Substrate processing method, substrate processing apparatus, and processing liquid

Abstract

To provide a substrate processing method, a substrate processing apparatus, and a process liquid with which a substrate can be appropriately dried.SOLUTION: The present invention relates to a substrate processing method, a substrate processing apparatus, and a process liquid. The substrate processing method includes a process liquid supply step, a solidified film forming step, and a sublimation step. In the process liquid supply step, the process liquid is supplied to a substrate. The process liquid includes a sublimable material and a solvent. In the solidified film forming step, the solvent evaporates from the process liquid on the substrate. In the solidified film forming step, a solidified film is formed on the substrate. The solidified film includes the sublimable material. In the sublimation step, the solidified film sublimes. The sublimation of the solidified film dries the substrate. Here, the sublimable material is 4-nitrotoluene.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] This invention relates to a substrate processing method, a substrate processing apparatus, and a processing liquid. The substrate is, for example, a semiconductor wafer, a substrate for a liquid crystal display, a substrate for an organic EL (Electroluminescence), a substrate for an FPD (Flat Panel Display), a substrate for an optical display, a substrate for a magnetic disk, a substrate for an optical disk, a substrate for a magneto-optical disk, a substrate for a photomask, or a substrate for a solar cell.

Background Art

[0002] Patent Document 1 discloses a substrate processing method for drying a substrate. Specifically, the substrate processing method of Patent Document 1 includes a processing liquid supply step, a solidified film formation step, and a sublimation step. In the processing liquid supply step, the processing liquid is supplied to the substrate. The processing liquid contains a solvent and a sublimable substance. The sublimable substance is cyclohexanone oxime. In the solidified film formation step, the solvent evaporates, and a solidified film is formed on the substrate. The solidified film contains cyclohexanone oxime. In the sublimation step, the solidified film sublimates. The solidified film changes to a gas without passing through a liquid state. According to the substrate processing method of Patent Document 1, the substrate can be dried appropriately.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Even with conventional substrate processing methods, there are cases where the substrate cannot be dried appropriately. For example, even with conventional substrate processing methods, there are cases where the pattern formed on the substrate collapses. For example, when the pattern is fine, conventional substrate processing methods may not be able to sufficiently suppress the collapse of the pattern.

[0005] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a substrate processing method, a substrate processing apparatus, and a processing liquid that can properly dry a substrate. [Means for solving the problem]

[0006] In order to achieve the above object, the present invention has the following configuration: That is, the present invention is a substrate processing method for processing a substrate on which a pattern is formed, comprising: a processing liquid supplying step of supplying a processing liquid containing a sublimable substance and a solvent to the substrate, a solidified film forming step of evaporating the solvent from the processing liquid on the substrate to form a solidified film containing the sublimable substance on the substrate, and a sublimation step of sublimating the solidified film, wherein the sublimable substance is 4-nitrotoluene.

[0007] The substrate processing method is for processing a substrate on which a pattern is formed. The substrate processing method includes a processing liquid supplying step, a solidified film forming step, and a sublimation step. In the processing liquid supplying step, a processing liquid is supplied to the substrate. The processing liquid includes a sublimable substance and a solvent. In the solidified film forming step, the solvent evaporates from the processing liquid on the substrate. In the solidified film forming step, a solidified film is formed on the substrate. The solidified film includes a sublimable substance. In the sublimation step, the solidified film sublimes. The substrate is dried by sublimation of the solidified film. Here, the sublimable substance is 4-nitrotoluene. That is, the processing liquid includes 4-nitrotoluene and the solvent. Therefore, the solidified film includes 4-nitrotoluene. Therefore, the substrate is properly dried. Specifically, the substrate is dried while the pattern formed on the substrate is properly protected.

[0008] As described above, according to the present substrate processing method, the substrate is properly dried.

[0009] In the above-described substrate processing method, the solvent is preferably isopropyl alcohol. Isopropyl alcohol dissolves 4-nitrotoluene well. Furthermore, isopropyl alcohol evaporates more easily than 4-nitrotoluene. Therefore, the substrate is more appropriately dried.

[0010] The present invention is a substrate processing apparatus comprising: a substrate holding unit that holds a substrate; and a processing liquid supply unit that supplies a processing liquid containing a sublimable substance and a solvent to the substrate held by the substrate holding unit, wherein the sublimable substance is 4-nitrotoluene.

[0011] The substrate processing apparatus includes a substrate holding unit and a processing liquid supply unit. The substrate holding unit holds a substrate. The processing liquid supply unit supplies the processing liquid to the substrate held by the substrate holding unit. The processing liquid contains a sublimable substance and a solvent. The sublimable substance is 4-nitrotoluene. Therefore, when the processing liquid is supplied to the substrate, the solvent evaporates suitably from the processing liquid on the substrate. Therefore, a solidified film is suitably formed on the substrate. The solidified film contains 4-nitrotoluene. Therefore, the solidified film sublimes suitably. The substrate is dried suitably by the sublimation of the solidified film. As described above, according to this substrate processing apparatus, the substrate is dried suitably.

[0012] In the substrate processing apparatus described above, the solvent is preferably isopropyl alcohol. Isopropyl alcohol dissolves 4-nitrotoluene well. Isopropyl alcohol evaporates more easily than 4-nitrotoluene. Therefore, the substrate is dried more appropriately.

[0013] The present invention provides a treatment liquid used for drying a substrate on which a pattern has been formed, the treatment liquid including a sublimable substance and a solvent, wherein the sublimable substance is 4-nitrotoluene.

[0014] The treatment liquid is used to dry a substrate on which a pattern has been formed. Specifically, the treatment liquid is a drying auxiliary liquid. The treatment liquid contains a sublimable substance and a solvent. The sublimable substance is 4-nitrotoluene. Therefore, the treatment liquid is useful for drying a substrate. Specifically, by using the treatment liquid, the substrate is dried while the pattern formed on the substrate is suitably protected. As described above, the substrate is dried appropriately using the treatment liquid.

[0015] In the above-described treatment liquid, the solvent is preferably isopropyl alcohol. Isopropyl alcohol dissolves 4-nitrotoluene well. Furthermore, isopropyl alcohol evaporates more easily than 4-nitrotoluene. Therefore, the treatment liquid is more useful for drying a substrate. The substrate can be dried more appropriately using the treatment liquid. [Effects of the Invention]

[0016] According to the substrate processing method, substrate processing apparatus, and processing solution of the present invention, the substrate is dried appropriately. [Brief description of the drawings]

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

[0018] Hereinafter, with reference to the drawings, a substrate processing method, a substrate processing apparatus, and a processing liquid of the present invention will be described.

