from the pre-drying treatment liquid film 120 is suppressed, the ratio of the sublimable substance in the substance 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. Accordingly, the concentration of the sublimable substance in the pre-drying treatment liquid film 120 can be adjusted to within the reference concentration range.

[0295] 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, since the solvent evaporation suppression step is performed, after the sublimation step, a substrate W with a reduced overturning rate of the pattern PA can be obtained.

[0296] In addition, in the second example of the film thickness monitoring step, 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 lower than the lower limit value of the reference concentration range, by supplying an inert gas to the gas atmosphere in contact with the pre-drying treatment liquid film 120 during the execution of the first precipitation step, the evaporation of the solvent from the pre-drying treatment liquid film 120 is promoted (solvent evaporation promotion step).

[0297] By promoting the evaporation of the solvent from the pre-drying treatment liquid film 120, the concentration of the sublimable substance in the pre-drying treatment liquid film 120 increases. Accordingly, 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, since the solvent evaporation promotion step is performed, after the sublimation step, a substrate W with a reduced overturning rate of the pattern PA can be obtained.

[0298] In Fig. 20 In the third example of the film thickness monitoring step shown, the aspect different from the second example of the film thickness monitoring step (refer to Fig.17 ) is as follows: When the film thickness reduction rate is less than the lower limit value of the reference speed range (in Fig. 20 , in step S31, it is yes), that is, 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 controller 3 starts the thinning process to thin the pre-drying treatment liquid film 120 on the substrate W ( Fig. 20 , step S34).

[0299] When the film thickness reduction rate is greater than the upper limit value of the reference speed range (in Fig. 20 , in step S31, it is no), that is, when 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, similar to the second example of the film thickness monitoring step, the controller 3 starts the solvent evaporation promotion step ( Fig. 20 , step S33).

[0300] In the thinning process, the controller 3 accelerates the rotation of the substrate W by the rotation motor 14. Accordingly, the centrifugal force acting on the pre-drying treatment liquid film 120 on the substrate W increases, and the amount of the pre-drying treatment liquid discharged outside the substrate W increases.

[0301] Fig.21A and Fig. 21B are schematic diagrams for explaining the thin film forming process. Fig.21A represents the state before accelerating the rotation of the substrate W, Fig. 21B represents the state after accelerating the rotation of the substrate W. Specifically, the rotation speed of the substrate W is changed from the first deposition speed (e.g., 500 rpm) to a higher thin film forming speed (e.g., 1500 rpm) than the first deposition speed.

[0302] 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 thickness of the solid 121 of the sublimable substance just before sublimation is greater than the intended value. If the thickness of the pre-drying treatment liquid film 120 on the substrate W is reduced, the amount of the sublimable substance contained in the pre-drying treatment liquid film 120 is reduced, and thus the thickness of the solid 121 of the sublimable substance is also reduced.

[0303] 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, by increasing the rotation speed of the substrate W, centrifugal force acts on the pre-drying treatment liquid film 120, thereby reducing the thickness of the pre-drying treatment liquid film 120 before the solid 121 of the sublimable substance is deposited. Accordingly, the thickness of the solid 121 of the sublimable substance formed on the upper surface of the substrate W can be reduced, and the solid 121 of the sublimable substance with the intended thickness can be deposited. Therefore, even if 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, since the thin film forming process is performed, after the sublimation process, a substrate W with a reduced pattern PA collapse rate can be obtained.

[0304] When the pre-drying treatment liquid is a solution of camphor and IPA, the fourth example of the film thickness monitoring process shown in Fig. 22 can also be performed. The fourth example of the film thickness monitoring process is different from the first example of the film thickness monitoring process (refer to Fig.15 ) in the following aspect: When it is determined that the thickness of the solid 121 of the sublimable substance is within the reference thickness range (in Fig. 22 , in step S25, it is yes), the controller 3 starts the first dissolution process ( Fig. 22 , step S45). That is, the controller 3 starts to supply a heating liquid such as warm water to the lower surface of the substrate W and starts to heat the liquid film of the pre-drying treatment liquid on the upper surface of the substrate W through the substrate W. Thereafter, the film thickness measurement unit 91 is made to stop measuring the film thickness of the pre-drying treatment liquid ( Fig. 22 , step S26).

