Substrate processing method and apparatus

Abstract

To process a substrate without reducing throughput or increasing cost of manufacture by rotating the substrate in such a manner that the processing is appropriate based on a predetermined relationship.SOLUTION: In an entire surface coating step (step S10), a substrate is rotated at a rotation speed adjusted to obtain a target solidified film thickness based on a relationship of a concentration, the target solidified film thickness and the rotation speed. Therefore, in accordance with a concentration of a sublimable material, the substrate is rotated at the substrate rotation speed adapted to the relationship of the concentration and the target solidified film thickness, and a desired solidified film of the target solidified film thickness can be formed. As a result, it is not necessary to adjust again a concentration of a solidified film forming liquid, etc., and the substrate can be processed without reducing throughput or increasing cost of manufacture.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a substrate processing method and apparatus for forming a pattern on a substrate such as a semiconductor substrate, a substrate for an FPD (Flat Panel Display) such as a liquid crystal display or an organic EL (Electroluminescence) display device, a glass substrate for a photomask, or a substrate for an optical disk, and drying the substrate on which the pattern has been formed. [Background technology]

[0002] Conventionally, one of the substrate processing methods of this type is sublimation drying, which uses a solidified film-forming liquid containing a sublimable substance (see, for example, Patent Document 1).

[0003] In Patent Document 1, a substrate on which a pattern has been formed is treated with a chemical solution, and then the chemical solution is replaced with a replacement liquid that has a high affinity for the sublimable substance. Next, a solidified film-forming liquid containing a sublimable substance and a solvent, with the sublimable substance adjusted to a certain concentration, is supplied to the upper surface of the substrate on which the pattern has been formed. Then, after the pattern on the substrate is covered with the solidified film-forming liquid, the solvent is evaporated from the solidified film-forming liquid supplied to the substrate. As a result, a solidified film made of the sublimable substance is formed over the entire upper surface of the substrate. The solidified film is then removed from the substrate by sublimating it. This allows the entire upper surface of the substrate to dry while preventing the pattern from collapsing due to liquids such as the chemical solution and the replacement liquid.

[0004] It is known that in this sublimation drying, the pattern collapse rate depends on the relationship between the height of the pattern formed on the substrate and the height of the solidified film formed over the entire upper surface of the substrate. That is, as shown in FIG. 11 of Patent Document 1, the collapse rate is low within a predetermined range of the embedding rate, which indicates the ratio of the height of the solidified film to the height of the pattern, centered around 100%. On the other hand, the collapse rate increases as the embedding rate deviates from the predetermined range. In other words, when the embedding rate is outside the predetermined range including 100%, processing failure occurs.

[0005] Therefore, a substrate processing method has been proposed that prevents such processing defects (see, for example, Patent Document 2).

[0006] In Patent Document 2, the concentration of a sublimable substance in a solidified film-forming liquid is determined based on the rate at which the film thickness of the liquid film of the solidified film-forming liquid supplied to the substrate decreases. Since there is a correlation between the concentration of the sublimable substance and the thickness of the solidified film, the appropriateness of the process is determined based on the concentration of the sublimable substance in the solidified film-forming liquid. That is, if the process is determined to be appropriate, the process is continued to form a solidified film and allow sublimation drying to occur. On the other hand, if the process is determined to be inappropriate, the formation of the solidified film is stopped and the solidified film-forming liquid is removed. This prevents the substrate from being subjected to inappropriate processing. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 2020-4948 [Patent Document 2] Japanese Patent Publication No. 2020-107842 Summary of the Invention [Problem to be solved by the invention]

[0008] However, the conventional example having such a configuration has the following problems. In other words, in conventional apparatuses, if the process is determined to be inappropriate, the process must be stopped midway and the concentration of the solidifying film-forming solution must be adjusted to start the solidifying film formation again. This can significantly reduce throughput. Furthermore, it is necessary to supply extra solvent or sublimable substance to adjust the concentration of the solidifying film-forming solution. This can increase manufacturing costs.

[0009] The present invention has been made in view of the above circumstances, and aims to provide a substrate processing method and apparatus that can process substrates without reducing throughput or increasing manufacturing costs by rotating the substrate so as to perform appropriate processing based on a predetermined relationship. [Means for solving the problem]

[0010] In order to achieve the above object, the present invention has the following configuration. That is, the invention of claim 1 provides a substrate processing method for drying a substrate on which a pattern is formed, comprising: a solidified film forming liquid supplying step of supplying a solidified film forming liquid containing a sublimable substance and a solvent onto the substrate; an entire surface application step of forming a liquid film of the solidified film forming liquid by rotating the substrate and spreading the solidified film forming liquid over the entire upper surface of the substrate; a solidified film forming step of forming a solidified film containing the sublimable substance over the entire upper surface of the substrate by evaporating the solvent from the liquid film of the solidified film forming liquid and precipitating the sublimable substance from the liquid film of the solidified film forming liquid; and a sublimation step of removing the solidified film from the substrate by sublimating the sublimable substance, wherein the entire surface application step comprises rotating the substrate at a solidified film formation rotation speed based on a relationship between a concentration of the sublimable substance in the solidified film formation liquid, a target solidified film thickness which is a desired thickness of the solidified film formed on the entire upper surface of the substrate by precipitating the sublimable substance from the liquid film of the solidified film formation liquid, and a solidified film formation rotation speed which is a rotation speed of the substrate for forming a solidified film of the target solidified film thickness when the concentration of the sublimable substance in the solidified film formation liquid is a predetermined concentration. 、 the relationship is expressed by an approximation formula that represents a change in the target solidified film thickness with respect to a change in either the concentration or the rotation speed for forming the solidified film, the rotation speed for forming the solidified film is determined based on the approximation formula, The substrate processing method is such that the approximate formula is the following formula (1) or (2). (1) y = ax however, y: Thickness of the solidified film a: Slope that changes depending on the rotation speed for solidified film formation x: concentration of sublimable substance in solidified film forming solution (2) y = y 0 +be -z / c however, y: Thickness of the solidified film y 0 : Coefficient that changes depending on the concentration of sublimable substances in the solidified film-forming solution b: Coefficient that changes depending on the concentration of the sublimable substance in the solidified film-forming liquid e: Napier's number z: Rotation speed for solidified film formation c: Coefficient that changes depending on the concentration of the sublimable substance in the solidified film-forming liquid

[0011] [Actions and Effects] According to the invention described in claim 1, a solidifying film forming liquid supplying step supplies a solidifying film forming liquid to a substrate. A full-surface application step applies and spreads the solidifying film forming liquid over the entire upper surface of the substrate. A solidifying film forming step evaporates the solvent from the liquid film of the solidifying film forming liquid, forming a solidifying film over the entire upper surface of the substrate. A sublimation step sublimates the solidifying film and removes it from the substrate. The substrate is processed through this series of steps, and in the full-surface application step, the substrate is rotated at a solidifying film formation rotation speed based on the relationship between the concentration, the target solidifying film thickness, and the solidifying film formation rotation speed. Therefore, a solidifying film with the desired target solidifying film thickness can be formed by rotating the substrate at a substrate rotation speed that matches the relationship between the concentration and the target solidifying film thickness, depending on the concentration of the sublimable substance. As a result, there is no need to readjust the concentration of the solidifying film forming liquid, and substrates can be processed without reducing throughput or increasing manufacturing costs.

[0012] The invention of claim 2 is a substrate processing method for drying a substrate on which a pattern is formed, comprising: a solidified film forming liquid supplying step of supplying a solidified film forming liquid containing a sublimable substance and a solvent onto the substrate; an entire surface application step of forming a liquid film of the solidified film forming liquid by rotating the substrate and spreading the solidified film forming liquid over the entire upper surface of the substrate; and a solidified film containing the sublimable substance by evaporating the solvent from the liquid film of the solidified film forming liquid and precipitating the sublimable substance from the liquid film of the solidified film forming liquid. and a sublimation step of sublimating the solidified film to remove the solidified film from the substrate, wherein the entire surface application step rotates the substrate at a liquid film formation rotation speed based on a relationship between a concentration of the sublimable substance in the solidified film formation liquid, a target liquid film thickness which is a desired thickness of the liquid film of the solidified film formation liquid, and a liquid film formation rotation speed which is a rotation speed of the substrate for forming a liquid film of the target liquid film thickness when the concentration of the sublimable substance in the solidified film formation liquid is a predetermined concentration, the relationship is expressed by an approximation formula that represents a change in the target liquid film thickness with respect to a change in either the concentration or the liquid film formation rotation speed, the liquid film formation rotation speed is determined based on the approximation formula, The substrate processing method is such that the approximate formula is the following formula (1) or (2). (1) y = ax however, y: Thickness of the solidified film a: Slope that changes depending on the rotation speed for solidified film formation x: concentration of sublimable substance in solidified film forming solution (2) y = y 0 +be -z / c however, y: Thickness of the solidified film y 0 : Coefficient that changes depending on the concentration of sublimable substances in the solidified film-forming solution b: Coefficient that changes depending on the concentration of the sublimable substance in the solidified film-forming liquid e: Napier's number z: Rotation speed for solidified film formation c: Coefficient that changes depending on the concentration of the sublimable substance in the solidified film-forming liquid

[0013] [Actions and Effects] According to the invention described in claim 2, a solidifying film forming liquid supplying step supplies a solidifying film forming liquid to a substrate. A full-surface application step applies and spreads the solidifying film forming liquid over the entire upper surface of the substrate. A solidifying film forming step evaporates the solvent from the liquid film of the solidifying film forming liquid, forming a solidifying film over the entire upper surface of the substrate. A sublimation step sublimates the solidifying film and removes it from the substrate. The substrate is processed through this series of steps, and in the full-surface application step, the substrate is rotated at a liquid film formation rotation speed based on the relationship between the concentration, the target liquid film thickness, and the liquid film formation rotation speed. Therefore, a liquid film with the desired target liquid film thickness can be formed by rotating the substrate at a substrate rotation speed that matches the relationship between the concentration and the target liquid film thickness depending on the concentration of the sublimable substance. As a result, there is no need to readjust the concentration of the solidifying film forming liquid, and substrates can be processed without reducing throughput or increasing manufacturing costs.

[0014] In the present invention, the relationship is a correlation between the concentration, the target solidified film thickness, and the solidified film formation rotation speed, and the correlation is expressed by an approximate formula that represents a change in the target solidified film thickness with respect to a change in either the concentration or the solidified film formation rotation speed, and the solidified film formation rotation speed is preferably determined based on the approximate formula. 。

[0015] The relationship is a correlation between the concentration, the target solidified film thickness, and the rotation speed for forming the solidified film. This correlation is expressed by an approximate formula that shows the change in the target solidified film thickness with respect to a change in either the concentration or the rotation speed for forming the solidified film. By using this approximate formula, the rotation speed for forming the solidified film that is appropriate for processing can be determined.

[0016] In the present invention, the relationship is a correlation between the concentration, the target liquid film thickness, and the liquid film formation rotation speed, and the correlation is expressed by an approximation formula that represents a change in the target liquid film thickness with respect to a change in either the concentration or the liquid film formation rotation speed, and the liquid film formation rotation speed is preferably determined based on the approximation formula. 。

[0017] The relationship is a correlation between the concentration, the target liquid film thickness, and the liquid film formation rotation speed. This correlation is expressed by an approximate formula that shows the change in the target liquid film thickness with respect to a change in either the concentration or the liquid film formation rotation speed. By using this approximate formula, the liquid film formation rotation speed that is appropriate for processing can be determined.