[0019] <1. Substrate> The substrate W is, for example, a semiconductor wafer, a substrate for a liquid crystal display, a substrate for an organic EL (Electroluminescence), a substrate for an FPD (Flat Panel Display), a substrate for an optical display, a substrate for a magnetic disk, a substrate for an optical disk, a substrate for a magneto-optical disk, a substrate for a photomask, or a substrate for a solar cell. The substrate W has a thin flat plate shape. The substrate W has a substantially circular shape in plan view.

[0020] FIG. 1 is a diagram schematically showing a part of the substrate W. The substrate W has a pattern P. The pattern P is formed on the surface of the substrate W.

[0021] The pattern P has, for example, a concavo-convex shape. The pattern P has, for example, a convex portion W1 and a concave portion A. The convex portion W1 is a part of the substrate W. The convex portion W1 is a structure. The convex portion W1 is composed of, for example, at least one of a silicon oxide film (SiO2), a silicon nitride film (SiN), and a polysilicon film. The convex portion W1 protrudes upward from the surface of the substrate W, for example. The concave portion A is adjacent to the side of the convex portion W1. The concave portion A is a space. The concave portion A is open upward, for example. The convex portion W1 corresponds to a wall that partitions the concave portion A.

[0022] <2. Processing Liquid (Drying Aid Liquid)> In this specification, the processing liquid used for drying the substrate W is simply referred to as "processing liquid". The processing liquid has a function of assisting in drying the substrate W. The processing liquid can be referred to as a drying aid liquid.

[0023] The processing liquid contains a sublimable substance. The sublimable substance has sublimability. "Sublimability" is a property in which a single substance, compound, or mixture undergoes a phase transition from a solid to a gas, or from a gas to a solid, without passing through a liquid phase.

[0024] The sublimable substance contains 4-nitrotoluene. The sublimable substance contains, for example, only 4-nitrotoluene. 4-Nitrotoluene is represented by the following chemical formula (1).

[0025] [Chemical formula]

[0026] The treatment liquid contains a solvent. The solvent dissolves the sublimable substance. The sublimable substance in the treatment liquid is dissolved in the solvent. That is, the treatment liquid contains the solvent and the sublimable substance dissolved in the solvent. The sublimable substance corresponds to the solute of the treatment liquid.

[0027] The solvent has a relatively high vapor pressure at normal temperature. For example, it is preferable that the vapor pressure of the solvent at normal temperature is higher than the vapor pressure of the sublimable substance at normal temperature.

[0028] Here, normal temperature includes room temperature. Normal temperature is, for example, a temperature within the range of 5°C or higher and 35°C or lower. Normal temperature is, for example, a temperature within the range of 10°C or higher and 30°C or lower. Normal temperature is, for example, a temperature within the range of 20°C or higher and 25°C or lower.

[0029] The volume of the sublimable substance contained in the treatment liquid is smaller than the volume of the solvent contained in the treatment liquid. For example, it is preferable that the volume ratio RV of the treatment liquid is 1 [Vol%] or more and 20 [Vol%] or less. Here, the volume ratio RV of the treatment liquid is the ratio of the volume of the sublimable substance contained in the treatment liquid to the volume of the solvent contained in the treatment liquid. In other words, the volume ratio RV of the treatment liquid is defined by the following formula. RV = (volume of sublimable substance contained in the treatment liquid) / (volume of solvent contained in the treatment liquid) * 100 [Vol%]

[0030] The solvent is, for example, an organic solvent. The solvent is, for example, alcohol.

[0031] The solvent may include, for example, isopropyl alcohol (IPA). The solvent may include, for example, only isopropyl alcohol (IPA). The vapor pressure of isopropyl alcohol at room temperature is higher than the vapor pressure of 4-nitrotoluene at room temperature.

[0032] The processing liquid is, for example, composed of only a sublimable substance and a solvent.

[0033] The treatment liquid consists, for example, of only 4-nitrotoluene and isopropyl alcohol.

[0034] <3. Overview of substrate processing equipment> 2 is a plan view showing the inside of the substrate processing apparatus 1 according to the embodiment. The substrate processing apparatus 1 performs processing on the substrate W. The processing in the substrate processing apparatus 1 includes a drying process.

[0035] 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. The indexer unit 3 retrieves the substrates W from the processing block 7.

[0036] 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.

[0037] The indexer unit 3 includes a plurality (for example, four) of carrier placement units 4. Each carrier placement unit 4 places one carrier C. The carrier C houses a plurality of substrates W. The carrier C is, for example, a FOUP (Front Opening Unified Pod), a SMIF (Standard Mechanical Interface), or an OC (Open Cassette).

[0038] The indexer unit 3 includes a transfer mechanism 5. The transfer mechanism 5 is disposed behind the carrier placement unit 4. The transfer mechanism 5 transfers the substrate W. The transfer mechanism 5 can access the carrier C placed on the carrier placement unit 4. The transfer mechanism 5 includes a hand 5a and a hand drive unit 5b. The hand 5a supports the substrate W. The hand drive unit 5b is connected to the hand 5a. The hand drive unit 5b moves the hand 5a. The hand drive 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 drive unit 5b rotates the hand 5a, for example, within a horizontal plane.

[0039] The processing block 7 includes a transfer mechanism 8. The transfer mechanism 8 transfers the substrate W. The transfer mechanism 8 and the transfer mechanism 5 can transfer the substrate W to each other. The transfer mechanism 8 includes a hand 8a and a hand drive unit 8b. The hand 8a supports the substrate W. The hand drive unit 8b is connected to the hand 8a. The hand drive unit 8b moves the hand 8a. The hand drive unit 8b moves the hand 8a, for example, in the front-rear direction X, the width direction Y, and the vertical direction Z. The hand drive unit 8b rotates the hand 8a, for example, within a horizontal plane.

[0040] The processing block 7 includes a plurality of processing units 11. The processing units 11 are disposed on the sides of the transfer mechanism 8. Each processing unit 11 performs processing on the substrate W.

[0041] The processing unit 11 includes a substrate holding unit 13. The substrate holding unit 13 holds the substrate W.

[0042] The transfer mechanism 8 can access each processing unit 11. The transfer mechanism 8 can deliver the substrate W to the substrate holding unit 13. The transfer mechanism 8 can pick up the substrate W from the substrate holding unit 13.

[0043] FIG. 3 is a control block diagram of the substrate processing apparatus 1. The substrate processing apparatus 1 includes a control unit 10. The control unit 10 can communicate with the transfer mechanisms 5 and 8 and the processing unit 11. The control unit 10 controls the transfer mechanisms 5 and 8 and the processing unit 11.

[0044] The control unit 10 is realized by a central processing unit (CPU) that executes various processes, a RAM (Random-Access Memory) that serves as a work area for arithmetic processing, a storage medium such as a fixed disk, and the like. The control unit 10 has various kinds of information stored in advance in the storage medium. The information possessed by the control unit 10 is, for example, transfer condition information for controlling the transfer mechanisms 5 and 8. The information possessed by the control unit 10 is, for example, processing condition information for controlling the processing unit 11. The processing condition information is also called a processing recipe.

