Substrate treatment method, substrate treatment apparatus, and treatment solution

Abstract

The present invention relates to a substrate treatment method, a substrate treatment apparatus, and a treatment solution. The substrate treatment method comprises a treatment solution supply step, a solidified film formation step, and a sublimation step. In the treatment solution supply step, a treatment solution is supplied to a substrate. The treatment solution comprises a sublimable substance and a solvent. In the solidified film formation step, the solvent is evaporated from the treatment solution on the substrate. In the solidified film formation step, a solidified film is formed on the substrate. The solidified film contains the sublimable substance. In the sublimation step, the solidified film is sublimated. The substrate is dried as a result of the sublimation of the solidified film. The sublimable substance comprises at least one component selected from N-methyl-p-toluenesulfonamide, 2-methyl-8-quinolinol and N-tert-butylacrylamide.

Description

Substrate processing method, substrate processing apparatus, and processing liquid

[0001] The present invention relates to a substrate processing method, a substrate processing apparatus, and a processing solution for substrates such as semiconductor wafers, liquid crystal display substrates, organic electroluminescence (EL) substrates, FPD (Flat Panel Display) substrates, optical display substrates, magnetic disk substrates, optical disk substrates, magneto-optical disk substrates, photomask substrates, and solar cell substrates.

[0002] Patent Document 1 discloses a substrate processing method for processing a substrate. Specifically, the substrate processing method of Patent Document 1 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 a substrate. The processing liquid contains a solvent and a sublimable substance. In the solidified film forming step, the solvent is evaporated and a solidified film is formed on the substrate. The solidified film contains a sublimable substance. In the sublimation step, the solidified film sublimes. The solidified film changes into a gas without passing through a liquid state. The substrate is dried by the sublimation of the solidified film. Here, the sublimable substance contains at least one of pinacoline oxime, acetophenone oxime, cyclopentanone oxime, and 4-tert-butylphenol.

[0003] JP 2022-170681 A

[0004] Even with conventional substrate processing methods, there are cases where the substrate cannot be dried properly. For example, even with conventional substrate processing methods, there are cases where patterns formed on the substrate collapse. When the pattern is fine, the strength of the pattern is weak. Therefore, even with conventional substrate processing methods, there are cases where the fine pattern collapses.

[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.

[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 has been 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 contains at least one of N-methyl-p-toluenesulfonamide, 2-methyl-8-quinolinol, and N-tert-butylacrylamide.

[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 contains 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 contains a sublimable substance. In the sublimation step, the solidified film is sublimated. The substrate is dried by the sublimation of the solidified film.

[0008] Here, the sublimable substance includes at least one of N-methyl-p-toluenesulfonamide, 2-methyl-8-quinolinol, and N-tert-butylacrylamide. Therefore, the treatment liquid includes at least one of N-methyl-p-toluenesulfonamide, 2-methyl-8-quinolinol, and N-tert-butylacrylamide. Therefore, in the solidified film formation step, a solidified film is suitably formed on the substrate.

[0009] The solidified film contains at least one of N-methyl-p-toluenesulfonamide, 2-methyl-8-quinolinol, and N-tert-butylacrylamide. Therefore, the solidified film sublimes appropriately in the sublimation process. That is, the substrate is dried appropriately in the sublimation process. Specifically, in the sublimation process, the substrate is dried while the pattern formed on the substrate is suitably protected.

[0010] As described above, according to the present substrate processing method, the substrate is properly dried.

[0011] In the above-described substrate processing method, the solvent is preferably isopropyl alcohol. Isopropyl alcohol preferably dissolves N-methyl-p-toluenesulfonamide, 2-methyl-8-quinolinol, and N-tert-butylacrylamide. Therefore, the substrate can be more appropriately dried.

[0012] 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 contains at least one of N-methyl-p-toluenesulfonamide, 2-methyl-8-quinolinol, and N-tert-butylacrylamide.

[0013] 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 a processing liquid to the substrate held by the substrate holding unit. The processing liquid includes a sublimable substance and a solvent.

[0014] Here, the sublimable substance includes at least one of N-methyl-p-toluenesulfonamide, 2-methyl-8-quinolinol, and N-tert-butylacrylamide. Therefore, the treatment liquid includes at least one of N-methyl-p-toluenesulfonamide, 2-methyl-8-quinolinol, and N-tert-butylacrylamide. Therefore, when the treatment liquid is supplied to a substrate, a solidified film is suitably formed on the substrate.

[0015] The solidified film contains at least one of N-methyl-p-toluenesulfonamide, 2-methyl-8-quinolinol, and N-tert-butylacrylamide. Therefore, the solidified film sublimes appropriately. That is, the substrate is dried appropriately. Specifically, the substrate is dried while the pattern formed on the substrate is suitably protected.