[0018] In the present invention, when the concentration of the sublimable substance in the solidified film forming liquid varies from the predetermined concentration, it is preferable to determine the solidified film forming rotation speed or the liquid film forming rotation speed in accordance with the variation in concentration based on the relationship (see claim 3 ).

[0019] The solidified film formation rotation speed or liquid film formation rotation speed that is appropriate for processing can be determined based on the concentration and the relationship between the target solidified film thickness and the solidified film formation rotation speed, or based on the target liquid film thickness and the liquid film formation rotation speed.

[0020] In the present invention, it is preferable that in the entire surface coating step, before rotating the substrate at the solidified film formation rotational speed or the liquid film formation rotational speed, the substrate is rotated at a rotational speed lower than the solidified film formation rotational speed and the liquid film formation rotational speed in order to spread the solidified film formation liquid over the entire upper surface of the substrate (see claims 20). 4 )

[0021] The solidified film forming liquid can be supplied at a rotation speed lower than the solidified film forming rotation speed and the liquid film forming rotation speed, which prevents the solidified film forming liquid from scattering and reduces consumption of the solidified film forming liquid.

[0022] In the present invention, it is preferable to measure the concentration of the solidifying film forming liquid before the solidifying film forming liquid supplying step (claim 5 ).

[0023] Fluctuations in concentration can be detected before the solidified film forming liquid is supplied to the substrate, so that the solidified film forming rotation speed or the liquid film forming rotation speed can be changed with ample time to spare.

[0024] In the present invention, it is preferable that the concentration of the solidifying film forming liquid is measured on the upper surface of the substrate in the solidifying film forming liquid supplying step (see claim 1). 6 ).

[0025] Even if there is an abnormality in the supply system of the solidified film forming liquid, the fluctuation in concentration can be detected, and therefore, inappropriate processing due to the fluctuation in concentration can be reliably prevented.

[0026] Also, claims 7 The invention described in the item (1) above comprises a spinning holder that holds a substrate on which a pattern is formed in a horizontal position and rotates the substrate in a horizontal plane, and a solidified film forming liquid supply unit that supplies a solidified film forming liquid containing a sublimable substance and a solvent to an upper surface of the substrate held by the spinning holder, wherein the solidified film forming liquid supplied to the upper surface of the substrate from the solidified film forming liquid supply unit is spread over the entire upper surface of the substrate by rotating the spinning holder to rotate the substrate, thereby forming a liquid film of the solidified film forming liquid, the solvent is evaporated from the liquid film of the solidified film forming liquid to precipitate the sublimable substance from the liquid film of the solidified film forming liquid, and a solidified film containing the sublimable substance is formed over the entire upper surface of the substrate, and the solidified film forming liquid a storage unit that stores in advance a relationship between a concentration of the sublimable substance in the solidified film forming solution, a target solidified film thickness that is a desired thickness of the solidified film formed on the entire upper surface of the substrate by deposition of the sublimable substance from the liquid film of the solidified film forming solution, and a solidified film formation rotational speed that is a rotational speed of the substrate for forming a solidified film of the target solidified film thickness when the concentration of the sublimable substance in the solidified film forming solution is a predetermined concentration; and a control unit that controls the rotation holding unit so that the substrate rotates at the solidified film formation rotational speed based on the relationship stored in the storage unit. 、 the relationship stored in the storage unit is expressed by an approximation formula that represents a change in the target solidified film thickness with respect to a change in either the concentration or the solidified film formation rotation speed; The control unit reading the approximation formula from the storage unit, and determining the solidified film formation rotation speed based on the approximation formula; The substrate processing apparatus has the following approximate formula (1) or (2): (1) y = ax however, y: Thickness of the solidified film a: Slope that changes depending on the rotation speed for solidified film formation x: concentration of sublimable substance in solidified film forming solution (2) y = y 0 +be -z / c however, y: Thickness of the solidified film y0: Coefficient that changes depending on the concentration of the sublimable substance in the solidified film-forming liquid b: Coefficient that changes depending on the concentration of the sublimable substance in the solidified film-forming liquid e: Napier's number z: Rotation speed for solidified film formation c: Coefficient that changes depending on the concentration of the sublimable substance in the solidified film-forming liquid

[0027] [Action / Effect] Claim 7 According to the invention described in the publication, the control unit rotates the substrate using a spin holder, spreads a solidified film forming liquid over the entire upper surface of the substrate, evaporates the solvent from the liquid film of the solidified film forming liquid to form a solidified film containing a sublimable substance over the entire upper surface of the substrate, and sublimes the solidified film to remove it from the substrate, thereby processing the substrate. In this process, the control unit controls the spin holder so that the substrate rotates at a solidified film formation rotation speed based on the relationship stored in the memory unit. Therefore, depending on the concentration of the sublimable substance, the substrate can be rotated at a substrate rotation speed that matches the relationship between the concentration and the target liquid film thickness, thereby forming a liquid film with the desired target liquid film thickness. As a result, there is no need to readjust the concentration of the solidified film forming liquid, and substrates can be processed without reducing throughput or increasing manufacturing costs.

[0028] Also, claims 8The invention described in the item (1) above comprises a spinning holder that holds a substrate on which a pattern is formed in a horizontal position and rotates the substrate in a horizontal plane, and a solidified film forming liquid supply unit that supplies a solidified film forming liquid containing a sublimable substance and a solvent to an upper surface of the substrate held by the spinning holder, wherein the solidified film forming liquid supplied to the upper surface of the substrate from the solidified film forming liquid supply unit is spread over the entire upper surface of the substrate by rotating the spinning holder to rotate the substrate, thereby forming a liquid film of the solidified film forming liquid, and the solvent is evaporated from the liquid film of the solidified film forming liquid to precipitate the sublimable substance from the liquid film of the solidified film forming liquid, thereby forming a solidified film containing the sublimable substance. a storage unit that stores in advance a relationship between a concentration of the sublimable substance in the solidified film forming liquid, a target liquid film thickness that is a desired thickness of the liquid film of the solidified film forming liquid formed on the upper surface of the substrate, and a liquid film formation rotation speed that is a rotation speed of the substrate for forming a liquid film of the target liquid film thickness when the concentration of the sublimable substance in the solidified film forming liquid is a predetermined concentration; and a control unit that controls the rotation holding unit so that the substrate rotates at the liquid film formation rotation speed based on the relationship stored in the storage unit. 、 the relationship stored in the storage unit is expressed by an approximation formula that represents a change in the target liquid film thickness with respect to a change in either the concentration or the liquid film formation rotation speed, The control unit reading the approximation formula from the storage unit, and determining the liquid film formation rotation speed based on the approximation formula; The substrate processing apparatus has the following approximate formula (1) or (2): (1) y = ax however, y: Thickness of the solidified film a: Slope that changes depending on the rotation speed for solidified film formation x: concentration of sublimable substance in solidified film forming solution (2) y = y 0 +be -z / c however, y: Thickness of the solidified film y 0 : Coefficient that changes depending on the concentration of sublimable substances in the solidified film-forming solution b: Coefficient that changes depending on the concentration of the sublimable substance in the solidified film-forming liquid e: Napier's number z: Rotation speed for solidified film formation c: Coefficient that changes depending on the concentration of the sublimable substance in the solidified film-forming liquid

[0029] [Action / Effect] Claim 8 According to the invention described in the publication, the control unit rotates the substrate using a spin holder, spreads a solidified film forming liquid over the entire upper surface of the substrate, evaporates the solvent from the liquid film of the solidified film forming liquid to form a solidified film containing a sublimable substance over the entire upper surface of the substrate, and sublimes the solidified film to remove it from the substrate, thereby processing the substrate. In this process, the control unit controls the spin holder so that the substrate rotates at a liquid film formation rotation speed based on the relationship stored in the memory unit. Therefore, depending on the concentration of the sublimable substance, the substrate can be rotated at a substrate rotation speed that matches the relationship between the concentration and the target liquid film thickness, thereby forming a liquid film with the desired target liquid film thickness. As a result, there is no need to readjust the concentration of the solidified film forming liquid, and substrates can be processed without reducing throughput or increasing manufacturing costs.

[0030] In the present invention, it is preferable that the relationship stored in the storage unit is a correlation between the concentration, the target solidified film thickness, and the solidified film formation rotation speed, and the correlation is expressed by an approximation formula that represents a change in the target solidified film thickness with respect to a change in either the concentration or the solidified film formation rotation speed, and the control unit reads out the correlation between the concentration, the target solidified film thickness, and the solidified film formation rotation speed from the storage unit, and determines the solidified film formation rotation speed based on the correlation. 。

[0031] The relationship is a correlation between the concentration, the target solidified film thickness, and the rotation speed for forming the solidified film. This correlation is expressed by an approximation formula that shows the change in the target solidified film thickness with respect to a change in either the concentration or the rotation speed for forming the solidified film. By using this correlation, the rotation speed for forming the solidified film that is appropriate for processing can be determined.

[0032] In the present invention, it is preferable that the relationship stored in the memory unit is a correlation between the concentration, the target liquid film thickness, and the liquid film formation rotation speed, and the correlation is expressed by an approximation formula that represents a change in the target liquid film thickness with respect to a change in either the concentration or the liquid film formation rotation speed, and the control unit reads out the correlation between the concentration, the target liquid film thickness, and the liquid film formation rotation speed from the memory unit, and determines the liquid film formation rotation speed based on the correlation. 。

[0033] The relationship is a correlation between the concentration, the target liquid film thickness, and the liquid film formation rotation speed. This correlation is expressed by an approximation formula that shows the change in the target liquid film thickness with respect to a change in either the concentration or the liquid film formation rotation speed. By using this correlation, the control unit can determine the liquid film formation rotation speed that is appropriate for processing.

[0034] In the present invention, it is preferable that, before controlling the spin holding unit to rotate the substrate at the solidified film formation rotational speed or the liquid film formation rotational speed, the control unit controls the spin holding unit to rotate the substrate at a rotational speed lower than the solidified film formation rotational speed and the liquid film formation rotational speed in order to spread the solidified film formation liquid over the entire upper surface of the substrate (see claim 1). 9 ).

[0035] The control unit controls the rotation holding unit at a rotation speed lower than the solidified film formation rotation speed and the liquid film formation rotation speed, thereby allowing the solidified film formation liquid to be supplied at a low rotation speed, thereby preventing the solidified film formation liquid from scattering and reducing consumption of the solidified film formation liquid.

[0036] In the present invention, it is preferable that the substrate processing apparatus further includes a concentration detection unit that detects the concentration of the sublimable substance in the solidified film formation liquid, and when the detection result of the concentration detection unit indicates that the concentration of the sublimable substance in the solidified film formation liquid has varied from the predetermined concentration, the control unit determines the solidified film formation rotation speed or the liquid film formation rotation speed in accordance with the variation in concentration based on the relationship stored in the storage unit (see claim 1).10 ).

[0037] When the concentration of the sublimable substance in the solidified film forming liquid is found to have varied from a predetermined concentration based on the detection result of the concentration detection unit, the control unit determines the solidified film formation rotation speed or the liquid film formation rotation speed in accordance with the variation in concentration based on the relationship in the memory unit. Therefore, even when it is determined that the process is inappropriate due to the variation in the concentration of the solidified film forming liquid, the process can be performed at the solidified film formation rotation speed or the liquid film formation rotation speed that is appropriate for the process.

[0038] In the present invention, it is preferable that the concentration detection unit detects the concentration of the sublimable substance in the solidified film formation liquid present in the solidified film formation liquid supply unit (see claim 1). 11 ).