[0045] An operation example of the substrate processing apparatus 1 will be briefly described.

[0046] The indexer unit 3 supplies the substrate W to the processing block 7. Specifically, the transfer mechanism 5 delivers the substrate W from the carrier C to the transfer mechanism 8 of the processing block 7.

[0047] The transfer mechanism 8 distributes the substrate W to the processing unit 11. Specifically, the transfer mechanism 8 transports the substrate W from the transfer mechanism 5 to the substrate holding unit 13 of each processing unit 11.

[0048] The processing unit 11 processes the substrate W held by the substrate holding unit 13. The processing unit 11 performs, for example, a drying process on the substrate W.

[0049] After the processing units 11 have processed the substrates W, the transport mechanism 8 collects the substrates W from each processing unit 11. Specifically, the transport mechanism 8 receives the substrates W from each substrate holder 13. Then, the transport mechanism 8 hands over the substrates W to the transport mechanism 5.

[0050] The indexer unit 3 retrieves the substrate W from the processing block 7. Specifically, the transport mechanism 5 transports the substrate W from the transport mechanism 8 to the carrier C.

[0051] <4. Configuration of processing unit 11> 4 is a diagram showing the configuration of the processing units 11. Each processing unit 11 has the same structure. The processing units 11 are classified as single-wafer processing units. That is, each processing unit 11 processes only one substrate W at a time.

[0052] The processing unit 11 includes a housing 12. The housing 12 has a substantially box shape. The substrate W is processed inside the housing 12.

[0053] The inside of the housing 12 is kept at room temperature, so the substrate W is processed in a room temperature environment.

[0054] The inside of the housing 12 is kept at atmospheric pressure, so that the substrate W is processed in an atmospheric pressure environment.

[0055] Here, atmospheric pressure includes standard atmospheric pressure (1 atmosphere, 101,325 Pa). Normal pressure is, for example, a pressure in the range of 0.7 atmospheres or more and 1.3 atmospheres or less. In this specification, pressure is indicated as absolute pressure based on absolute vacuum.

[0056] The above-described substrate holding unit 13 is installed inside the housing 12. The substrate holding unit 13 holds one substrate W. The substrate holding unit 13 holds the substrate W in a substantially horizontal position.

[0057] The substrate holding part 13 is positioned below the substrate W held by the substrate holding part 13. The substrate holding part 13 comes into contact with at least one of the lower surface of the substrate W and the peripheral edge of the substrate W. The substrate holding part 13 does not come into contact with the upper surface of the substrate W.

[0058] The processing unit 11 is equipped with a rotational drive unit 14. At least a portion of the rotational drive unit 14 is installed inside the housing 12. The rotational drive unit 14 is connected to the substrate holding unit 13. The rotational drive unit 14 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 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.

[0059] The processing unit 11 includes a supply unit 15. The supply unit 15 supplies a liquid or a gas to the substrate W held by the substrate holding unit 13. Specifically, the supply unit 15 supplies a liquid or a gas to the upper surface of the substrate W held by the substrate holding unit 13.

[0060] The supply unit 15 includes a first supply unit 15a, a second supply unit 15b, a third supply unit 15c, a fourth supply unit 15d, and a fifth supply unit 15e. The first supply unit 15a supplies a processing liquid. The second supply unit 15b supplies a chemical liquid. The third supply unit 15c supplies a rinse liquid. The fourth supply unit 15d supplies a replacement liquid. The fifth supply unit 15e supplies a drying gas.

[0061] The first supply unit 15a is an example of the processing liquid supply unit defined in the present invention.

[0062] As described above, the inside of the housing 12 is at room temperature and pressure. Therefore, the processing liquid is used in an environment at room temperature. The processing liquid is used in an environment at normal pressure.

[0063] The chemical liquid supplied by the second supply unit 15b is, for example, an etching liquid, which includes, for example, at least one of hydrofluoric acid (HF) and buffered hydrofluoric acid (BHF).

[0064] The rinse liquid supplied by the third supply unit 15c is, for example, deionized water (DIW).

[0065] The substitute liquid supplied by the fourth supply unit 15d is, for example, an organic solvent, or isopropyl alcohol (IPA).

[0066] The dry gas supplied by the fifth supply unit 15e is, for example, at least one of air and an inert gas. The air is, for example, compressed air. The inert gas is, for example, nitrogen gas. The dry gas preferably has a dew point lower than room temperature.

[0067] The first supply unit 15a includes a nozzle 16a. Similarly, the second to fifth supply units 15b-15e include nozzles 16b-16e, respectively. The nozzles 16a-16e are installed inside the housing 12. The nozzle 16a discharges a processing liquid. The nozzle 16b discharges a chemical liquid. The nozzle 16c discharges a rinse liquid. The nozzle 16d discharges a substitute liquid. The nozzle 16e discharges a drying gas.

[0068] The first supply unit 15a includes a pipe 17a and a valve 18a. The pipe 17a is connected to a nozzle 16a. The valve 18a is provided on the pipe 17a. When the valve 18a is open, the nozzle 16a discharges the processing liquid. When the valve 18a is closed, the nozzle 16a does not discharge the processing liquid. Similarly, the second to fifth supply units 15b-15e include pipes 17b-17e and valves 18b-18e, respectively. The pipes 17b-17e are connected to the nozzles 16b-16e, respectively. The valves 18b-18e are provided on the pipes 17b-17e, respectively. The valves 18b-18e control the discharge of the chemical liquid, the rinse liquid, the replacement liquid, and the drying gas, respectively.

[0069] At least a portion of pipe 17a may be provided outside of housing 12. Pipes 17b-17e may be arranged in the same manner as pipe 17a. Valve 18a may be provided outside of housing 12. Valves 18b-18e may be arranged in the same manner as valve 18a.

[0070] The substrate processing apparatus 1 includes a first supply source 19a. The first supply source 19a is connected to a first supply unit 15a. The first supply source 19a is connected to, for example, a pipe 17a. The first supply source 19a supplies the processing liquid to the first supply unit 15a.

[0071] The second supply unit 15b is connected to the second supply source 19b. The second supply source 19b is connected to, for example, the pipe 17b. The second supply source 19b supplies the chemical solution to the second supply unit 15b. Similarly, the third to fifth supply units 15c-15e are connected to the third to fifth supply sources 19c-19e, respectively. The third to fifth supply sources 19c-19e are connected to, for example, the pipes 17c-17e, respectively. The third supply source 19c supplies the rinse liquid to the third supply unit 15c. The fourth supply source 19d supplies the replacement liquid to the fourth supply unit 15d. The fifth supply source 19e supplies the drying gas to the fifth supply unit 15e.