[0305] In the fourth example of the film thickness monitoring process, the first dissolution process starts on the occasion of forming the solid 121 of the sublimable substance with an appropriate thickness. Therefore, only when the solid 121 of the sublimable substance with an appropriate thickness is formed, the first dissolution process, the final precipitation process, and the sublimation process are executed. After the sublimation process is completed, a substrate W with a reduced collapse rate of the pattern PA can be obtained. When the solid 121 of the sublimable substance with an appropriate thickness is not formed, the processes after the first precipitation process (the first dissolution process, the final precipitation process, and the sublimation process) can be not executed, and the substrate processing can be interrupted early.

[0306] When the time from the precipitation of the solid 121 of the sublimable substance to sublimation is short, before dissolving the solid 121 of the sublimable substance in the pre-drying treatment liquid, in other words, before starting the heating of the pre-drying treatment liquid, part or all of the solid 121 of the sublimable substance may sublime. In such a case, as long as it is monitored whether the solid 121 of the sublimable substance is precipitated, the heating of the pre-drying treatment liquid can be started at the best timing, and the solid 121 of the sublimable substance that sublimates unintentionally can be reduced.

[0307] The present invention is not limited to the content of the above-described embodiment, and various modifications can be made.

[0308] As described above, in the above substrate processing, the film thickness monitoring process is executed together with the first precipitation process (step S7) at the beginning. However, when the pre-drying treatment liquid is a solution of camphor and IPA, the monitoring of the thickness of the pre-drying treatment liquid film can also be performed whenever the solid 121 of the sublimable substance is precipitated.

[0309] In addition, when the pre-drying treatment liquid is a solution of camphor and IPA, the monitoring of the thickness of the pre-drying treatment liquid film 120 can also be as Fig. 9 shown by the two-dot chain line, and can be performed together with the final precipitation process ( Fig. 9 step S9). In other words, when the pre-drying treatment liquid is a solution of camphor and IPA, as long as the thickness of the pre-drying treatment liquid film 120 is monitored in parallel with at least one of the first precipitation process ( Fig. 9 step S7) and the final precipitation process ( Fig. 9 step S9).

[0310] Different from the substrate processing of the above-described embodiment (refer to Fig. 9 ), as Fig.23 shown, it is also possible to execute substrate processing in which the solid 121 of the sublimable substance precipitated in the pre-drying treatment liquid film 120 is not dissolved in the pre-drying treatment liquid but sublimated.

[0311] In Fig.23In the substrate processing, after the film thickness reduction step (step S6), a deposition step (step S50) is performed to deposit the solid of the sublimable substance on the upper surface of the substrate W, and then a sublimation step (step S10) is performed. Then, any one of the film thickness monitoring steps in the first to third examples is performed in parallel with the deposition step (step S50).

[0312] In the first deposition step ( Fig. 9 step S7) where the solid 121 of the sublimable substance is deposited for the first time, instead of maintaining the pre-treatment liquid film 120 before drying at a temperature below room temperature, the solvent may be evaporated from the pre-treatment liquid on the substrate W while heating at a heating temperature higher than room temperature.

[0313] In the final deposition step ( Fig. 9 step S9) of the first substrate processing example, instead of heating the pre-treatment liquid on the substrate W while evaporating the solvent from the pre-treatment liquid, the solvent may be evaporated from the pre-treatment liquid while stopping the forced heating of the pre-treatment liquid on the substrate W.

[0314] When dissolving the solid 121 of the sublimable substance in the pre-treatment liquid, instead of supplying warm water, which is an example of a heating liquid with a temperature higher than room temperature, to the lower surface of the substrate W, a heating gas with a temperature higher than room temperature may be ejected onto the upper surface or the lower surface of the substrate W. For example, at least one of the central nozzle 55 and the lower central opening 81 of the rotating base 12 may eject nitrogen with a temperature higher than room temperature. A heating element that generates Joule heat by energization or a lamp that emits light to the substrate W may be arranged above and / or below the substrate W. For example, the heating element may be built into at least one of the rotating base 12 and the shielding member 51.