[0039] Fluctuations in concentration can be detected before the solidified film forming liquid is supplied to the substrate, and therefore the solidified film forming rotation speed or the liquid film forming rotation speed can be changed quickly.

[0040] In the present invention, it is preferable that the concentration detection unit detects the concentration of the sublimable substance in the solidified film formation liquid supplied to the upper surface of the substrate held by the rotation holding unit (see claim 1). 12 ).

[0041] Even if there is an abnormality in the solidified film forming liquid supply unit, the fluctuation in concentration can be detected, and therefore, inappropriate processing due to the fluctuation in concentration can be reliably prevented.

[0042] In the present invention, it is preferable that the substrate processing apparatus further includes an evaporation promotion unit that promotes evaporation of the solvent from the liquid film of the solidified film forming liquid, and the control unit controls the evaporation promotion unit so as to promote evaporation of the solvent from the liquid film (see claim 1). 13 ).

[0043] The evaporation promoter accelerates the evaporation of the solvent from the liquid film, thereby shortening the time required to form a solidified film.

[0044] In the present invention, it is preferable that the substrate processing apparatus further includes a sublimation accelerator that accelerates the sublimation of the solidified film from the substrate, and the control unit controls the sublimation accelerator so as to accelerate the sublimation of the solidified film from the substrate (see claim 1). 14 ).

[0045] The sublimation promoter promotes the sublimation of the solidified film, thereby shortening the time required for the drying process. [Effects of the Invention]

[0046] According to the substrate processing method and substrate processing apparatus of the present invention, a liquid film having a desired target solidified film thickness or target liquid film thickness can be formed by rotating the substrate at a substrate rotation speed that is suited to the relationship between the concentration of the sublimable substance and the target solidified film thickness or target liquid film thickness, thereby eliminating the need to readjust the concentration of the solidified film-forming liquid, and allowing substrate processing without reducing throughput or increasing manufacturing costs. [Brief explanation of the drawings]

[0047] [Figure 1] 1 is a plan view showing a schematic configuration of a substrate processing apparatus according to a first embodiment. [Figure 2] 1 is a block diagram of a substrate processing apparatus according to a first embodiment. [Figure 3] FIG. 2 is a diagram showing the configuration of a processing unit and a solidified film forming liquid generating unit. [Figure 4] 1 is a graph showing an example of measurement of solidified film thickness (liquid film thickness). [Figure 5] FIG. 1 is a schematic diagram showing an example of a concentration calibration curve for cyclohexanone oxime. [Figure 6] FIG. 1 is a schematic diagram showing an example of a rotational speed calibration curve for cyclohexanone oxime. [Figure 7] FIG. 1 is a schematic diagram showing an example of a concentration calibration curve for pinacoline oxime. [Figure 8] FIG. 1 is a schematic diagram showing an example of a rotational speed calibration curve for pinacoline oxime. [Figure 9] 1 is a flowchart illustrating an example of substrate processing. [Figure 10] 10A and 10B are schematic diagrams showing a state of a substrate to which a solidifying film forming liquid has been supplied. [Figure 11] 3A to 3C are schematic diagrams showing the state of a substrate during the process of forming a solidified film. [Figure 12] 3A to 3C are schematic diagrams showing the state of a substrate during the process of forming a solidified film. [Figure 13] FIG. 10 is a schematic diagram showing the state of the substrate during sublimation of the solidified film. [Figure 14] FIG. 2 is a schematic diagram showing the state of the substrate from which the solidified film has been sublimated. [Figure 15] FIG. 10 is a diagram showing the configuration of a processing unit and a solidified film forming solution generating unit in a substrate processing apparatus according to a second embodiment. [Figure 16] FIG. 10 is a block diagram of a substrate processing apparatus according to a second embodiment. [Figure 17] 1 is a flowchart illustrating an example of substrate processing. DETAILED DESCRIPTION OF THE INVENTION

[0048] The present invention will now be described with reference to the following examples. [Example]

[0049] A first embodiment of the present invention will be described below with reference to the drawings.

[0050] <1-1. Overview of substrate processing equipment> FIG. 1 is a plan view showing a schematic configuration of a substrate processing apparatus according to a first embodiment.

[0051] The substrate processing apparatus 1 performs a predetermined process on a substrate W. The predetermined process includes a drying process. The substrate W to be processed is, for example, a semiconductor wafer, a liquid crystal display substrate, an organic electroluminescence (EL) substrate, an FPD (Flat Panel Display) substrate, an optical display substrate, a magnetic disk substrate, an optical disk substrate, a magneto-optical disk substrate, a photomask substrate, or a solar cell substrate. The substrate W has an external appearance of a thin, flat plate. The substrate W has a substantially circular shape in a plan view.

[0052] The substrate processing apparatus 1 includes an indexer unit 3 and a processing block 7. The processing block 7 is connected to the indexer unit 3. The indexer unit 3 supplies substrates W to the processing block 7. The processing block 7 processes the substrates W supplied from the indexer unit 3. The indexer unit 3 retrieves the processed substrates W from the processing block 7.

[0053] For convenience, in this specification, the direction in which the indexer unit 3 and the processing block 7 are aligned is referred to as the "front-rear direction X." The front-rear direction X is horizontal. Within the front-rear direction X, the direction from the processing block 7 toward the indexer unit 3 is referred to as the "front." The direction opposite to the front is referred to as the "rear." The horizontal direction perpendicular to the front-rear direction X is referred to as the "width direction Y." One direction in the "width direction Y" is referred to as the "right" as appropriate. The direction opposite to the right is referred to as the "left." The direction perpendicular to the horizontal direction is referred to as the "vertical direction Z." For reference, in each figure, front, rear, right, left, top, and bottom are indicated as appropriate.

[0054] The indexer unit 3 includes a plurality of (for example, four) carrier placement units 4. Each carrier placement unit 4 places one carrier C thereon. The carrier C accommodates a plurality of substrates W. The carrier C accommodates the substrates W in a horizontal position. The carrier C is, for example, a FOUP (Front Opening Unified Pod), a SMIF (Standard Mechanical Interface), or an OC (Open Cassette).

[0055] The indexer unit 3 is equipped with a transport mechanism 5. The transport mechanism 5 is arranged behind the carrier mounting unit 4. The transport mechanism 5 transports a substrate W. The transport mechanism 5 is accessible to a carrier C mounted on the carrier mounting unit 4. The transport mechanism 5 is equipped with a hand 5a and a hand driving unit 5b. The hand 5a supports the substrate W. The hand driving unit 5b is connected to the hand 5a. The hand driving unit 5b moves the hand 5a. The hand driving unit 5b moves the hand 5a, for example, in the front-rear direction X, the width direction Y, and the vertical direction Z. The hand driving unit 5b rotates the hand 5a, for example, in a horizontal plane.

[0056] The processing block 7 is equipped with a transport mechanism 8. The transport mechanism 8 transports a substrate W. The transport mechanism 8 and the transport mechanism 5 are capable of transferring the substrate W to each other. The transport mechanism 8 is equipped with a hand 8a and a hand driver 8b. The hand 8a supports the substrate W. The hand driver 8b is connected to the hand 8a. The hand driver 8b moves the hand 8a. The hand driver 8b moves the hand 8a, for example, in the front-rear direction X, the width direction Y, and the vertical direction Z. The hand driver 8b rotates the hand 8a, for example, in a horizontal plane.

[0057] The processing block 7 includes a plurality of processing units 11. The processing units 11 are arranged on the sides of the transport mechanism 8. Each processing unit 11 performs processing on the substrate W.

[0058] The processing unit 11 includes a substrate holder 13. The substrate holder 13 holds a substrate W.

[0059] The transport mechanism 8 is accessible to each processing unit 11. The transport mechanism 8 can deliver a substrate W to each substrate holder 13. The transport mechanism 8 can take a substrate W from each substrate holder 13.

[0060] Here, reference is made to Fig. 2. Fig. 2 is a block diagram of the substrate processing apparatus according to the first embodiment.

[0061] The substrate processing apparatus 1 includes a control unit 14. The control unit 14 controls the transfer mechanisms 5 and 8 and the processing unit 11.

[0062] The control unit 14 is realized by a central processing unit (CPU) that executes various processes, a random-access memory (RAM) that serves as a work area for the processes, a storage medium such as a fixed disk, and the like. The control unit 14 has various types of information pre-stored in the storage medium. The information held by the control unit 14 is, for example, transport information for controlling the transport mechanisms 5 and 8. The information held by the control unit 14 is, for example, processing information for controlling the processing unit 11. The processing information is also called a recipe. The control unit 14 is equipped with a memory unit 15. The memory unit 15 pre-stores recipes. The memory unit 15 stores multiple recipes. Each recipe includes the thickness of a solidified film to be formed on the substrate W using a solidified film formation liquid. The memory unit 15 pre-stores relationships, which will be described in detail later. The relationships are the relationships between the concentration of the solidified film formation liquid, the target thickness of the solidified film to be formed by processing, and the rotation speed of the substrate W for forming the solidified film. The relationships have correlations between elements such as concentrations.

[0063] Here, an example of the operation of the above-described substrate processing apparatus 1 will be briefly described.

[0064] The indexer unit 3 supplies unprocessed substrates W to the processing block 7. Specifically, the transport mechanism 5 hands over the substrates W from the carrier C to the transport mechanism 8 of the processing block 7. The processing block 7 distributes the substrates W from the indexer unit 3 to the processing units 11. Specifically, the transport mechanism 8 transports the substrates W from the transport mechanism 5 to the substrate holders 13 of each processing unit 11. The processing units 11 process the substrates W held in the substrate holders 13. The processing units 11 perform, for example, drying processing on the substrates W. After the processing units 11 process the substrates W, the processing block 7 returns the substrates W from the processing units 11 to the indexer unit 3. Specifically, the transport mechanism 8 transports the substrates W from the substrate holders 13 to the transport mechanism 5. The indexer unit 3 recovers the substrates W from the processing block 7. Specifically, the transport mechanism 5 transports the substrates W from the transport mechanism 8 to the carrier C.

[0065] <1-2. Configuration of processing unit 11> Here, reference is made to Fig. 3. Fig. 3 is a diagram showing the configuration of the processing unit and the solidified film forming solution generating unit.

[0066] The processing units 11 are classified as single-wafer processing, i.e., each processing unit 11 processes only one substrate W at a time.

[0067] The processing unit 11 includes a housing 17. The housing 17 has a substantially box shape. The substrate W is processed inside the housing 17. In this embodiment, the inside of the housing 17 is kept at room temperature. The inside of the housing 17 is kept at normal pressure. Therefore, the substrate W is processed in an environment of room temperature and normal pressure.

[0068] The processing unit 11 is equipped with a rotational drive unit 18. At least a portion of the rotational drive unit 18 is installed inside the housing 17. The rotational drive unit 18 is connected to the substrate holding unit 13. The rotational drive unit 18 rotates the substrate holding unit 13. The substrate W held by the substrate holding unit 13 rotates integrally with the substrate holding unit 13. The substrate W rotates in a horizontal plane. The substrate W held by the substrate holding unit 13 rotates around a rotational axis B. The rotational axis B, for example, passes through the center of the substrate W and extends in the vertical direction Z.

[0069] The processing unit 11 includes one or more (e.g., five) supply units 19a, 19b, 19c, 19d, and 19e. Each of the supply units 19a-19e supplies a liquid or a gas to the substrate W. More specifically, each of the supply units 19a-19e supplies a liquid or a gas to the substrate W held on the substrate holder 13. Each of the supply units 19a-19e supplies a liquid or a gas to the upper surface W1 of the substrate W held on the substrate holder 13.