[0072] The first supply source 19a is provided outside the housing 12. Similarly, the second to fifth supply sources 19b to 19e are each provided outside the housing 12.

[0073] The first supply source 19a may supply the processing liquid to multiple processing units 11. Alternatively, the first supply source 19a may supply the processing liquid to only one processing unit 11. The same applies to the second to fifth supply sources 19b to 19e.

[0074] The second supply source 19b may be a component of the substrate processing apparatus 1. For example, the second supply source 19b may be a chemical tank provided in the substrate processing apparatus 1. Alternatively, the second supply source 19b may not be a component of the substrate processing apparatus 1. For example, the second supply source 19b may be a utility facility installed outside the substrate processing apparatus 1. Similarly, the third to fifth supply sources 19c-19e may each be a component of the substrate processing apparatus 1. Alternatively, the third to fifth supply sources 19c-19e may each be a component of the substrate processing apparatus 1.

[0075] The processing unit 11 may further include a cup (not shown). The cup is installed inside the housing 12. The cup is disposed around the substrate holding portion 13. The cup receives the liquid scattered from the substrate W held by the substrate holding portion 13.

[0076] Referring to FIG. 3, the control unit 10 controls the rotational drive unit 14. The control unit 10 controls the supply unit 15. The control unit 10 controls the valves 18a - 18e.

[0077] <5. Configuration of the First Supply Source 19a> Referring to FIG. 4, the first supply source 19a further generates a processing liquid.

[0078] An example of the configuration of the first supply source 19a is illustrated. The first supply source 19a is divided into a generation unit 21 and a pumping unit 31. The generation unit 21 generates a processing liquid. The pumping unit 31 sends the processing liquid to the first supply unit 15a.

[0079] The generation unit 21 includes a tank 22 and supply parts 23a, 23b. The supply part 23a supplies a sublimable substance to the tank 22. The supply part 23b supplies a solvent to the tank 22. The sublimable substance and the solvent are mixed in the tank 22. The sublimable substance and the solvent become the processing liquid g in the tank 22.

[0080] The tank 22 is installed under a normal temperature environment. The tank 22 is installed under a normal pressure environment. Therefore, the processing liquid g is generated under a normal temperature environment. The processing liquid g is generated under a normal pressure environment.

[0081] Furthermore, the generation unit 21 stores the processing liquid g. Specifically, the processing liquid g is stored in the tank 22. The processing liquid g is stored under a normal temperature environment. The processing liquid g is stored under a normal pressure environment.

[0082] The supply unit 23a includes, for example, a pipe 24a and a valve 25a. The pipe 24a is communicatively connected to the tank 22. The valve 25a is provided in the pipe 24a. When the valve 25a opens, the supply unit 23a supplies the sublimable substance to the tank 22. When the valve 25a closes, the supply unit 23a does not supply the sublimable substance to the tank 22. Similarly, the supply unit 23b includes a pipe 24b and a valve 25b. The pipe 24b is communicatively connected to the tank 22. The valve 25b is provided in the pipe 24b. The valve 25b controls the supply of the solvent to the tank 22.

[0083] Furthermore, the amount of the sublimable substance in the tank 22 is controlled by the valve 25a. The amount of the solvent in the tank 22 is controlled by the valve 25b. Therefore, the volume ratio RV of the processing liquid g in the tank 22 is controlled by the valves 25a and 25b.

[0084] Each of the valves 25a and 25b may include, for example, a flow rate regulating valve. Each of the valves 25a and 25b may include, for example, a flow rate regulating valve and an on-off valve.

[0085] The supply unit 23a is communicatively connected to a supply source 26a. For example, the supply source 26a is connected to the pipe 24a. The supply source 26a sends the sublimable substance to the supply unit 23a. Similarly, the supply unit 23b is communicatively connected to a supply source 26b. For example, the supply source 26b is connected to the pipe 24b. The supply source 26b sends the solvent to the supply unit 23b.

[0086] The pumping unit 31 includes a pipe 32 and a joint 33. The pipe 32 is communicatively connected to the tank 22. The joint 33 is connected to the pipe 32. The joint 33 is further connected to the pipe 17a. The pipe 32 is communicatively connected to the pipe 17a by the joint 33. Therefore, the tank 22 is communicatively connected to the first supply unit 15a via the pipe 32 and the joint 33. The tank 22 is communicatively connected to the nozzle 16a.

[0087] The pumping unit 31 further includes a pump 34 and a filter 35. The pump 34 is provided in the piping 32. When the pump 34 is operating, the pump 34 pumps the processing liquid g from the tank 22 to the first supply section 15a. When the pump 34 is stopped operating, the pump 34 does not pump the processing liquid g from the tank 22 to the first supply section 15a. The filter 35 is provided in the piping 32. The processing liquid g passes through the filter 35. The filter 35 filters the processing liquid g. The filter 35 removes foreign matter from the processing liquid g.

[0088] See Fig. 3. The control unit 10 is capable of communicating with the first supply source 19a. The control unit 10 controls the first supply source 19a. The control unit 10 controls the generation unit 21. The control unit 10 controls the supply units 23a and 23b. The control unit 10 controls the valves 25a and 25b. The control unit 10 controls the pumping unit 31. The control unit 10 controls the pump 34.

[0089] The control unit 10 has processing liquid condition information for controlling the first supply source 19a. The processing liquid condition information includes, for example, a target value for the volume ratio RV of the processing liquid g. The processing liquid condition information is stored in advance in a storage medium of the control unit 10.

[0090] 6. Operational Example of First Supply Source 19a and Processing Unit 11 5 is a flowchart showing the steps of a substrate processing method according to an embodiment. The substrate processing method includes step S1 and steps S11-S18. Step S1 is performed by first supply source 19a. Steps S11-S18 are substantially performed by processing unit 11. Step S1 is performed in parallel with steps S11-S18. First supply source 19a and processing unit 11 operate under the control of control unit 10.

[0091] Each of steps S1, S11 to S18 will be described with reference to FIG. 4 as needed.

[0092] Step S1: Processing liquid generation process In the processing liquid generating step, processing liquid g is generated.

[0093] The generation unit 21 generates the processing liquid g. Specifically, the supply unit 23a supplies the sublimable substance to the tank 22. The supply unit 23b supplies the solvent to the tank 22. The processing liquid g is generated in the tank 22. The processing liquid g is stored in the tank 22.

[0094] The control unit 10 controls the valves 25a and 25b. Thereby, the control unit 10 adjusts the volume ratio RV of the processing liquid g in the tank 22 to the target value specified in the processing liquid condition information.

[0095] Step S11: Rotation start step The substrate holding unit 13 holds the substrate W. The substrate W is held in a substantially horizontal posture. The rotation driving unit 14 rotates the substrate holding unit 13. Thereby, the substrate W held by the substrate holding unit 13 starts to rotate.