[0315] The solid 121 of the sublimable substance may also be removed by a processing unit 2 different from the wet processing unit 2w. The processing unit 2 for removing the solid 121 of the sublimable substance may be a part of the substrate processing apparatus 1 or a part of a substrate processing apparatus 1 different from the substrate processing apparatus 1. In other words, the substrate processing apparatus 1 equipped with the wet processing unit 2w and the substrate processing apparatus 1 equipped with the processing unit 2 for removing the solid 121 of the sublimable substance may be provided in the same substrate processing system, and the substrate W may be transported from the substrate processing apparatus 1 to another substrate processing apparatus 1 before removing the solid 121 of the sublimable substance.

[0316] When it is possible to replace the rinsing liquid on the substrate W, such as pure water, with the pre-treatment liquid before drying, instead of performing a replacement liquid supply step of replacing the rinsing liquid on the substrate W with a replacement liquid, a pre-treatment liquid supply step may be performed.

[0317] In addition to the disc portion 52, the blocking member 51 may also include a cylindrical portion extending downward from the outer peripheral portion of the disc portion 52. In this case, when the blocking member 51 is disposed at the lower position, the substrate W held by the rotary chuck 10 is surrounded by the cylindrical portion 25.

[0318] The blocking member 51 may also rotate together with the rotary chuck 10 about the rotation axis A1. For example, the blocking member 51 may be placed on the rotary base 12 so as not to contact the substrate W. In this case, since the blocking member 51 is connected to the rotary base 12, the blocking member 51 rotates in the same direction and at the same speed as the rotary base 12.

[0319] The blocking member 51 may be omitted. However, when a liquid such as pure water is supplied to the lower surface of the substrate W, it is preferable to provide the blocking member 51. The reason is that the blocking member 51 can block the droplets flowing back from the lower surface of the substrate W to the upper surface of the substrate W along the outer peripheral surface of the substrate W and the droplets splashing inward from the processing cup 21, and can reduce the liquid mixed into the pre-drying processing liquid on the substrate W.

[0320] If it is not necessary to change the incident position of the light of the light-emitting element 92 with respect to the upper surface of the substrate W, the electric motor 96 of the film thickness measuring unit 91 may be omitted.

[0321] When the light of the light-emitting element 92 is incident on the upper surface of the substrate W substantially vertically, the housing 93 of the film thickness measuring 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 covered by the transparent plate 94 and is received by the light receiving element 97 inside the housing 93.

[0322] When both the light-emitting element 92 and the light receiving element 97 are accommodated in the housing 93, the controller 3 may also move the housing 93 horizontally so that the incident position of the light of the light-emitting element 92 on the upper surface of the substrate W moves in the radial direction of the substrate W. Specifically, a scanning arm that holds the housing 93 above the substrate W held by the rotary chuck 10 and an electric drive that horizontally moves the scanning arm in the chamber 4 may be provided in the processing unit 2.

[0323] In the above-described embodiment, the film thickness measuring unit 91 cannot measure the liquid film of the pre-drying processing liquid after the solid 121 of the sublimable substance is deposited. Different from the above-described embodiment, a film thickness measuring unit 191 capable of measuring the thickness of the solid 121 of the sublimable substance may be used as the film thickness measuring unit (see Fig.25A)。The film thickness measurement unit 191 houses the light-emitting element 191A and the light-receiving element 191B in the same housing 191C. The film thickness measurement unit 191 can move along the radial direction of rotation of the substrate W, for example, by the moving unit 192. Specifically, a scanning arm that holds the housing 191C above the substrate W held by the rotary chuck 10 and an electric drive that horizontally moves the scanning arm in the chamber 4 may be provided in the processing unit 2.

[0324] Therefore, the film thickness measurement unit 191 can measure the thickness of the solid 121 (solid film) of the sublimable substance deposited on the upper surface of the substrate W at multiple positions on the upper surface of the substrate W while moving above the substrate W. Fig.25A The multiple black dots Pi in represent the incident positions where the light from the light-emitting element 191A enters the upper surface of the substrate W.

[0325] As long as the film thickness measurement unit 191 is configured to be able to measure at multiple positions on the upper surface of the substrate W, the fifth example of the film thickness monitoring process shown in Fig.24 can be executed. Fig.24 The fifth example of the film thickness monitoring process shown in is different from the first example of the film thickness monitoring process shown in Fig.15 in the following aspects: a flatness measurement process is performed to measure the flatness of the surface of the solid 121 of the sublimable substance on the upper surface of the substrate W; and a flatness determination process is performed to determine whether the surface of the solid 121 of the sublimable substance is flat.