[0070] Specifically, the supply unit 19a supplies a solidified film forming liquid. The solidified film forming liquid contains a sublimable substance and a solvent. As described above, the inside of the housing 17 is at room temperature and atmospheric pressure. Therefore, the solidified film forming liquid is used in an environment at room temperature. The solidified film forming liquid is used in an environment at atmospheric pressure.

[0071] The supply unit 19b supplies a chemical solution, such as an etching solution, which contains at least one of hydrofluoric acid (HF) and buffered hydrofluoric acid (BHF).

[0072] The supply unit 19c supplies a rinse liquid, such as deionized water (DIW).

[0073] The supply unit 19d supplies a substitute liquid, which may be, for example, an organic solvent, such as isopropyl alcohol (IPA).

[0074] The supply unit 19e supplies a first gas. The first gas is, for example, a dry gas. The dry gas has a dew point lower than room temperature. The dew point is, for example, about -76°C. Therefore, the dry gas does not condense at room temperature. The first gas is, for example, air, compressed air, an inert gas, or nitrogen gas.

[0075] The supply unit 19a includes a nozzle 20a. Similarly, each of the supply units 19b-19e includes a nozzle 20b-20e. Each of the nozzles 20a-20e is installed inside the housing 17. The nozzle 20a ejects a solidification film forming liquid. The nozzle 20b ejects a chemical liquid. The nozzle 20c ejects a rinse liquid. The nozzle 20d ejects a substitute liquid. The nozzle 20e ejects or blows out a first gas.

[0076] Each nozzle 20a-20e is movable between a processing position and a standby position. The processing position is, for example, a position above the substrate W held by the substrate holding part 13. The processing position is, for example, a position above the center of the substrate W held by the substrate holding part 13. The center of the substrate W intersects with the rotation axis B. The standby position is, for example, a position not above the substrate W held by the substrate holding part 13.

[0077] Supply unit 19a includes pipe 21a, which is connected to nozzle 20a. Similarly, supply units 19b-19e include pipes 21b-21e, which are connected to nozzles 20b-20e, respectively.

[0078] The supply unit 19a includes a valve 22a. The valve 22a is provided on the pipe 21a. When the valve 22a is open, the nozzle 20a discharges the solidification film formation liquid. When the valve 22a is closed, the nozzle 20a does not discharge the solidification film formation liquid. Similarly, the supply units 19b-19e include valves 22b-22e, respectively. The valves 22b-22e are provided on the pipes 21b-21e. The valves 22b-22e control the supply of the chemical liquid, the rinse liquid, the replacement liquid, and the first gas.

[0079] At least a portion of pipe 21a may be provided outside of housing 17. Pipes 21b-21e may be arranged in the same manner as pipe 21a. Valve 22a may be provided outside of housing 17. Valves 22b-22e may be arranged in the same manner as valve 22a.

[0080] The substrate holder 13 described above corresponds to the "rotary holder" in this invention. The supply unit 19e and the nozzle e described above correspond to the "sublimation promoter" in this invention.

[0081] The processing unit 11 includes a film thickness meter tu in a housing 17 .

[0082] The film thickness meter tu is disposed above the substrate holding unit 13. The film thickness meter tu measures the film thickness of a solidified film formed by the solidified film formation liquid supplied from the supply unit 19a to the substrate W. The film thickness meter tu is preferably a non-contact type that uses, for example, spectral interferometry. Spectroscopic interferometry irradiates light toward the substrate W and receives the reflected light. The reflected light is multiple-reflected light reflected by the surface of the substrate W and the liquid film surface of the solidified film formation liquid, and its intensity changes depending on the phase difference between the reflected light and the liquid film. This reflected light exhibits a unique spectrum that depends on the film thickness. Spectroscopic interferometry measures the film thickness by analyzing this spectrum.

[0083] The film thickness meter tu is a component necessary for measuring the correlation, which will be described later. Therefore, it may be attached to the housing 17 only when necessary, and removed from the housing 17 when not necessary. Since the film thickness meter tu is a component necessary only for measuring the correlation, it is not an essential component for the present invention. In other words, the correlation information, which will be described later, may be collected by another device, and the correlation information may be stored in the substrate processing apparatus 1 and used.

[0084] The substrate processing apparatus 1 includes a solidified film forming liquid generating unit 23. The solidified film forming liquid generating unit 23 generates a solidified film forming liquid.

[0085] The solidified film forming liquid generation unit 23 is provided outside the housing 17. The solidified film forming liquid generation unit 23 is connected in communication with the supply unit 19a. The solidified film forming liquid generation unit 23 is connected to, for example, the pipe 21a. The solidified film forming liquid generation unit 23 sends the solidified film forming liquid to the supply unit 19a.

[0086] The supply unit 19b is connected to a chemical supply source 24b. The chemical supply source 24b is connected to, for example, the pipe 21b. The chemical supply source 24b sends the chemical to the supply unit 19b.

[0087] The supply unit 19c is connected to a rinse liquid supply source 24c, which is connected to, for example, a pipe 21c. The rinse liquid supply source 24c supplies the rinse liquid to the supply unit 19c.

[0088] The supply unit 19d is connected to a substitute fluid supply source 24d, which is connected to, for example, a pipe 21d. The substitute fluid supply source 24d supplies the substitute fluid to the supply unit 19d.

[0089] The supply unit 19e is connected to a first gas supply source 24e. The first gas supply source 24e is connected to, for example, the pipe 21e. The first gas supply source 24e sends a first gas to the supply unit 19e.

[0090] The above-described solidified film forming liquid generation unit 23 may supply the solidified film forming liquid to a plurality of processing units 11. Alternatively, the solidified film forming liquid generation unit 23 may supply the solidified film forming liquid to only one processing unit 11. The same applies to the chemical liquid supply source 24b, the rinse liquid supply source 24c, the replacement liquid supply source 24d, and the first gas supply source 24e.

[0091] 2, the control unit 14 controls the rotary drive unit 18 and the valves 22a-22e. The control unit 14 acquires the detection result of the film thickness meter tu.

[0092] <1-3. Solidified film forming solution> The solidified film forming liquid generated by the solidified film forming liquid generating unit 23 will be described. The solidified film forming liquid contains a sublimable substance and a solvent. For example, the solidified film forming liquid is composed of only a sublimable substance and a solvent.

[0093] A sublimable substance has sublimability. "Sublimability" refers to the property of a single substance, compound, or mixture to undergo a phase transition from solid to gas or from gas to solid without passing through a liquid state.

[0094] The sublimable substance includes, for example, at least one of the following compounds S1 to S4. Compound S1: Pinacoline oxime Compound S2: Acetophenone oxime Compound S3: Cyclohexanone oxime Compound S4: 4-tert-butylphenol

[0095] For example, the sublimable substance consists of at least one of the compounds S1 to S4. In other words, the sublimable substance is any one of the compounds S1 to S4.

[0096] The solvent is a liquid at room temperature. The solvent dissolves the sublimable substance. Therefore, the sublimable substance in the solidified film-forming liquid is dissolved in the solvent. That is, the solidified film-forming liquid contains the solvent and the sublimable substance dissolved in the solvent. The sublimable substance corresponds to the solute of the solidified film-forming liquid.

[0097] The solvent has a relatively high vapor pressure at room temperature. For example, the vapor pressure of the solvent at room temperature is preferably higher than the vapor pressure of the sublimable substance at room temperature. The solvent is, for example, an organic solvent. The solvent is, for example, an alcohol.

[0098] The solvent contains, for example, at least one of the following compounds Q1 to Q10: Compound Q1: Isopropyl alcohol (IPA) Compound Q2: Acetone Compound Q3: Methanol Compound Q4: Ethanol Compound Q5: tert-butanol Compound Q6: 1-propanol Compound Q7: Isobutanol Compound Q8: 1-ethoxy-2-propanol Compound Q9: 1-butanol Compound Q10: Propylene glycol monomethyl ether acetate

[0099] The mass of the sublimable substance contained in the solidified film-forming liquid is smaller than the mass of the solvent contained in the solidified film-forming liquid. In this specification, the concentration (wt%) of the solidified film-forming liquid is (mass of sublimable substance / mass of solidified film-forming liquid) × 100. The mass of the solidified film-forming liquid is (mass of solvent) + (mass of sublimable substance). The concentration (wt%) is preferably in the range of 1 or more and 25 or less.

[0100] <1-4. Configuration of solidified film forming liquid generating unit 23> Please refer to Fig. 3. The solidified film forming liquid producing unit 23 produces a solidified film forming liquid.

[0101] The solidified film forming liquid production unit 23 includes a tank 25. The tank 25 is connected in communication with the supply unit 19a. The tank 25 is connected in communication with the nozzle 20a. In this embodiment, the solidified film forming liquid production unit 23 produces the solidified film forming liquid in the tank 25. The solidified film forming liquid is produced in an environment at room temperature. The solidified film forming liquid is produced in an environment at normal pressure.

[0102] The solidified film forming liquid generating unit 23 stores the generated solidified film forming liquid in a tank 25. The solidified film forming liquid is stored in an environment at room temperature. The solidified film forming liquid is stored in an environment at normal pressure.

[0103] The solidified film forming liquid production unit 23 includes a supply unit 26 and a supply unit 27. The supply unit 26 supplies a sublimable substance to the tank 25. The supply unit 27 supplies a solvent to the tank 25. The sublimable substance and the solvent are mixed in the tank 25. As a result, a solidified film forming liquid containing the sublimable substance and the solvent is produced.

[0104] The supply unit 26 is fluidly connected to the tank 25. The supply unit 26 is further fluidly connected to a sublimable material supply source 28. The sublimable material supply source 28 delivers a sublimable material to the supply unit 26.

[0105] The supply unit 26 includes, for example, a pipe 26a and a valve 26b. The pipe 26a has a first end connected to the tank 25 and a second end connected to a sublimable material supply source 28. The valve 26b is provided on the pipe 26a. By opening and closing the valve 26b, the supply unit 26 can be switched between a state in which the sublimable material is supplied to the tank 25 and a state in which the sublimable material is not supplied to the tank 25.

[0106] The supply unit 27 is connected in fluid communication with the tank 25. The supply unit 27 is further connected in fluid communication with a solvent supply source 29. The solvent supply source 29 delivers a solvent to the supply unit 27.

[0107] Supply unit 27 includes, for example, pipe 27a and valve 27b. Pipe 27a has a first end connected to tank 25 and a second end connected to solvent supply source 29. Valve 27b is provided on pipe 27a. By opening and closing valve 27b, supply unit 27 can be switched between a state in which solvent is supplied to tank 25 and a state in which solvent is not supplied to tank 25.

[0108] The solidified film forming liquid generation unit 23 includes at least one or more (e.g., two) first sensors 31. The first sensors 31 detect the amount of solidified film forming liquid stored in the tank 25. The first sensors 31 are attached to the tank 25, for example. The first sensors 31 detect the height position of the liquid surface of the solidified film forming liquid stored in the tank 25, for example. The first sensors 31 are, for example, liquid level sensors.

[0109] The solidified film forming liquid production unit 23 includes a liquid delivery section 32. The liquid delivery section 32 delivers the solidified film forming liquid from the tank 25 to the supply section 19a.