[0096] In steps S12 - S17 described later, the substrate W continues to rotate, for example.

[0097] Step S12: Chemical solution supply step In the chemical solution supply step, the chemical solution is supplied to the substrate W.

[0098] The second supply unit 15b supplies the chemical solution to the substrate W held by the substrate holding unit 13. Specifically, the valve 18b opens. The nozzle 16b discharges the chemical solution. The chemical solution is supplied to the upper surface of the substrate W. For example, the chemical solution etches the substrate W. For example, the chemical solution removes the natural oxide film from the substrate W.

[0099] Thereafter, the second supply unit 15b stops supplying the chemical solution to the substrate W. Specifically, the valve 18b closes. The nozzle 16b stops discharging the chemical solution.

[0100] Step S13: Rinse liquid supply step In the rinse liquid supply step, the rinse liquid is supplied to the substrate W.

[0101] The third supply unit 15c supplies the rinse liquid to the substrate W held by the substrate holding unit 13. Specifically, the valve 18c opens. The nozzle 16c discharges the rinse liquid. The rinse liquid is supplied to the upper surface of the substrate W. For example, the rinse liquid cleans the substrate W. For example, the rinse liquid removes the chemical solution from the substrate W.

[0102] After that, the third supply unit 15c stops supplying the rinse liquid to the substrate W. Specifically, the valve 18c closes. The nozzle 16c stops discharging the rinse liquid.

[0103] Step S14: Replacement Liquid Supply Process In the replacement liquid supply process, the replacement liquid is supplied to the substrate W.

[0104] The fourth supply unit 15d supplies the replacement liquid to the substrate W held by the substrate holding unit 13. Specifically, the valve 18d opens. The nozzle 16d discharges the replacement liquid. The replacement liquid is supplied to the upper surface of the substrate W. The replacement liquid removes the rinse liquid from the substrate W. The rinse liquid on the substrate W is replaced by the replacement liquid.

[0105] After that, the fourth supply unit 15d stops supplying the replacement liquid to the substrate W. Specifically, the valve 18d closes. The nozzle 16d stops discharging the replacement liquid.

[0106] Step S15: Processing Liquid Supply Process In the processing liquid supply process, the processing liquid g is supplied to the substrate W.

[0107] The pressure feeding unit 31 supplies the processing liquid g to the first supply unit 15a. The first supply unit 15a supplies the processing liquid g to the substrate W held by the substrate holding unit 13. Specifically, the pump 34 pressure-feeds the processing liquid g from the tank 22 to the first supply unit 15a. The valve 18a opens. The nozzle 16a discharges the processing liquid g. The processing liquid g is supplied to the upper surface of the substrate W. The processing liquid g removes the replacement liquid from the substrate W. The replacement liquid on the substrate W is replaced by the processing liquid g.

[0108] Thereafter, the pressure-feeding unit 31 stops the supply of the processing liquid g to the first supply unit 15a. The first supply unit 15a stops the supply of the processing liquid g to the substrate W. Specifically, the pump 34 stops. The valve 18a closes. The nozzle 16a stops discharging the processing liquid g.

[0109] FIG. 6 is a diagram schematically showing the substrate W in the processing liquid supply step. When the substrate W is held by the substrate holding unit 13, the pattern P is located on the upper surface of the substrate W. When the substrate W is held by the substrate holding unit 13, the pattern P faces upward.

[0110] The processing liquid g on the substrate W forms a liquid film G. The liquid film G is located on the substrate W. The liquid film G is in contact with the substrate W. The liquid film G covers the substrate W. The liquid film G covers the upper surface of the substrate W.

[0111] All of the pattern P is immersed in the liquid film G. All of the convex portions W1 are immersed in the liquid film G. The concave portion A is filled with the liquid film G. All of the concave portion A is filled only with the liquid film G.

[0112] The liquid film G has an upper surface G1. The upper surface G1 is located at a position higher than all of the pattern P. The upper surface G1 does not intersect with the pattern P. The upper surface G1 is located at a position higher than all of the convex portions W1. The upper surface G1 does not intersect with the convex portions W1.

[0113] Note that the replacement liquid has already been removed from the substrate W by the processing liquid g. Therefore, the replacement liquid does not exist on the substrate W. The replacement liquid does not remain in the concave portion A.

[0114] The gas J exists above the liquid film G. The pattern P does not contact the gas J. The pattern P is not exposed to the gas J. The convex portion W1 does not contact the gas J. The convex portion W1 is not exposed to the gas J.

[0115] The gas J contacts the liquid film G. The gas J contacts the upper surface G1. The upper surface G1 corresponds to the gas-liquid interface between the liquid film G and the gas J. Therefore, the pattern P does not intersect with the gas-liquid interface. The convex portion W1 does not intersect with the gas-liquid interface.

[0116] In the treatment liquid supply step, the height position of the upper surface G1 may be further adjusted. For example, while the nozzle 16a supplies the treatment liquid g to the substrate W, the height position of the upper surface G1 may be adjusted. For example, after the nozzle 16a stops supplying the treatment liquid g, the height position of the upper surface G1 may be adjusted. For example, by adjusting the rotation speed of the substrate W, the height position of the upper surface G1 may be adjusted. For example, by adjusting the rotation time of the substrate W, the height position of the upper surface G1 may be adjusted.

[0117] Here, adjusting the height position of the upper surface G1 corresponds to adjusting the thickness H of the liquid film G. The thickness H of the liquid film G is, for example, the distance in the vertical direction Z between the lower end W1a of the convex portion W1 and the upper surface G1.

[0118] Step S16: Solidified film forming step In the solidified film forming step, the solvent evaporates from the treatment liquid g on the substrate W. In the solidified film forming step, a solidified film is formed on the substrate W. The solidified film contains a sublimable substance.

[0119] FIG. 7 is a diagram schematically showing the substrate W in the solidified film forming step. As described above, the solvent has a relatively high vapor pressure. At room temperature, the solvent has a higher vapor pressure than the sublimable substance. Therefore, the solvent smoothly evaporates from the treatment liquid g on the substrate W. The solvent smoothly changes from a liquid to a gas.

[0120] When the solvent evaporates from the treatment liquid g on the substrate W, the solvent leaves the treatment liquid g on the substrate W. As the solvent evaporates from the treatment liquid g on the substrate W, the amount of the solvent contained in the liquid film G decreases. As the amount of the solvent contained in the liquid film G decreases, the volume ratio RV of the liquid film G increases.

[0121] Eventually, the sublimable substance in the liquid film G begins to precipitate on the substrate W. That is, the sublimable substance changes from the solute of the treatment liquid g to the solid sublimable substance. The solid sublimable substance forms the solidified film K. The solidified film K does not contain a solvent. The solidified film K is solid. The solidified film K is formed on the substrate W.