[0016] As described above, according to the present substrate processing apparatus, the substrate is dried appropriately.

[0017] In the substrate processing apparatus described above, the solvent is preferably isopropyl alcohol, which dissolves N-methyl-p-toluenesulfonamide, 2-methyl-8-quinolinol, and N-tert-butylacrylamide well, thereby allowing the substrate to be dried more appropriately.

[0018] 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 includes at least one of N-methyl-p-toluenesulfonamide, 2-methyl-8-quinolinol, and N-tert-butylacrylamide.

[0019] The processing liquid is used to dry the substrate on which the pattern is formed. Specifically, the processing liquid is a drying auxiliary liquid. The processing liquid contains a sublimable substance and a solvent.

[0020] Here, the sublimable substance includes at least one of N-methyl-p-toluenesulfonamide, 2-methyl-8-quinolinol, and N-tert-butylacrylamide. Therefore, the treatment liquid includes at least one of N-methyl-p-toluenesulfonamide, 2-methyl-8-quinolinol, and N-tert-butylacrylamide. Therefore, by supplying the treatment liquid to the substrate, a solidified film is suitably formed on the substrate.

[0021] The solidified film contains at least one of N-methyl-p-toluenesulfonamide, 2-methyl-8-quinolinol, and N-tert-butylacrylamide. Therefore, the solidified film sublimes appropriately. That is, the substrate is dried appropriately. Specifically, the substrate is dried while the pattern formed on the substrate is suitably protected.

[0022] As described above, the substrate is properly dried using the processing liquid. The processing liquid is useful for drying the substrate.

[0023] In the above-described treatment liquid, the solvent is preferably isopropyl alcohol. Isopropyl alcohol preferably dissolves N-methyl-p-toluenesulfonamide, 2-methyl-8-quinolinol, and N-tert-butylacrylamide. Therefore, the substrate can be more appropriately dried using the treatment liquid. The treatment liquid is more useful for drying the substrate.

[0024] In the above-mentioned processing liquid, it is preferable that the processing liquid is supplied to the substrate, the solvent is evaporated from the processing liquid on the substrate, a solidified film containing the sublimable substance is formed on the substrate, and then the solidified film is sublimated. When the processing liquid is used in this manner, the substrate is more appropriately dried. When the processing liquid is used in these procedures, the processing liquid is more useful for drying the substrate.

[0025] According to the substrate processing method, substrate processing apparatus, and processing solution of the present invention, the substrate is dried appropriately.

[0026] FIG. 1 is a diagram schematically showing a portion of a substrate. FIG. 2 is a plan view showing the inside of a substrate processing apparatus of an embodiment. FIG. 3 is a control block diagram of a substrate processing apparatus. FIG. 4 is a diagram showing the configuration of a processing unit and a first supply source. FIG. 5 is a flowchart showing the procedure of a substrate processing method of an embodiment. FIG. 6 is a diagram schematically showing a substrate in a processing liquid supply process. FIG. 7 is a diagram schematically showing a substrate in a solidification film formation process. FIG. 8 is a diagram schematically showing a substrate in a sublimation process. FIG. 9 is a diagram showing the configuration of a processing unit and a first supply source of a modified embodiment, which is a table showing the quality of processing performed on a substrate in Examples 1-3.

[0027] Hereinafter, a substrate processing method, a substrate processing apparatus, and a processing liquid according to the present invention will be described with reference to the drawings.

[0028] <1. Substrate> The substrate W 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 a thin, flat plate shape. The substrate W has a substantially circular shape in a plan view.

[0029] 1 is a diagram schematically illustrating a part of a substrate W. The substrate W has a pattern P. The pattern P is formed on the surface of the substrate W.

[0030] The pattern P has, for example, an uneven 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 made 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. 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, for example, open upward. The convex portion W1 corresponds to a wall that defines the concave portion A.

[0031] 2. Processing Liquid (Drying Auxiliary Liquid) In this specification, the processing liquid used for drying the substrate W is simply referred to as the "processing liquid." The processing liquid has a function of assisting in drying the substrate W. The processing liquid can also be called a drying auxiliary liquid.

[0032] The treatment liquid contains a sublimable substance. A sublimable substance has sublimation properties. "Sublimation" 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.

[0033] The sublimable substance is, for example, compounds a, b, and c. Compound a: N-Methyl-p-toluenesulfonamide Compound b: 2-Methyl-8-quinolinol Compound c: N-tert-Butylacrylamide

[0034] Compound a, ie, N-methyl-p-toluenesulfonamide, is represented by the following chemical formula (1).