[0110] The liquid delivery unit 32 includes, for example, a pipe 33, a pump 34, a filter 35, a concentration meter 36, and a joint 37. The pipe 33 is connected to the tank 25. The pump 34 is provided on the pipe 33. The filter 35 is provided on the pipe 33. The joint 37 is connected to the pipe 33. The joint 37 is further connected to the pipe 21a. The pipe 33 and the pipe 21a are connected to each other by the joint 37.

[0111] The pump 34 sends the solidified film forming liquid from the tank 25 to the pipe 21a through the pipe 21a and the joint 37. As a result, the pump 34 sends the solidified film forming liquid from the tank 25 to the supply unit 19a. The filter 35 filters the solidified film forming liquid flowing through the pipe 21a. The filter 35 removes foreign matter from the solidified film forming liquid. The concentration meter 36 measures the concentration of the solidified film forming liquid flowing through the pipe 21a. The concentration meter 36 measures the concentration of the sublimable substance in the solidified film forming liquid. The concentration meter 36 is a non-contact type concentration meter. The concentration meter 36 irradiates light of a predetermined intensity and calculates the concentration based on the intensity of the light transmitted through the solidified film forming liquid. The concentration meter 36 measures the concentration, which is the mass ratio of the sublimable substance in the solidified film forming liquid, based on, for example, absorbance.

[0112] The above-mentioned concentration meter 36 corresponds to the "concentration detection unit" in the present invention.

[0113] Referring to Fig. 2, the control unit 14 controls the solidified film forming liquid generation unit 23. The control unit 14 is electrically connected to the solidified film forming liquid generation unit 23 so as to be able to communicate with the solidified film forming liquid generation unit 23. The control unit 14 controls the supply units 26 and 27 and the liquid delivery unit 32. The control unit 14 controls the valve 26b, the valve 27b, and the pump 34. The control unit 14 acquires the detection result of the first sensor 31. The control unit 14 acquires the detection result of the concentration meter 36.

[0114] The control unit 14 has solidified film forming liquid generation information for controlling the solidified film forming liquid generation unit 23. The solidified film forming liquid generation information is stored in advance in a storage medium of the control unit 14. The solidified film forming liquid generation information includes the concentration of the sublimable substance in the solidified film forming liquid.

[0115] The control unit 14, as necessary, refers to the memory unit 15. The memory unit 15 stores in advance the relationship between the concentration of the sublimable substance in the solidified film forming solution, the target film thickness, which is the desired film thickness of the solidified film formed on the substrate W by the solidified film forming solution, and the solidified film formation rotation speed, which is the rotation speed of the substrate for forming a solidified film with the target film thickness when the concentration of the solidified film forming solution is a predetermined concentration.

[0116] The nozzle 20a described above corresponds to the "solidified film forming liquid supply unit" in this invention. The target film thickness described above corresponds to the "target solidified film thickness" in this invention.

[0117] <2-1. Film Thickness Measurement Example>

[0118] Here, reference is made to Figure 4. Figure 4 is a graph showing an example of measurement of solidified film thickness (liquid film thickness).

[0119] FIG. 4 shows an example of measurement using a solidified film-forming liquid in which the sublimable substance is pinacoline oxime and the solvent is isopropyl alcohol.

[0120] Specifically, the solidified film formation liquid is supplied to the substrate W, and the substrate W is rotated at a predetermined speed. During this process, the thickness of the liquid film of the solidified film formation liquid supplied to the upper surface of the substrate W is continuously measured using a film thickness meter tu. The change in film thickness is graphed. The solidified film formation liquid supplied to the substrate W and covering the entire upper surface of the substrate W has a certain liquid film thickness. As the substrate W rotates, the solidified film formation liquid flows toward the outer periphery of the substrate W and splashes around. Therefore, as shown by the dashed two-dot line with an arrow in Figure 4, the thickness of the liquid film gradually decreases over time from the point at which measurement of the liquid film thickness begins.

[0121] In this example, precipitation of the sublimable substance begins just before the position indicated by the downward arrow. As a result, the fluidity of the solidified film-forming liquid decreases, and the measured film thickness becomes approximately constant. After this, precipitation of the sublimable substance progresses until the entire film becomes a solidified film. Therefore, the film thickness at the point indicated by the downward arrow is taken as the film thickness of the solidified film formed by the solidified film-forming liquid. The film thickness at the point indicated by the downward arrow also marks the boundary between a light-transmitting liquid film through which reflected light returns from the top surface of the substrate W and a light-opaque solid film through which reflected light does not return from the top surface of the substrate W. Therefore, the film thickness at this point is also the film thickness of the liquid film of the solidified film-forming liquid. This is because the film is still in the state of a solidified film-forming liquid when the sublimable substance begins to precipitate.

[0122] <2-2. Concentration calibration curve of cyclohexanone oxime> Here, reference is made to Figure 5. Figure 5 is a schematic diagram showing an example of a concentration calibration curve for cyclohexanone oxime.

[0123] A concentration calibration curve will be described below when cyclohexanone oxime is used as the sublimable substance in the solidified film forming solution. This concentration calibration curve is obtained for each rotation speed of the substrate W by the rotation drive unit 18, and shows the relationship between the concentration of the sublimable substance in the solidified film forming solution and the thickness of the solidified film formed by the solidified film forming solution. In other words, this relationship is a correlation between the concentration of the sublimable substance in the solidified film forming solution, the thickness of the solidified film formed by the solidified film forming solution, and the rotation speed of the substrate W. Furthermore, this concentration calibration curve shows the change in solidified film thickness relative to the change in concentration.

[0124] For example, the rotation speed of the substrate W was set to 500 rpm, 1000 rpm, and 1500 rpm, and the thickness of the solidified film formed was measured when the concentration was changed at each rotation speed. In Figure 5, the dashed two-dot line is an approximation line. In this case, the approximation line is expressed by the following mathematical formula (1). Note that the meanings of the symbols in formula (1) are: y: thickness of the solidified film [nm], a: slope [nm / wt%], x: concentration [wt%] of the sublimable substance in the solidified film-forming solution.

[0125] y=ax …… (1)

[0126] When using this concentration calibration curve, the following procedure is carried out.

[0127] For example, if the thickness of a certain solidified film is the target thickness tg and the rotation speed of the substrate W driven by the rotation drive unit 18 is 1000 rpm, a line is drawn horizontally from the target thickness on the vertical axis, and a perpendicular line is drawn from the point corresponding to the two-dot chain line connecting the triangles in Figure 5. The concentration cn0 at the point where the perpendicular line intersects with the horizontal axis is the concentration of sublimable substance required to obtain the target film thickness at the specified rotation speed of 1000 rpm. From this concentration calibration curve, it can be seen that the slope of the approximation equation becomes steeper as the rotation speed becomes lower, indicating higher sensitivity to concentration fluctuations in the solidified film-forming solution.

[0128] Now, let's assume that the concentration of the solidified film-forming solution increases from concentration cn0 to concentration cn1. Using Figure 5, if a perpendicular line is drawn from concentration cn1 and a rotation speed of 1500 rpm is used, which is close to the intersection of the horizontal line for the target film thickness tg and the perpendicular line for concentration cn1, the target film thickness tg can be formed at concentration cn1. Using equation (1), the rotation speed can be similarly calculated from the slope a when the film thickness y is fixed and the concentration x is changed.

[0129] An approximation of this formula (1) is stored in advance in the memory unit 15, and the control unit 14 operates the solidified film forming solution generating unit 23 to generate and supply a solidified film forming solution of the required concentration. This allows a solidified film of the target thickness to be formed at a predetermined rotation speed. If the concentration fluctuates, the rotation speed is adjusted as described above.

[0130] <2-3. Rotational speed calibration curve for cyclohexanone oxime> Here, reference is made to Figure 6. Figure 6 is a schematic diagram showing an example of a rotational speed calibration curve for cyclohexanone oxime.

[0131] A rotation speed calibration curve will be described below when cyclohexanone oxime is used as the sublimable substance in the solidified film forming solution. This rotation speed calibration curve is obtained for each concentration of the sublimable substance in the solidified film forming solution, and shows the relationship between the rotation speed of the substrate W and the solidified film thickness of the solidified film forming solution. In other words, this relationship is a correlation between the concentration of the sublimable substance in the solidified film forming solution, the film thickness of the solidified film formed by the solidified film forming solution, and the rotation speed of the substrate W. Furthermore, this rotation speed calibration curve shows the change in solidified film thickness relative to the change in rotation speed.

[0132] For example, the thickness of the solidified film formed was measured when the rotation speed was changed for the solidified film forming solution with concentrations of 24.4 wt%, 20.5 wt%, 17.7 wt%, 11.4 wt%, and 6.1 wt%. In Figure 6, the approximate line is shown by the two-dot chain line. In this case, the approximate line is expressed by the following equation (2). Note that the meanings of the symbols in equation (2) are: y: thickness of the solidified film [nm], y0: coefficient [nm], a: coefficient [nm], b: coefficient [rpm], and x: rotation speed of the substrate W [rpm].

[0133] y=y0+ae -x / b … (2)

[0134] When using this rotation speed calibration curve, the following procedure is carried out.

[0135] For example, if the thickness of a certain solidified film is the target thickness tg and the solidified film is formed using a solidified film-forming solution with a concentration of 17.7 wt% (concentration cn0), a line is drawn horizontally from the target thickness tg on the vertical axis, and a perpendicular line is dropped from the point where it intersects with the two-dot chain line connecting the triangles in Figure 6. The rotation speed rv0 at the point where the perpendicular line intersects with the horizontal axis is the rotation speed required to obtain the target thickness using a solidified film-forming solution with a concentration of 17.7 wt%.

[0136] Now, let's say the concentration of the solidified film-forming liquid increases from 17.7 wt% (concentration cn0) to 20.5 wt% (concentration cn1). Using Figure 6, draw a perpendicular line from the target film thickness tg to the intersection of the horizontal line and the approximation line for 20.5 wt% (concentration cn1), and use the rotation speed rv1 where the perpendicular line intersects to form the target film thickness tg at concentration cn1. Using equation (2), the rotation speed x can be similarly calculated from coefficients y0, a, and b when the film thickness y is fixed and the concentration is changed.

[0137] An approximation of this formula (2) is stored in advance in the memory unit 15, and the control unit 14 operates the rotation drive unit 18 to generate and supply a solidified film forming solution of the required concentration. The substrate W is rotated at the required rotation speed. This allows a solidified film of the target thickness to be formed at the specified rotation speed. If the concentration fluctuates, the rotation speed is adjusted as described above.

[0138] <2-4. Pinacoline oxime concentration calibration curve> Please refer to Figure 7. Figure 7 is a schematic diagram showing an example of a concentration calibration curve for pinacoline oxime.

[0139] This concentration calibration curve differs from the above-mentioned <2-2. Concentration calibration curve of cyclohexanone oxime> only in the sublimable substance. The approximation formula is the same as the above-mentioned formula (1).

[0140] When using this concentration calibration curve, as described in <2-2. Concentration calibration curve of cyclohexanone oxime>, if the concentration decreases from concentration cn0 to concentration cn1, the target film thickness tg can be obtained, for example, by changing the rotation speed from 1000 rpm to 500 rpm.

[0141] The concentration calibration curve and the rotation speed calibration curve described above correspond to the "relationship" in the present invention.

[0142] <2-5. Rotational speed calibration curve for pinacoline oxime> Please refer to Figure 8. Figure 8 is a schematic diagram showing an example of a rotational speed calibration curve for pinacoline oxime.

[0143] This rotational speed calibration curve differs from the above-mentioned <2-3. Rotational speed calibration curve for cyclohexanone oxime> only in the sublimable substance. The approximation formula is the same as the above-mentioned formula (2).