[0122] Due to the evaporation of the solvent and the precipitation of the sublimable substance, the liquid film G gradually decreases. Due to the precipitation of the sublimable substance, the liquid film G gradually changes into a solidified film K. Due to the precipitation of the sublimable substance, the solidified film K gradually increases.

[0123] First, the upper part of the liquid film G changes into a solidified film K. The solidified film K is located above the liquid film G. The solidified film K covers the upper surface G1 of the liquid film G.

[0124] When the solidified film K covers the entire upper surface G1, the solidified film K separates the liquid film G from the gas J. The liquid film G is in contact with the solidified film K. The gas J is in contact with the solidified film K. The liquid film G is not in contact with the gas J. The upper surface G1 is not in contact with the gas J. The gas-liquid interface between the liquid film G and the gas J disappears.

[0125] Therefore, the pattern P does not intersect with the gas-liquid interface. The liquid film G does not exert a significant force on the pattern P. The convex portion W1 does not intersect with the gas-liquid interface. The liquid film G does not exert a significant force on the convex portion W1.

[0126] As the solidified film K increases, the height position of the upper surface G1 gradually becomes lower. As the solidified film K increases, the thickness H of the liquid film G gradually becomes smaller. Without the liquid film G exerting a significant force on the convex portion W1, the liquid film G decreases. Without the solvent exerting a significant force on the convex portion W1, the solvent leaves the substrate W.

[0127] FIG. 8 is a diagram schematically showing the substrate W in the solidified film forming step. FIG. 8 schematically shows the substrate W, for example, at the end of the solidified film forming step. At the end of the solidified film forming step, all of the liquid film G disappears from above the substrate W. The liquid film G does not remain in the concave portion A. All of the solvent disappears from above the substrate W. The solvent also does not remain in the concave portion A.

[0128] The recessed portion A is filled with the solidified film K. All of the recessed portion A is filled only with the solidified film K. The pattern P is in contact with the solidified film K. The solidified film K supports the pattern P. The solidified film K protects the pattern P. For example, the solidified film K prevents the pattern P from collapsing. The convex portion W1 is in contact with the solidified film K. The solidified film K supports the convex portion W1. The solidified film K protects the convex portion W1. For example, the solidified film K prevents the convex portion W1 from collapsing.

[0129] Step S17: Sublimation process In the sublimation process, the solidified film K sublimates.

[0130] The fifth supply unit 15e supplies a drying gas to the substrate W held by the substrate holding unit 13. Specifically, the valve 18e opens. The nozzle 16e discharges the drying gas. The nozzle 16e blows out the drying gas onto the substrate W. The drying gas is supplied to the upper surface of the substrate W. The drying gas is supplied to the solidified film K. The solidified film K is exposed to the drying gas. Thereby, the solidified film K sublimates. The solidified film K changes into a gas without passing through a liquid state. Due to the sublimation of the solidified film K, the solidified film K is removed from the substrate W.

[0131] After that, the fifth supply unit 15e stops supplying the drying gas to the solidified film K. Specifically, the valve 18e closes. The nozzle 16e stops blowing out the drying gas.

[0132] FIG. 9 is a diagram schematically showing the substrate W in the sublimation process. As the solidified film K sublimates, the solidified film K gradually decreases. As the solidified film K sublimates, the solidified film K gradually becomes thinner.

[0133] The pattern P begins to be exposed to the gas J. The convex portion W1 begins to be exposed to the gas J.

[0134] When the solidified film K sublimates, the solidified film K does not change into a liquid. Therefore, in the sublimation process, no liquid exists on the substrate W. In the sublimation process, no liquid exists in the recessed portion A. In the sublimation process, no gas-liquid interface is generated in the vicinity of the pattern P.

[0135] Therefore, the pattern P does not intersect with the gas-liquid interface. The solidified film K does not exert a significant force on the pattern P. Without the solidified film K exerting a significant force on the pattern P, the solidified film K detaches from the substrate W. The convex portion W1 does not intersect with the gas-liquid interface. The solidified film K does not exert a significant force on the convex portion W1. Without the solidified film K exerting a significant force on the convex portion W1, the solidified film K detaches from the substrate W.

[0136] FIG. 10 is a diagram schematically showing the substrate W in the sublimation process. FIG. 10 schematically shows the substrate W, for example, at the end of the sublimation process. At the end of the sublimation process, all of the solidified film K disappears from above the substrate W. The liquid does not exist on the substrate W. All of the pattern P is exposed to the gas. All of the convex portions W1 are exposed to the gas. All of the concave portions A are filled only with the gas J. The substrate W is dried.

[0137] The processes in the above-described treatment liquid supply step, solidified film formation step, and sublimation step are examples of a drying process. The processes in the above-described treatment liquid supply step, solidified film formation step, and sublimation step correspond to examples of the use of the treatment liquid g. The treatment liquid g is used in an environment at normal temperature. The treatment liquid g is used in an environment at normal pressure.

[0138] Step S18: Rotation stop step The rotation drive unit 14 stops the rotation of the substrate holding unit 13. The substrate W held by the substrate holding unit 13 stops rotating. The substrate W becomes stationary. The processing unit 11 finishes the processing on the substrate W.

[0139] <7. Technical significance of the treatment liquid g> The technical significance of the treatment liquid g is explained by experimental examples and comparative examples.

[0140] The conditions of the experimental example are explained. In the experimental example, the substrate W undergoes a series of processes including a chemical solution supply step, a rinse solution supply step, a replacement solution supply step, a treatment liquid supply step, a solidified film formation step, and a sublimation step.

[0141] The chemical used in the chemical supplying step is hydrofluoric acid. Hydrofluoric acid is a mixture of hydrogen fluoride and water. The volume ratio of hydrogen fluoride to water is as follows: Hydrogen fluoride:water = 1:10 (volume ratio)

[0142] The rinse liquid used in the rinse liquid supply step is deionized water (DIW).

[0143] The substitute liquid used in the substitute liquid supplying step is isopropyl alcohol.

[0144] The processing solution g used in the processing solution supplying step consists of a sublimable substance and a solvent. The sublimable substance is 4-nitrotoluene. The solvent is isopropyl alcohol (IPA). The volume ratio RV of the processing solution g is 2.5 [Vol%].

[0145] In the solidified film forming step, the substrate W is rotated at a rotation speed of 1500 rpm.

[0146] In the sublimation step, a dry gas is supplied to the substrate W while the substrate W is rotated at a rotation speed of 1500 rpm.

[0147] The conditions of the comparative example will be explained. The only difference between the comparative example and the experimental example is the sublimable substance. In the comparative example, the sublimable substance is cyclohexanone oxime. Other conditions of the comparative example are the same as those of the experimental example.