[0035]

[0036] Compound b, ie, 2-methyl-8-quinolinol, is represented by the following chemical formula (2).

[0037]

[0038] Compound c, that is, N-tert-butylacrylamide, is represented by the following chemical formula (3).

[0039]

[0040] The sublimable substance includes at least one of compounds a, b, and c. For example, the sublimable substance includes compound a. For example, the sublimable substance includes compounds a and b. For example, the sublimable substance includes compounds a to c.

[0041] For example, the sublimable substance includes at least one of compounds b and c. For example, the sublimable substance includes compound b. For example, the sublimable substance includes compound c. For example, the sublimable substance includes compound b and compound c.

[0042] For example, the sublimable substance consists of only at least one of compounds a to c. For example, the sublimable substance consists of only compound a. For example, the sublimable substance consists of only compounds a and b. For example, the sublimable substance consists of only compounds a to c.

[0043] For example, the sublimable substance consists of only at least one of compounds b and c. For example, the sublimable substance consists of only compound b. For example, the sublimable substance consists of only compound c. For example, the sublimable substance consists of only compounds b and c.

[0044] For example, the sublimable substance is at least one of compounds a to c. For example, the sublimable substance is compound a. For example, the sublimable substance is compound a and compound b. For example, the sublimable substance is compounds a to c.

[0045] For example, the sublimable substance is at least one of compounds b and c. For example, the sublimable substance is compound b. For example, the sublimable substance is compound c. For example, the sublimable substance is compounds b and c.

[0046] The treatment liquid includes a solvent. The solvent is, for example, a liquid. The solvent dissolves the sublimable substance. The sublimable substance in the treatment liquid is dissolved in the solvent. That is, the treatment liquid includes the solvent and the sublimable substance dissolved in the solvent. The sublimable substance corresponds to the solute of the treatment liquid.

[0047] The solvent can change, for example, from a liquid to a gas. The solvent can evaporate from a liquid.

[0048] 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.

[0049] Here, normal temperature includes room temperature. Normal temperature is, for example, a temperature in the range of 5° C. or higher and 35° C. or lower. Normal temperature is, for example, a temperature in the range of 10° C. or higher and 30° C. or lower. Normal temperature is, for example, a temperature in the range of 20° C. or higher and 25° C. or lower.

[0050] The solvent is, for example, an organic solvent. The solvent is, for example, an alcohol.

[0051] The solvent includes, for example, isopropyl alcohol (IPA). The solvent consists, for example, of isopropyl alcohol. The solvent is, for example, isopropyl alcohol.

[0052] For example, the solvent is not water. The treatment liquid includes a sublimable substance and a solvent (but excluding water).

[0053] The processing liquid is, for example, made up of only a sublimable substance and a solvent.The processing liquid is, for example, made up of only a sublimable substance and a solvent (excluding water).

[0054] The treatment liquid is, for example, composed only of at least one of compounds a to c and isopropyl alcohol. The treatment liquid is, for example, composed only of compound a and isopropyl alcohol. The treatment liquid is, for example, composed only of compounds a to c and isopropyl alcohol.

[0055] The treatment liquid is, for example, composed of at least one of compounds b and c and isopropyl alcohol. The treatment liquid is, for example, composed of compound b and isopropyl alcohol. The treatment liquid is, for example, composed of compound c and isopropyl alcohol. The treatment liquid is, for example, composed of compounds b and c and isopropyl alcohol.

[0056] The volume of the sublimable substance contained in the treatment liquid is smaller than the volume of the solvent contained in the treatment liquid.

[0057] The concentration CON of a sublimable substance in a treatment liquid is the ratio of the volume of the sublimation agent to the volume of the treatment liquid. The volume of the treatment liquid is the sum of the volume of the solute and the volume of the solvent. Therefore, the concentration CON may be called the "volume concentration of the sublimable substance in the treatment liquid."

[0058] For example, if the entire solute is a sublimable substance, the volume of the solute is equal to the volume of the sublimable substance. Therefore, the concentration CON of the sublimable substance in the treatment liquid is calculated using the following formula: CON = V1 / (V1 + V2) * 100 [Vol %], where V1 is the volume of the sublimable substance, and V2 is the volume of the solvent.

[0059] For example, the concentration CON of the sublimable substance in the treatment liquid is preferably 1 [Vol %] or more and 20 [Vol %] or less.

[0060] When the sublimable substance is Compound a (i.e., N-methyl-p-toluenesulfonamide), the concentration CON is more preferably 1.96 [Vol%] or more. When the sublimable substance is Compound a, the concentration CON is more preferably 12.50 [Vol%] or less.