[0144] When using this concentration calibration curve, as described in <2-3. Cyclohexanone oxime rotational speed calibration curve>, if the concentration of the solidified film-forming liquid decreases from 18.0 wt% (concentration cn0) to 15.4 wt% (concentration cn1), the target film thickness tg can be obtained, for example, by lowering the rotation speed from rv0 to rv1.

[0145] <3-1. Example of operation> 9 is a flowchart showing an example of substrate processing. Although not shown in this flowchart, the generation process executed by the solidified film forming liquid generation unit 23 is performed in parallel. During this process, the first sensor 31 detects the amount of solidified film forming liquid stored in the tank 25. The control unit 14 monitors the detection result of the first sensor 31. The control unit 14 starts and stops the solidified film forming liquid generation process based on the detection result of the first sensor 31.

[0146] In the following description, it is assumed that the chemical liquid processing step, the rinse liquid supplying step, and the substitute liquid supplying step have already been performed. These processing steps will now be briefly described.

[0147] Chemical treatment process The substrate W to be processed is held by the substrate holder 13. The rotation driver 18 rotates the substrate holder 13. The controller 14 supplies a chemical solution from the supply unit 19b to the substrate W. This removes, for example, a native oxide film from the substrate W.

[0148] Rinse liquid supply process The control unit 14 supplies the rinse liquid from the supply unit 19c to the substrate W. This removes, for example, the chemical liquid from the substrate W.

[0149] Substitution liquid supply process The control unit 14 supplies the substitute liquid from the supply unit 19d to the substrate W. The substitute liquid removes the rinse liquid from the substrate W. As a result, the rinse liquid on the substrate W is replaced with the substitute liquid.

[0150] Then, following the above-described substitute liquid supplying step, a solidified film forming liquid supplying step is carried out.

[0151] In this embodiment, a case will be described in which a solidified film is formed based on the "relationship of the rotation speed calibration curve" shown in Figures 6 and 8. That is, when a solidified film is formed using a solidified film forming solution of a predetermined concentration, the substrate W is rotated at a rotation speed corresponding to a target film thickness based on the rotation speed calibration curve of the predetermined concentration.

[0152] Step S1 A recipe is selected by an operator of the substrate processing apparatus 1. This step S1 may be performed before the chemical liquid processing step, the rinse liquid supply step, and the replacement liquid supply step described above are performed.

[0153] This allows a recipe including a target film thickness of the solidified film to be formed to be selected. The recipe is selected from an instruction unit (not shown) connected to the control unit 14. The instruction unit is composed of, for example, a keyboard, a pointing device, a display unit, etc. The recipe includes, for example, a target film thickness of the solidified film, a concentration of the solidified film forming solution, a first rotation speed, a maintenance time for the first rotation speed, a second rotation speed, a maintenance time for the second rotation speed, etc. The control unit 14 reads out an approximation formula from the memory unit 15. The approximation formula is Formula (1) or Formula (2) depending on the sublimable substance.

[0154] The control unit 14 operates the valves 26b and 27b to operate the solidified film formation liquid generating unit 23 so that the concentration of the solidified film formation liquid is as specified in the recipe. As a result, the solidified film formation liquid having the concentration specified in the recipe is generated in the tank 25. However, strictly speaking, the concentration may not be identical to the specified concentration, and some degree of variation may occur.

[0155] The target film thickness of the solidified film described above corresponds to the "target solidified film thickness" and the "target liquid film thickness" in the present invention.

[0156] Step S2 The concentration of the solidified film forming liquid generated in the solidified film forming liquid generation unit 23 is measured. Specifically, the valve 22a is opened and the pump 34 is operated, and the concentration of the solidified film forming liquid sent from the tank 25 into the pipe 33 is measured with the concentration meter 36.

[0157] Step S3 The control unit 14 receives the measured concentration from the concentration meter 36. The control unit 14 compares the predetermined concentration of the solidified film forming liquid in the recipe with the concentration received from the concentration meter 36. Depending on the result, the process branches.

[0158] Specifically, if the concentration received from the densitometer 36 has not deviated from the predetermined concentration, the process proceeds to step S6. On the other hand, if the concentration received from the densitometer 36 has deviated from the predetermined concentration, the process proceeds to step S7.

[0159] Here, the explanation will be given assuming that the comparison in step S3 shows no change.

[0160] Step S4 The control unit 14 rotates the rotation drive unit 18 at a first rotation speed according to the recipe, thereby rotating the substrate W at the first rotation speed for the maintenance time.

[0161] Step S5 The solidification film formation liquid is supplied from the supply unit 19a to the vicinity of the rotation center of the substrate W. The solidification film formation liquid supplied to the substrate W spreads from the vicinity of the center of the substrate W toward the periphery, coating the entire upper surface of the substrate W. The control unit 14 stops the pump 34 and closes the valve 22a. This stops the supply of the solidification film formation liquid from the supply unit 19a.

[0162] The first rotation speed when the solidified film forming liquid is supplied is lower than the second rotation speed described below. Therefore, compared to when the rotation speed is set to high speed from the beginning, scattering of the solidified film forming liquid can be suppressed, and consumption of the solidified film forming liquid can be suppressed.

[0163] The above-described steps S2 to S4 are performed within a relatively short time. Alternatively, steps S2 to S4 are performed at approximately the same timing. Alternatively, the solidified film forming liquid may be supplied to the substrate W after the substrate W starts to rotate at the first rotation speed so that step S4 is performed after step S5.

[0164] Steps S4 and S5 correspond to the "full surface coating step" in the present invention.

[0165] Step S6 The control unit 14 rotates the rotation drive unit 18 at a second rotation speed (e.g., 1000 rpm) according to the recipe. The substrate W is rotated at the second rotation speed for the maintenance time. This second rotation speed is higher than the first rotation speed. In other words, the first rotation speed is lower than the second rotation speed. As a result, part of the solidified film formation liquid that had covered the entire upper surface of the substrate W is shaken off by centrifugal force, and the thickness of the liquid film of the solidified film formation liquid on the upper surface of the substrate W is adjusted. When the maintenance time has elapsed, the control unit 14 stops the rotation drive unit 18. As a result, the substrate W comes to a standstill.

[0166] Reference is now made to Fig. 10. Fig. 10 is a schematic diagram showing the state of the substrate to which the solidifying film forming liquid has been supplied.

[0167] The substrate W has a pattern P formed on its upper surface W1. The pattern P has a protrusion W2 and a recess A. The protrusion W2 is a structure that forms part of the substrate W. The protrusion W2 is made of, for example, a silicon oxide film (SiO2), a silicon nitride film (SiN), or a polysilicon film. The protrusion W2 protrudes upward. The recess A is adjacent to the side of the protrusion W2. The recess A is a space. The recess A is open upward. The protrusion W2 corresponds to a wall that defines the recess A.

[0168] The solidified film formation liquid on the substrate W forms a liquid film H. The liquid film H of the solidified film formation liquid is located on the upper surface W1 of the substrate W. The liquid film H covers the upper surface W1 of the substrate W. The liquid film H has an upper surface H1. The upper surface H1 is located at a position higher than the entire pattern P. The entire pattern P is immersed in the liquid film H. The upper surface H1 is located at a position higher than the entire protrusion W2. The entire protrusion W2 is immersed in the liquid film H. The recess A is filled with the liquid film H. The entire recess A is filled only with the liquid film H. Note that the replacement liquid has already been removed from the upper surface W1 of the substrate W by the solidified film formation liquid. Therefore, the replacement liquid does not exist on the upper surface W1 of the substrate W. The replacement liquid does not remain in the recess A. The gas J is located above the liquid film H. The gas J is in contact with the upper surface H1. The upper surface H1 corresponds to the gas-liquid interface between the liquid film H and the gas J.

[0169] Step S7 The control unit 14 operates the rotation drive unit 18 to rotate the substrate W at a predetermined rotation speed. This causes the solvent to evaporate from the solidified film forming liquid on the substrate W. That is, the solvent is evaporated from the liquid film H. This causes the solvent to change into a gas. Here, the solvent has a relatively high vapor pressure. Therefore, the solvent evaporates easily.

[0170] Step S7 corresponds to the "solidified film forming step" in this invention. The rotation driving unit 18 corresponds to the "evaporation promoting unit" in this invention.

[0171] Reference is now made to Figure 11. Figure 11 is a schematic diagram showing the state of the substrate during the process of forming a solidified film.

[0172] As the solvent evaporates from the liquid film H, the liquid film H turns into a solidified film K.

[0173] Specifically, as the solvent evaporates, it leaves the liquid film H, and the amount of solvent contained in the liquid film H decreases. The concentration of the sublimable substance in the liquid film H increases, and the sublimable substance precipitates on the substrate W. That is, the sublimable substance changes from a solute in the solidified film-forming liquid that forms the liquid film H to a solid. As a result, a solidified film K is formed on the substrate W. The solidified film K is formed on the upper surface W1 of the substrate W. The solidified film K contains the sublimable substance. The solidified film K contains the sublimable substance in a solid phase. The solidified film K does not contain the solvent. The solidified film K is solid.

[0174] The liquid film H gradually decreases. The solidified film K gradually increases. First, the upper part of the liquid film H changes into the solidified film K. The remaining liquid film H is located below the solidified film K. The height position of the upper surface H1 of the liquid film H gradually decreases. The solidified film K covers the upper surface H1 of the liquid film H.

[0175] After the solidified film K covers the upper surface H1 of the liquid film H, the liquid film H does not come into contact with the gas J. When the liquid film H is covered by the solidified film K, the gas-liquid interface between the liquid film H and the gas J disappears. The liquid film H comes into contact with the solidified film K. The gas J comes into contact with the solidified film K. Therefore, in the solidified film formation process, the liquid film H decreases without exerting a significant force on the protruding portion W2. The solvent leaves the substrate W without exerting a significant force on the protruding portion W2.

[0176] Please refer to Fig. 12. Fig. 12 is a schematic diagram showing the state of the substrate during the process of forming a solidified film.

[0177] Eventually, the entire liquid film H disappears from the substrate W. No liquid is present on the upper surface W1 of the substrate W. At the end of the solidified film formation process, no liquid film H remains in the recess A. When the formation of the solidified film is complete, no liquid is present in the recess A. The recess A is filled with the solidified film K. The entire recess A is filled only with the solidified film K. The pattern P is in contact with the solidified film K. The pattern P is not in contact with the liquid. The protruding portion W2 is in contact with the solidified film K. The protruding portion W2 is not in contact with the liquid.

[0178] Step S8 In step S8, the solidified film K is sublimated. The control unit 14 supplies a first gas from the supply unit 19e toward the upper surface of the substrate W. This causes the solidified film K to sublimate. In other words, the solidified film K changes into a gas without passing through a liquid state. The sublimation of the solidified film K removes the solidified film K from the substrate W. Then, the supply unit 19e stops supplying the first gas to the solidified film K.

[0179] Step S8 corresponds to the "sublimation step" in this invention.

[0180] Here, reference is made to Figures 13 and 14. Figure 13 is a schematic diagram showing the state of the substrate during the sublimation of the solidified film, and Figure 14 is a schematic diagram showing the state of the substrate after the sublimation of the solidified film.

[0181] As shown in Figure 13, as the solidified film K sublimes, the solidified film K gradually decreases. As the solidified film K sublimes, gas J enters the recess A. When the solidified film K sublimes, it does not change into a liquid. Therefore, during the sublimation process, no liquid is present on the upper surface W1 of the substrate W. No liquid is present in the recess A. The pattern P does not come into contact with the liquid. The protrusion W2 does not come into contact with the liquid. The solidified film K leaves the upper surface W1 of the substrate W without exerting a significant force on the protrusion W2.