[0326] Specifically, when the thickness of the solid 121 of the sublimable substance is appropriate (in Fig.24 step S25, it is "yes"), the movement of the film thickness measurement unit 191 in the radial direction of rotation of the substrate W is started ( Fig.24 step S51). Accordingly, as shown in Fig.25A , the flatness of the surface of the solid 121 of the sublimable substance is measured (flatness measurement process).

[0327] The flatness refers to, for example, the degree of unevenness of the height positions of the surface of the solid 121 of the sublimable substance measured at multiple positions. The height position of the surface of the solid 121 of the sublimable substance can be directly measured by the film thickness measurement unit 191 for the height position of the surface of the solid 121 of the sublimable substance, or can be calculated from the thickness of the solid 121 of the sublimable substance measured by the film thickness measurement unit 191. The smaller the unevenness of the height positions of the surface of the solid 121 of the sublimable substance measured at multiple positions, the flatter the surface of the solid 121 of the sublimable substance.

[0328] And it is determined whether the surface of the solid 121 of the sublimable substance is flat enough (flatness determination process, Fig.24Step S52). Accordingly, it is possible to check whether the solid 121 of the sublimable substance with a uniform thickness is formed over the entire area of the upper surface of the substrate W.

[0329] Specifically, when the flatness measured in the flatness measurement step is within the reference flatness range (in Fig.24 Step S52, it is "yes"), that is, when the surface of the solid 121 of the sublimable substance is sufficiently flat, the measurement of the thickness of the pre-drying treatment liquid film 120 performed by the film thickness measurement unit 191 is stopped ( Fig.24 Step S26). Thereafter, as usual, the sublimation step ( Fig. 9 Step S10) is performed. Thus, it is possible to obtain the substrate W with a reduced pattern PA collapse rate.

[0330] When the flatness measured in the flatness measurement step is not within the reference flatness range (in Fig.24 Step S52, it is "no"), that is, when the surface of the solid 121 of the sublimable substance is not flat enough, the solid 121 of the sublimable substance is removed from the upper surface of the substrate W (solid removal step, Fig.24 Step S53). In the solid removal step, as Fig.25B shown, a solvent equivalent to the replacement liquid is supplied from the replacement liquid nozzle 43 to the upper surface of the substrate W on which the solid 121 of the sublimable substance is formed.

[0331] Fig.25B An example is shown in which the pre-drying treatment liquid is a solution of camphor and IPA, and the solvent is IPA. When the pre-drying treatment liquid is a solution of camphor and methanol, methanol is ejected from the replacement liquid nozzle 43 instead of IPA. Accordingly, as Fig.25C shown, the solid 121 of the sublimable substance is removed. Thereafter, the measurement of the thickness of the pre-drying treatment liquid film 120 performed by the film thickness measurement unit 191 is stopped ( Fig.24 Step S26).

[0332] In the film thickness monitoring step of the fifth example, the solid removal step is performed. Therefore, even when there are parts with too thin or too thick thickness in a part of the solid 121 of the sublimable substance, it is possible to suppress the collapse of the pattern PA. In addition, since the solid 121 of the sublimable substance on the upper surface of the substrate W is removed, the substrate W can be reused.

[0333] Thus, when the pre-drying treatment liquid is a solution of camphor and IPA, in the solid removal step, IPA functions as a solid removal liquid for removing the solid 121 of the sublimable substance from the upper surface of the substrate W. When the pre-drying treatment liquid is a solution of camphor and methanol, in the solid removal step, methanol functions as a solid removal liquid. The solid removal liquid is preferably a liquid of the same type as the solvent used in the pre-drying treatment liquid, but is not limited thereto. As long as the solid removal liquid can remove the solid 121 of the sublimable substance, it may be a liquid of a different type from the solvent of the pre-drying treatment liquid.

[0334] The substrate processing apparatus 1 is disposed in a clean room, and the temperature inside the substrate processing apparatus 1 is maintained at the same or substantially the same value as the temperature in the clean room, but the temperature inside the substrate processing apparatus 1 may also be different from the temperature in the clean room. For example, the substrate processing apparatus 1 may also include an air conditioner for adjusting the temperature inside the substrate processing apparatus 1.