[0148] Each substrate W processed in the experimental example and comparative example was evaluated by an average collapse rate Fa, which is the average value of a plurality of local collapse rates Fi.

[0149] The local failure rate Fi is the failure rate in a plurality of local areas Pi. Here, i is an arbitrary natural number from 1 to N. N is the number of local areas Pi. Each local area Pi is a minute area of the substrate W. Each local area Pi is magnified 50,000 times, for example, by a scanning electron microscope. An observer observes the pattern P (protrusion W1) in each local area Pi. The observer determines each protrusion W1 in each local area Pi one by one. Specifically, the observer determines whether or not the protrusion W1 has failed for each protrusion W1. The observer counts the number Ei of the determined protrusions W1 in each local area Pi. The observer counts the number ei of the failed protrusions W1 in each local area Pi. The number ei is less than or equal to the number Ei. The local failure rate Fi is the ratio of the number ei to the number Ei. The local failure rate Fi is defined, for example, by the following equation. Fi = ei / Ei * 100 (%)

[0150] The average failure rate Fa is a value obtained by dividing the sum of the local failure rates Fi in each local area Pi by the number N of the local areas Pi.

[0151] In the experimental example, the average failure rate Fa was 2.70%. In the comparative example, the average failure rate Fa was 4.45%. The average failure rate Fa in the experimental example was lower than the average failure rate Fa in the comparative example. In the experimental example, the pattern P of the substrate W was less likely to fail than in the comparative example.

[0152] Therefore, in the experimental example, the pattern P formed on the substrate W was more appropriately protected than in the comparative example. That is, in the experimental example, the substrate W was dried more appropriately than in the comparative example.

[0153] <8. Effects of the Embodiment> The substrate processing method of the embodiment is for processing a substrate W on which a pattern P is formed. The substrate processing method includes a processing liquid supplying step, a solidified film forming step, and a sublimation step. In the processing liquid supplying step, a processing liquid g is supplied to the substrate W. The processing liquid g contains a sublimable substance and a solvent. In the solidified film forming step, the solvent evaporates from the processing liquid g on the substrate W. In the solidified film forming step, a solidified film K is formed on the substrate W. The solidified film K contains a sublimable substance. In the sublimation step, the solidified film K sublimes. The substrate is dried by sublimation of the solidified film. Here, the sublimable substance is 4-nitrotoluene. That is, the processing liquid g contains 4-nitrotoluene and a solvent. Therefore, the solidified film K contains 4-nitrotoluene. Therefore, the substrate W is properly dried. Specifically, the substrate W is dried while the pattern P formed on the substrate W is properly protected.

[0154] The solvent is isopropyl alcohol. Isopropyl alcohol dissolves 4-nitrotoluene well. Therefore, it is easy to use a processing solution g containing 4-nitrotoluene as a sublimable substance. For example, in the processing solution supplying step, the processing solution g containing 4-nitrotoluene is appropriately supplied to the substrate W.

[0155] Isopropyl alcohol evaporates more easily than 4-nitrotoluene. Therefore, in the solidified film forming step, isopropyl alcohol evaporates suitably from the processing solution g on the substrate W. Therefore, in the solidified film forming step, the solidified film K is suitably formed on the substrate W. Therefore, the substrate W is dried more suitably.

[0156] The substrate processing method includes a processing liquid generating step in which a processing liquid g is generated, and thus the processing liquid g is suitably prepared.

[0157] As described above, isopropyl alcohol dissolves 4-nitrotoluene well, and therefore, in the treatment liquid production step, treatment liquid g containing 4-nitrotoluene is produced well.

[0158] As described above, isopropyl alcohol preferably dissolves 4-nitrotoluene. Therefore, the treatment liquid g containing 4-nitrotoluene is preferably stored.

[0159] The substrate processing apparatus 1 includes a substrate holding unit 13 and a first supply unit 15a. The substrate holding unit 13 holds the substrate W. The treatment liquid supply unit 15a supplies the treatment liquid g to the substrate W held by the substrate holding unit 13. The treatment liquid g contains a sublimable substance and a solvent. The sublimable substance is 4-nitrotoluene. Therefore, when the treatment liquid g is supplied to the substrate W, the solvent preferably evaporates from the treatment liquid g on the substrate W. Thus, the solidified film K is preferably formed on the substrate W. The solidified film K contains 4-nitrotoluene. Therefore, the solidified film K sublimates appropriately. Due to the sublimation of the solidified film K, the substrate W is appropriately dried. As described above, according to the substrate processing apparatus 1, the substrate W is appropriately dried.

[0160] The solvent is isopropyl alcohol. As described above, isopropyl alcohol preferably dissolves 4-nitrotoluene. Isopropyl alcohol evaporates more easily than 4-nitrotoluene. Therefore, the substrate W is dried more appropriately.

[0161] The treatment liquid g is used for drying the substrate on which the pattern P is formed. Specifically, the treatment liquid g is a drying aid liquid. The treatment liquid g contains a sublimable substance and a solvent. The sublimable substance is 4-nitrotoluene. Therefore, the treatment liquid g is useful for drying the substrate W. Specifically, by using the treatment liquid g, the pattern P formed on the substrate W is preferably protected while the substrate W is dried. As described above, using the treatment liquid g, the substrate W is appropriately dried.

[0162] The solvent is isopropyl alcohol. As described above, isopropyl alcohol preferably dissolves 4-nitrotoluene. Isopropyl alcohol evaporates more easily than 4-nitrotoluene. Therefore, the treatment liquid g is more useful for drying the substrate W. Using the treatment liquid g, the substrate W is dried more appropriately.

[0163] As described above, isopropyl alcohol dissolves 4-nitrotoluene favorably. Therefore, the handling of the processing solution g containing 4-nitrotoluene is easy. For example, it is easy to prepare the processing solution g containing 4-nitrotoluene. For example, it is easy to produce the processing solution g containing 4-nitrotoluene. For example, it is easy to store the processing solution g containing 4-nitrotoluene. For example, it is easy to use the processing solution g containing 4-nitrotoluene.

[0164] <9. Modified Embodiment> The present invention is not limited to the embodiments, and can be modified as follows.

[0165] (1) In the embodiment, the processing liquid g is generated before the processing liquid g is supplied to the first supply unit 15a. In the embodiment, the first supply source 19a generates the processing liquid in the tank 22. However, this is not limited to this. For example, the processing liquid g may be generated when the processing liquid g is supplied to the first supply unit 15a. For example, the first supply source 19a may generate the processing liquid g in a flow path that supplies the processing liquid g to the first supply unit 15a.

[0166] 11 is a diagram showing the configuration of a processing unit 11 and a first supply source 19a according to a modified embodiment. Note that the same components as those in the embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0167] The first supply source 19a includes a first tank 41 and a second tank 42. The first tank 41 stores a sublimable substance. For example, the first tank 41 may store a solvent together with the sublimable substance. The second tank 42 stores a solvent. For example, the second tank 42 stores only the solvent.