[0182] As shown in Figure 14, finally, the solidified film K disappears from the upper surface W1 of the substrate W. The recess A is filled with gas J. The entire recess A is filled only with gas J. No liquid exists on the upper surface W1 of the substrate W. The substrate W is completely dried.

[0183] Step S9 The control unit 14 operates the rotation drive unit 18 to stop the rotation of the substrate holder 13. The substrate W held by the substrate holder 13 stops rotating and comes to a standstill. The processing unit 11 finishes processing the substrate W.

[0184] Next, a processing example will be described in the case where, as a result of the comparison in step S3 described above, the concentration received from the concentration meter 36 has deviated from the predetermined concentration defined in the recipe.

[0185] Step S10 The control unit 14 adjusts the rotation speed based on the approximation formula. For example, in formula (2), the film thickness y of the solidified film is fixed at the target film thickness, and the concentration is set to the concentration received from the concentration meter 36. The coefficients y0, a, and b are determined from the concentration. In this way, the control unit 14 calculates the rotation speed x using formula (2). The control unit 14 operates the rotation driver 18 to achieve the calculated rotation speed x.

[0186] If the concentration deviates from the predetermined value, operating the rotation driver 18 at the rotation speed specified in the recipe will naturally result in a deviation from the target thickness of the solidified film. This may increase the collapse rate of the pattern P. Therefore, operations such as concentration adjustment are required to achieve the predetermined concentration, resulting in problems such as reduced throughput. However, according to this embodiment, as described above, the entire surface coating process rotates the substrate at a rotation speed adjusted to achieve the target solidified film thickness based on the relationship between the concentration, the target solidified film thickness, and the rotation speed. Therefore, even if the process is determined to be inappropriate because the concentration deviates from the predetermined value, the factors that cause the process to be inappropriate can be addressed by rotating the substrate at a rotation speed based on the above relationship. As a result, substrates can be processed without reducing throughput or increasing manufacturing costs.

[0187] Furthermore, in this embodiment, the fluctuation in concentration can be detected in step S2 before the solidified film forming liquid is supplied to the substrate, so that the solidified film forming rotation speed can be changed with ample time to spare. [Example]

[0188] A second embodiment of the present invention will be described below with reference to the drawings.

[0189] <4-1. Overview of substrate processing equipment> Fig. 15 is a diagram illustrating the configuration of a processing unit and a solidified film forming solution generating unit in a substrate processing apparatus according to Example 2. Fig. 16 is a block diagram of the substrate processing apparatus according to Example 2.

[0190] The overall configuration of the substrate processing apparatus 1 is the same as that of the first embodiment described above, and therefore illustrations and explanations thereof will be omitted.

[0191] In the solidified film forming liquid generating unit 23 in the second embodiment, the liquid sending section 32 does not include the concentration meter 36 .

[0192] The processing unit 11 in Example 2 is equipped with a concentration meter 51. Specifically, the housing 17 is equipped with the concentration meter 51 inside. The concentration meter 51 is a non-contact type. The concentration meter 51 detects the concentration of a sublimable substance in a solidified film forming solution. The concentration meter 51 is equipped with a light projector 53 and a light receiver 55. The light projector 53 and the light receiver 55 are arranged side by side in the vertical direction Z with the substrate W sandwiched therebetween. In a plan view, the light projector 53 and the light receiver 55 overlap. In a plan view, the light projector 53 and the light receiver 55 are arranged outward from the substrate holder 13 and inside the outer periphery of the substrate W. In other words, light from the concentration meter 51 is irradiated only onto the substrate W. In this example, the light projector 53 is arranged above the substrate W, and the light receiver 55 is arranged below the substrate W. The positional relationship between the light projector 53 and the light receiver 55 in the vertical direction Z may be reversed.

[0193] The light projector 53 emits, for example, light that passes through the substrate W. The light is, for example, infrared light. The light receiver 55 detects the intensity of the light. The densitometer 51 calculates the concentration of the solidified film formation liquid supplied to the upper surface of the substrate W based on the light projected by the light projector 53 and the intensity of the light detected by the light receiver 55. Since the intensity of light attenuated by the substrate W itself held by the substrate holder 13 is known, the concentration of the solidified film formation liquid on the upper surface of the substrate W can be calculated based on the degree of light attenuation. In other words, the higher the concentration of the sublimable substance in the solidified film formation liquid, the greater the attenuation on the upper surface of the substrate W, and the weaker the intensity of light received by the light receiver 53. A solidified film formation liquid of a known concentration is supplied to the substrate W in advance, and the light receiver 55 detects the intensity of the received light. Data obtained from the densitometer 51 by detecting the intensity of the received light while changing the concentration at a predetermined film thickness of the solidified film formation liquid is stored. This allows the concentration of the solidified film formation liquid on the upper surface of the substrate W to be detected based on the intensity of the light received by the light receiver 55.

[0194] The above-mentioned densitometer 51 corresponds to the "concentration detection unit" in the present invention. Note that instead of the transmission type densitometer 51, a reflection type densitometer that calculates the concentration based on light reflected by the upper surface of the substrate W may be used.

[0195] The solidified film formation liquid generation unit 23 does not measure the concentration of the solidified film formation liquid generated in the tank 25 by the liquid delivery unit 32. The solidified film formation liquid generation unit 23 measures the concentration of the solidified film formation liquid supplied to the upper surface of the substrate W from the nozzle 20 a.

[0196] <5-1. Example of operation> Please refer to Fig. 17. Fig. 17 is a flowchart showing an example of substrate processing.

[0197] Steps S21 to S23 are the same as steps S1, S4, and S5 in the first embodiment described above.

[0198] Step S24 The control unit 14 measures the concentration of the sublimable substance in the solidified film formation liquid supplied to the upper surface of the substrate W using the concentration meter 51.

[0199] Step S25 The control unit 14 branches the process depending on the concentration received from the concentration meter 51. Specifically, the process branches depending on the concentration of the sublimable substance in the solidified film forming liquid supplied from the nozzle 19a to the upper surface of the substrate W. If the concentration has not changed from the predetermined concentration, the process proceeds to step S26. If the concentration has changed from the predetermined concentration, the process proceeds to step S30.

[0200] Steps S26-S29 If the density has not changed from the predetermined density, the process is the same as steps S6 to S9 in the first embodiment described above, and therefore the description will be omitted.

[0201] Step S30 If the concentration measured on the upper surface of the substrate W deviates from the predetermined concentration, the solidified film formation liquid production unit 23 should be producing a solidified film formation liquid of the predetermined concentration. However, malfunctions may occur in the valves 26b and 27b, or in the sublimable substance supply source 28 or the solvent supply source 29. Furthermore, even if a solidified film formation liquid of the predetermined concentration is produced in the tank 25, there is a possibility that a malfunction in the piping 33 may cause the concentration to fluctuate during liquid transfer. Even in such cases, in this embodiment, a solidified film can be formed with a target thickness.

[0202] Specifically, the same process as step S10 in the first embodiment is performed. That is, the control unit 14 adjusts the rotation speed based on an approximation formula. For example, in formula (2), the film thickness y of the solidified film is fixed at the target film thickness, and the concentration is set to the concentration received from the concentration meter 51. The coefficients y0, a, and b are determined from the concentration. In this way, the control unit 14 calculates the rotation speed x using formula (2). The control unit 14 operates the rotation driver 18 to achieve the calculated rotation speed x.

[0203] According to this embodiment, the same effects as those of the first embodiment described above are achieved.

[0204] Furthermore, according to this embodiment, the concentration is detected on the upper surface of the substrate W, so that fluctuations in concentration can be detected even if there is an abnormality in the supply system of the solidified film forming liquid, such as the liquid delivery unit 32 or the piping 33. Therefore, it is possible to reliably prevent inappropriate processing due to fluctuations in concentration.

[0205] The present invention is not limited to the above-described embodiment, but can be modified as follows.

[0206] (1) In the above-described embodiments, the relationship between the concentration, the target solidified film thickness, and the rotation speed for forming the solidified film is described as an example. However, the relationship in the present invention is not limited to the solidified film.

[0207] That is, as shown in FIG. 4, when the film thickness is measured using a film thickness measurement method to determine the relationship, the film thickness at the time of measurement is that of a solidified film, but immediately before that measurement, it is a liquid film. Therefore, it can also be said that the film type at the time of film thickness measurement is a liquid film. Therefore, the relationship may be based on the concentration, the target liquid film thickness, and the liquid film formation rotation speed. In this case, the target film thickness corresponds to the "target liquid film thickness" in this invention, and the solidified film formation rotation speed corresponds to the "liquid film formation rotation speed" in this invention.

[0208] (2) In each of the above-described embodiments, a solidified film forming liquid is generated in the tank 25. However, the present invention is not limited to such a configuration. For example, a configuration may be adopted in which a sublimable substance and a solvent are mixed and supplied to the pipe 33. Alternatively, a solidified film forming liquid adjusted to a predetermined concentration may be directly supplied to the pipe 33.

[0209] (3) In the above-described embodiments, the processing is explained using the formula (2) as an example. However, the processing may be performed using the formula (1).

[0210] (4) In the above-described embodiments, the substrate processing apparatus 1 is described as having components such as the transport mechanisms 5 and 8, as shown in FIG. 1. However, the present invention is not limited to such a configuration. For example, the present invention may be a substrate processing apparatus having only the processing unit 11 and the control unit 14 (memory unit 15).

[0211] (5) In each of the above-described embodiments, the sublimation acceleration unit is constituted by the supply unit 19e and the nozzle 20e that discharge the first gas. However, the present invention is not limited to such a configuration. For example, the sublimation acceleration unit may be constituted by a means for accelerating sublimation by applying heat. Heating is preferably performed in a non-contact manner, such as by using a lamp heater or by supplying high-temperature gas. [Industrial Applicability]

[0212] As described above, the present invention is suitable for sublimation drying using a solidified film-forming liquid containing a sublimable substance. [Explanation of symbols]

[0213] 1... Substrate processing equipment W: Substrate 11... Processing unit 13... Board holding part 18... Rotation drive unit 19a-19e … Supply section 20a-20e ... nozzle 21a-21e ... Piping 22a-22e … Valve tu … film thickness gauge 23...Solidified film forming liquid generation unit 25 … tank 28 … Sublimable substance source 29 … Solvent Source 36,51 … Concentration meter y … Thickness of the solidified film tg…Target film thickness cn0,cn1 … Concentration rv0,rv1 … rotation speed