[0335] When the pre-drying treatment liquid is a solution of camphor and methanol, if the temperature inside the substrate processing apparatus 1, more specifically, the temperature inside the chamber 4, is higher than the surface temperature of the pre-drying treatment liquid at the time of sublimable substance precipitation (hereinafter referred to as "precipitation surface temperature"), then when only the pre-drying treatment liquid is placed on the upper surface of the substrate W, the temperature at the interface between the solid 121 of the sublimable substance and the pre-drying treatment liquid rises, and the solid 121 of the sublimable substance dissolves in the pre-drying treatment liquid. Accordingly, the precipitation and dissolution of the sublimable substance are naturally repeated.

[0336] When the temperature in the clean room is lower than the precipitation surface temperature, the controller 3 may also cause the air conditioner to adjust the temperature inside the substrate processing apparatus 1 so that the internal space of the chamber 4 is maintained at a temperature higher than the precipitation surface temperature. Similarly, when the air pressure in the clean room is a value unsuitable for the precipitation and dissolution of the sublimable substance, the controller 3 may also change at least one of the output of the FFU 6 (refer to Figure 2 ) and the opening degree of the exhaust valve 9 (refer to Figure 2 ). 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 changes, and the air pressure inside the chamber 4 is maintained at a value suitable for the precipitation and dissolution of the sublimable substance.

[0337] The substrate processing apparatus 1 may also include at least one of a thermometer for measuring the temperature inside the chamber 4 and a barometer for measuring the air pressure inside the chamber 4. During the processing of the substrate W by the processing unit 2, when at least one of the temperature and air pressure inside the chamber 4 changes significantly, the controller 3 may also stop the next substrate W from being transferred into the chamber 4 until both the temperature and air pressure inside the chamber 4 are maintained at values suitable for the precipitation and dissolution of the sublimable substance.

[0338] The substrate processing apparatus 1 is not limited to an apparatus for processing a disk-shaped substrate W, and may also be an apparatus for processing a polygonal substrate W.

[0339] The embodiments of the present invention have been described in detail, but these are merely specific examples for clarifying the technical content of the present invention. The present invention should not be construed as being limited to these specific examples, and the scope of the present invention is defined only by the appended claims.

[0340] This application corresponds to Japanese Patent Application No. 2018-248018 filed with the Japan Patent Office on December 28, 2018, and the entire disclosure of this application is incorporated herein by reference.

[0341] Reference Signs

[0342] 1: Substrate processing apparatus

[0343] 3: Controller

[0344] 10: Rotating chuck

[0345] 14: Rotation motor (solvent evaporation unit, sublimation unit)

[0346] 39: Pretreatment liquid nozzle for drying (pretreatment liquid supply unit for drying)

[0347] 55: Central nozzle (solvent evaporation unit, sublimation unit)

[0348] 61: Upper central opening of the blocking member (solvent evaporation unit, sublimation unit)

[0349] 71: Lower surface nozzle (solvent evaporation unit)

[0350] 91: Film thickness measurement unit

[0351] 120: Pretreatment liquid film for drying (liquid film of the pretreatment liquid for drying)

[0352] 121: Solid of the sublimable substance

[0353] 191: Film thickness measurement unit

[0354] PA: Pattern

[0355] W: Substrate.

Claims

1. A substrate processing method, comprising: A pre-drying treatment liquid supply step of supplying a pre-drying treatment liquid, which is a solution obtained by dissolving a sublimable substance in a solvent, to the upper surface of a patterned substrate, and forming a liquid film of the pre-drying treatment liquid on the upper surface of the substrate; A precipitation step of evaporating the solvent from the liquid film to precipitate a solid of the sublimable substance on the upper surface of the substrate; A flatness measurement step of measuring the flatness of the surface of the solid of the sublimable substance by measuring the height positions of the surface of the solid of the sublimable substance at a plurality of positions on the upper surface of the substrate after the solid of the sublimable substance is precipitated by the evaporation of the solvent in the precipitation step; 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 the solid of the sublimable substance when it is determined in the flatness determination step that the flatness is within the reference flatness range.

2. The substrate processing method according to claim 1, further comprising a solid removal step of removing the solid of the sublimable substance from the upper surface of the substrate by supplying a removal liquid to the upper surface of the substrate when it is determined in the flatness determination step that the flatness is not within the reference flatness range.

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