[0168] The first supply source 19a includes a mixer 44. The mixer 44 is connected in communication with the first tank 41 and the second tank 42. The mixer 44 produces a treatment liquid g.

[0169] The mixer 44 is connected in communication with the first supply unit 15a and supplies the treatment liquid g to the first supply unit 15a.

[0170] Specifically, the mixing unit 44 includes pipes 45a and 45b and a joint 46. Pipe 45a is communicatively connected to the first tank 41. Pipe 45b is communicatively connected to the second tank 42. Joint 46 is communicatively connected to pipes 45a and 45b. Joint 46 is further communicatively connected to pipe 17a. Pipes 45a and 45b are communicatively connected to pipe 17a via joint 46.

[0171] The mixing unit 44 includes pumps 47a and 47b. Pumps 47a and 47b are respectively provided in pipes 45a and 45b. Pump 47a sends the sublimable substance from the first tank 41 to joint 46 through pipe 45a. Pump 47b sends the solvent from the second tank 42 to joint 46 through pipe 45b.

[0172] The mixing unit 44 includes filters 48a and 48b. Filters 48a and 48b are respectively provided in pipes 45a and 45b. The sublimable substance passes through filter 48a. Filter 48a filters the sublimable substance. The solvent passes through filter 48b. Filter 48b filters the solvent.

[0173] The mixing unit 44 includes valves 49a and 49b. Valves 49a and 49b are respectively provided in pipes 45a and 45b. Valve 49a adjusts the flow rate of the sublimable substance flowing through pipe 45a. Valve 49b adjusts the flow rate of the solvent flowing through pipe 45b. Valves 49a and 49b may each include, for example, a flow control valve. Valves 49a and 49b may each include, for example, a flow control valve and an on-off valve.

[0174] An operation example of the first supply source 19a in the modified embodiment will be described. In the processing liquid supply step, the first supply source 19a generates the processing liquid g and sends the processing liquid g to the first supply unit 15a. Specifically, the valves 49a and 49b open. The pump 47a pumps the sublimable substance from the first tank 41 to the joint 46. The pump 47b pumps the solvent from the second tank 42 to the joint 46. The sublimable substance and the solvent are mixed at the joint 46. The sublimable substance and the solvent become the processing liquid g at the joint 46. Further, the processing liquid g flows from the joint 46 to the first supply unit 15a. The nozzle 16a discharges the processing liquid g.

[0175] According to this modified embodiment, it is not necessary to store the processing liquid g before the processing liquid g is supplied to the first supply unit 15a. Therefore, the volume ratio RV of the processing liquid is accurately controlled. Thus, the substrate W is dried more appropriately.

[0176] Furthermore, the first supply source 19a does not include the tank 22. Therefore, the structure of the first supply source 19a is preferably simplified. The first supply source 19a is preferably miniaturized.

[0177] (2) The substrate processing method of the embodiment includes a chemical liquid supply step, a rinse liquid supply step, and a replacement liquid supply step. However, it is not limited to this. For example, at least any one of the chemical liquid supply step, the rinse liquid supply step, and the replacement liquid supply step may be omitted. For example, all of the chemical liquid supply step, the rinse liquid supply step, and the replacement liquid supply step may be omitted.

[0178] (3) In the embodiment, when the processing liquid supply step is executed, a liquid (for example, a replacement liquid) was present on the substrate W. That is, in the processing liquid supply step, the processing liquid g was supplied to the substrate W in a non-dried state. However, it is not limited to this. For example, when the processing liquid supply step is executed, the liquid (for example, a replacement liquid) may not be present on the substrate W. For example, in the processing liquid supply step, the processing liquid g may be supplied to the dried substrate W.

[0179] (4) In the processing liquid supply step of the embodiment, the processing liquid g removed the replacement liquid from the substrate W. However, it is not limited thereto. For example, in the processing liquid supply step, the processing liquid g may clean the substrate W. For example, in the processing liquid supply step, the processing liquid g may remove foreign matter adhering to the substrate W. For example, in the processing liquid supply step, the processing liquid g may dissolve foreign matter adhering to the substrate W. The foreign matter is, for example, a resist residue.

[0180] (5) In the solidified film formation step of the embodiment, the drying gas was not supplied to the substrate W. However, it is not limited thereto. In the solidified film formation step, the drying gas may be supplied to the substrate W. In the solidified film formation step, the drying gas may be supplied to the processing liquid g on the substrate W. According to this modified embodiment, in the solidified film formation step, the processing liquid g on the substrate W is exposed to the drying gas. Therefore, in the solidified film formation step, the solvent efficiently evaporates from the processing liquid g on the substrate W. In the solidified film formation step, the solidified film K is efficiently formed on the substrate W.

[0181] (6) In the embodiment, the pattern P on the substrate W may be formed on the substrate W, for example, before the processing unit 11 processes the substrate W. Alternatively, the pattern P may be formed on the substrate W, for example, in the chemical liquid supply step (step S12).

[0182] (7) Regarding the embodiment and each of the modified embodiments described in (1) to (6) above, each configuration may be appropriately changed by replacing or combining each configuration with the configuration of other modified embodiments.

Explanation of Reference Numerals

[0183] 1... Substrate processing apparatus 10... Control unit 11... Processing unit 13... Substrate holding unit 15... Supply unit 15a... First supply unit (processing liquid supply unit) 19a... First supply source g... Processing liquid G... Liquid film of the processing liquid G1: Upper surface of the liquid film H: Liquid film thickness K: Solidified film W: Substrate P... Pattern W1: Convex part A ... recess

Claims

1. A substrate processing method for processing a substrate on which a pattern is formed, comprising: a processing liquid supply step of supplying a processing liquid containing a sublimable substance and a solvent to the substrate; a solid film forming step of evaporating the solvent from the processing liquid on the substrate to form a solid film containing the sublimable substance on the substrate; a sublimation step of sublimating the solid film; and wherein the sublimable substance is 4-nitrotoluene substrate processing method.

2. In the substrate processing method according to Claim 1, the solvent is isopropyl alcohol substrate processing method.

3. A substrate processing apparatus, comprising: a substrate holding unit for holding a substrate; a processing liquid supply unit for supplying a processing liquid containing a sublimable substance and a solvent to the substrate held by the substrate holding unit; and wherein the sublimable substance is 4-nitrotoluene substrate processing apparatus.

4. In the substrate processing apparatus according to Claim 3, the solvent is isopropyl alcohol substrate processing apparatus.

5. A processing liquid used for drying a substrate on which a pattern is formed, wherein the processing liquid contains a sublimable substance and a solvent, and wherein the sublimable substance is 4-nitrotoluene, and the solvent is isopropyl alcohol processing liquid.

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