Claims

1. 1. A substrate processing method for drying a substrate on which a pattern is formed, comprising: a solidified film forming liquid supplying step of supplying a solidified film forming liquid containing a sublimable substance and a solvent onto a substrate; an entire surface coating step of rotating the substrate and spreading the solidified film forming liquid over the entire upper surface of the substrate to form a liquid film of the solidified film forming liquid; a solidified film forming step of evaporating the solvent from the liquid film of the solidified film forming liquid to precipitate the sublimable substance from the liquid film of the solidified film forming liquid, thereby forming a solidified film containing the sublimable substance over the entire upper surface of the substrate; a sublimation step of sublimating the solidified film to remove the solidified film from the substrate; Including, the entire surface coating step includes rotating the substrate at a solidified film formation rotation speed based on a relationship between a concentration of the sublimable substance in the solidified film formation liquid, a target solidified film thickness which is a desired film thickness and a solidified film formation rotation speed which is a rotation speed of the substrate for forming a solidified film having the target solidified film thickness when the concentration of the sublimable substance in the solidified film formation liquid is a predetermined concentration, and the relationship is expressed by an approximation formula that represents a change in the target solidified film thickness with respect to a change in either the concentration or the rotation speed for forming the solidified film, the rotation speed for forming the solidified film is determined based on the approximation formula, The substrate processing method, wherein the approximate formula is the following formula (1) or (2): (1) y = ax however, y: thickness of solidified film a: Slope that changes depending on the rotation speed for solidified film formation x: concentration of sublimable substance in solidified film forming liquid (2)y=y ０ +be －ｚ／ｃ however, y: thickness of solidified film y ０ : Coefficient that changes depending on the concentration of the sublimable substance in the solidified film forming liquid b: Coefficient that changes depending on the concentration of the sublimable substance in the solidified film-forming liquid e: Napier's number z: rotation speed for forming solidified film c: Coefficient that changes depending on the concentration of the sublimable substance in the solidified film-forming liquid

2. 1. A substrate processing method for drying a substrate on which a pattern is formed, comprising: a solidified film forming liquid supplying step of supplying a solidified film forming liquid containing a sublimable substance and a solvent onto a substrate; an entire surface coating step of rotating the substrate and spreading the solidified film forming liquid over the entire upper surface of the substrate to form a liquid film of the solidified film forming liquid; a solidified film forming step of evaporating the solvent from the liquid film of the solidified film forming liquid to precipitate the sublimable substance from the liquid film of the solidified film forming liquid, thereby forming a solidified film containing the sublimable substance over the entire upper surface of the substrate; a sublimation step of sublimating the solidified film to remove the solidified film from the substrate; Including, The entire surface coating step includes rotating the substrate at a liquid film formation rotation speed based on a relationship between a concentration of the sublimable substance in the solidified film formation liquid, a target liquid film thickness which is a desired film thickness, and a liquid film formation rotation speed which is a rotation speed of the substrate for forming a liquid film having the target liquid film thickness when the concentration of the sublimable substance in the solidified film formation liquid is a predetermined concentration; the relationship is expressed by an approximation formula that represents a change in the target liquid film thickness with respect to a change in either the concentration or the liquid film formation rotation speed, the liquid film formation rotation speed is determined based on the approximation formula, The substrate processing method, wherein the approximate formula is the following formula (1) or (2): (1) y = ax however, y: thickness of solidified film a: Slope that changes depending on the rotation speed for solidified film formation x: concentration of sublimable substance in solidified film forming liquid (2)y=y ０ +be －ｚ／ｃ however, y: thickness of solidified film y ０ : Coefficient that changes depending on the concentration of the sublimable substance in the solidified film forming liquid b: Coefficient that changes depending on the concentration of the sublimable substance in the solidified film-forming liquid e: Napier's number z: rotation speed for forming solidified film c: Coefficient that changes depending on the concentration of the sublimable substance in the solidified film-forming liquid

3. 2. The substrate processing method according to claim 1, and determining the solidified film formation rotation speed in accordance with the concentration fluctuation based on the relationship when the concentration of the sublimable substance in the solidified film formation solution fluctuates from the predetermined concentration.

4. 4. The substrate processing method according to claim 1, further comprising: a substrate processing method characterized in that the entire surface coating step includes rotating the substrate at a rotation speed lower than the solidification film formation rotation speed so as to spread the solidification film formation liquid over the entire upper surface of the substrate before rotating the substrate at the solidification film formation rotation speed.

5. 5. The substrate processing method according to claim 1, a step of measuring the concentration of the solidifying film forming liquid before the solidifying film forming liquid supply step;

6. 6. The substrate processing method according to claim 1, a step of measuring the concentration of the solidifying film forming solution on the upper surface of the substrate in the solidifying film forming solution supplying step;

7. a rotation holding unit that holds a substrate on which a pattern is formed in a horizontal position and rotates the substrate within a horizontal plane; a solidified film forming liquid supply unit that supplies a solidified film forming liquid containing a sublimable substance and a solvent onto the upper surface of the substrate held by the rotation holder; Equipped with a substrate processing apparatus that rotates the spin holder to rotate the substrate, thereby spreading the solidified film forming liquid supplied from the solidified film forming liquid supply unit onto the upper surface of the substrate, thereby forming a liquid film of the solidified film forming liquid, evaporating the solvent from the liquid film of the solidified film forming liquid to precipitate the sublimable substance from the liquid film of the solidified film forming liquid, thereby forming a solidified film containing the sublimable substance over the entire upper surface of the substrate, and sublimating the solidified film to remove it from the substrate, thereby drying the substrate; a storage unit that stores in advance the relationship between a concentration of the sublimable substance in the solidified film forming liquid, a target solidified film thickness that is a desired film thickness of the solidified film formed on the entire upper surface of the substrate by precipitating the sublimable substance from the liquid film of the solidified film forming liquid, and a solidified film formation rotation speed that is a rotation speed of the substrate for forming a solidified film with the target solidified film thickness when the concentration of the sublimable substance in the solidified film forming liquid is a predetermined concentration; a control unit that controls the rotation holding unit so that the substrate rotates at the solidified film formation rotation speed based on the relationship stored in the storage unit; Furthermore, the relationship stored in the storage unit is expressed by an approximation formula that represents a change in the target solidified film thickness with respect to a change in either the concentration or the solidified film formation rotation speed; The control unit reading the approximation formula from the storage unit, and determining the solidified film formation rotation speed based on the approximation formula; The substrate processing apparatus wherein the approximate formula is the following formula (1) or (2): (1) y = ax however, y: thickness of solidified film a: Slope that changes depending on the rotation speed for solidified film formation x: concentration of sublimable substance in solidified film forming liquid (2)y=y ０ +be －ｚ／ｃ however, y: thickness of solidified film y0: Coefficient that changes depending on the concentration of the sublimable substance in the solidified film-forming liquid b: Coefficient that changes depending on the concentration of the sublimable substance in the solidified film-forming liquid e: Napier's number z: rotation speed for forming solidified film c: Coefficient that changes depending on the concentration of the sublimable substance in the solidified film-forming liquid

8. a rotation holding unit that holds a substrate on which a pattern is formed in a horizontal position and rotates the substrate within a horizontal plane; a solidified film forming liquid supply unit that supplies a solidified film forming liquid containing a sublimable substance and a solvent onto the upper surface of the substrate held by the rotation holder; Equipped with a substrate processing apparatus that rotates the spin holder to rotate the substrate, thereby spreading the solidified film forming liquid supplied from the solidified film forming liquid supply unit onto the upper surface of the substrate, thereby forming a liquid film of the solidified film forming liquid, evaporating the solvent from the liquid film of the solidified film forming liquid to precipitate the sublimable substance from the liquid film of the solidified film forming liquid, thereby forming a solidified film containing the sublimable substance over the entire upper surface of the substrate, and sublimating the solidified film to remove it from the substrate, thereby drying the substrate; a storage unit that stores in advance the relationship between the concentration of the sublimable substance in the solidified film forming liquid, a target liquid film thickness that is a desired film thickness of the liquid film of the solidified film forming liquid formed on the upper surface of the substrate, and a liquid film formation rotation speed that is a rotation speed of the substrate for forming a liquid film of the target liquid film thickness when the concentration of the sublimable substance in the solidified film forming liquid is a predetermined concentration; a control unit that controls the rotation holding unit so that the substrate rotates at the liquid film formation rotation speed based on the relationship stored in the storage unit; Furthermore, the relationship stored in the storage unit is expressed by an approximation formula that represents a change in the target liquid film thickness with respect to a change in either the concentration or the liquid film formation rotation speed, The control unit reading the approximation formula from the storage unit, and determining the liquid film formation rotation speed based on the approximation formula; The substrate processing apparatus wherein the approximate formula is the following formula (1) or (2): (1) y = ax however, y: thickness of solidified film a: Slope that changes depending on the rotation speed for solidified film formation x: concentration of sublimable substance in solidified film forming liquid (2)y=y ０ +be －ｚ／ｃ however, y: thickness of solidified film y ０ : Coefficient that changes depending on the concentration of the sublimable substance in the solidified film forming liquid b: Coefficient that changes depending on the concentration of the sublimable substance in the solidified film-forming liquid e: Napier's number z: rotation speed for forming solidified film c: Coefficient that changes depending on the concentration of the sublimable substance in the solidified film-forming liquid

9. 8. The substrate processing apparatus according to claim 7, The control unit controls the rotation holding unit to rotate the substrate at a rotation speed lower than the solidification film formation rotation speed in order to spread the solidification film formation liquid over the entire upper surface of the substrate before controlling the rotation holding unit to rotate the substrate at the solidification film formation rotation speed.

10. 10. The substrate processing apparatus according to claim 7, the substrate processing apparatus further includes a concentration detection unit that detects a concentration of the sublimable substance in the solidified film formation liquid, and when the concentration of the sublimable substance in the solidified film forming solution varies from the predetermined concentration based on the detection result of the concentration detection unit, the control unit determines the solidified film forming rotation speed in accordance with the variation in concentration based on the relationship stored in the memory unit.

11. 11. The substrate processing apparatus according to claim 10, The substrate processing apparatus is characterized in that the concentration detection unit detects the concentration of the sublimable substance in the solidified film formation liquid present in the solidified film formation liquid supply unit.

12. 12. The substrate processing apparatus according to claim 10, The substrate processing apparatus is characterized in that the concentration detection unit detects the concentration of the sublimable substance in the solidified film formation liquid supplied to the upper surface of the substrate held by the rotation holding unit.

13. 13. The substrate processing apparatus according to claim 7, the substrate processing apparatus further includes an evaporation promoting unit that promotes evaporation of the solvent from the liquid film of the solidified film forming liquid, The substrate processing apparatus, wherein the control unit controls the evaporation promotion unit so as to promote evaporation of the solvent from the liquid film.

14. 14. The substrate processing apparatus according to claim 7, the substrate processing apparatus further includes a sublimation promoter that promotes sublimation of the solidified film from the substrate; The substrate processing apparatus, wherein the control unit controls the sublimation promoting unit so as to promote sublimation of the solidified film from the substrate.

15. The substrate processing method according to claim 2, a substrate processing method characterized in that, when the concentration of the sublimable substance in the solidified film forming liquid fluctuates from the predetermined concentration, the liquid film formation rotation speed is determined in accordance with the fluctuation in concentration based on the relationship.

16. The substrate processing method according to claim 2 or claim 15, The substrate processing method is characterized in that the entire surface coating step includes rotating the substrate at a rotation speed lower than the liquid film formation rotation speed in order to spread the solidified film forming liquid over the entire upper surface of the substrate before rotating the substrate at the liquid film formation rotation speed.

17. The substrate processing apparatus according to claim 8, The control unit controls the rotation holding unit to rotate the substrate at a rotation speed lower than the liquid film formation rotation speed in order to spread the solidification film forming liquid over the entire upper surface of the substrate before controlling the rotation holding unit to rotate the substrate at the liquid film formation rotation speed.

18. The substrate processing apparatus according to claim 8 or claim 17, the substrate processing apparatus further includes a concentration detection unit that detects a concentration of the sublimable substance in the solidified film formation liquid, When the concentration of the sublimable substance in the solidified film forming liquid fluctuates from the predetermined concentration based on the detection result of the concentration detection unit, the control unit determines the liquid film formation rotation speed in accordance with the fluctuation in concentration based on the relationship stored in the memory unit.

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