[0061] When the sublimable substance is Compound b (i.e., 2-methyl-8-quinolinol), the concentration CON is more preferably 5.88 [Vol %] or more. When the sublimable substance is Compound b, the concentration CON is more preferably 9.09 [Vol %] or less.

[0062] When the sublimable substance is compound c (i.e., N-tert-butylacrylamide), the concentration CON is more preferably 1.96 [Vol %] or more. When the sublimable substance is compound c, the concentration CON is more preferably 2.44 [Vol %] or less.

[0063] 2 is a plan view showing the inside of the substrate processing apparatus 1 according to the embodiment. The substrate processing apparatus 1 processes substrates W. The processing in the substrate processing apparatus 1 includes a drying process.

[0064] 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.

[0065] 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.

[0066] The indexer unit 3 includes a plurality of (for example, four) carrier platforms 4. Each carrier platform 4 mounts one carrier C. Each carrier C accommodates a plurality of substrates W. The carrier C is, for example, a front-opening unified pod (FOUP), a standard mechanical interface (SMIF), or an open cassette (OC).

[0067] The indexer unit 3 includes a transport mechanism 5. The transport mechanism 5 is disposed behind the carrier platform 4. The transport mechanism 5 transports substrates W. The transport mechanism 5 is accessible to the carriers C placed on the carrier platform 4. The transport mechanism 5 is able to approach the carriers C placed on the carrier platform 4. The transport mechanism 5 includes a hand 5a and a hand driver 5b. The hand 5a supports the substrate W. The hand driver 5b is connected to the hand 5a. The hand driver 5b moves the hand 5a. The hand driver 5b moves the hand 5a, for example, in the front-rear direction X, the width direction Y, and the vertical direction Z. The hand driver 5b rotates the hand 5a, for example, in a horizontal plane.

[0068] The processing block 7 includes a transport mechanism 8. The transport mechanism 8 transports substrates W. The transport mechanism 8 and the transport mechanism 5 can exchange substrates W with each other. The transport mechanism 8 includes 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.

[0069] The processing block 7 includes a plurality of processing units (chambers) 11. The processing units 11 are arranged on the sides of the transport mechanism 8. Each processing unit 11 performs processing on a substrate W.

[0070] The processing unit 11 includes a substrate holder 13. The substrate holder 13 is configured to hold a substrate W. The substrate holder 13 includes, for example, at least one of a vacuum chuck, a Bernoulli chuck, and a mechanical chuck. The vacuum chuck and the Bernoulli chuck each suction-hold the substrate W. The vacuum chuck suction-holds, for example, the center of the substrate W. The Bernoulli chuck also suction-holds, for example, the center of the substrate W. The mechanical chuck grips the substrate W. The mechanical chuck grips an edge of the substrate W. The mechanical chuck includes, for example, a plurality of chuck pins. Each chuck pin comes into contact with the edge of the substrate W to hold the substrate W.

[0071] The transport mechanism 8 is accessible to each processing unit 11. The transport mechanism 8 is approachable to each processing unit 11. The transport mechanism 8 can deliver a substrate W to the substrate holder 13. The transport mechanism 8 can take a substrate W from the substrate holder 13.

[0072] 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 is capable of communicating with the transport mechanisms 5 and 8 and the processing units 11. The control unit 10 controls the transport mechanisms 5 and 8 and the processing units 11.

[0073] The control unit 10 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, etc. The control unit 10 has various types of information pre-stored in the storage medium. The information held by the control unit 10 is, for example, transport condition information for controlling the transport mechanisms 5 and 8. The information held 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.

[0074] Referring to Fig. 2, an example of the operation of the substrate processing apparatus 1 will be briefly described.

[0075] The transport mechanisms 5 and 8 transport the substrate W from the carrier C to the processing unit 11. Specifically, the transport mechanism 5 unloads the substrate W from the carrier C. Then, the transport mechanism 5 transports the substrate W from the carrier C to the transport mechanism 8. The transport mechanism 8 transports the substrate W from the transport mechanism 5 to the processing unit 11. The transport mechanism 8 hands over the substrate W to the substrate holder 13 of the processing unit 11.

[0076] The processing unit 11 processes the substrate W. The processing unit 11 processes the substrate W held by the substrate holder 13. The processing unit 11 performs drying processing on the substrate W, for example.

[0077] After the processing units 11 have processed the substrates W, the transport mechanisms 5 and 8 transport the substrates W from each processing unit 11 to the carrier C. Specifically, the transport mechanism 8 takes the substrates W from the substrate holders 13 of the processing units 11. The transport mechanism 8 transports the substrates W from the processing units 11 to the transport mechanism 5. The transport mechanism 5 transports the substrates W from the transport mechanism 8 to the carrier C. The transport mechanism 5 loads the substrates W into the carrier C.

[0078] 4. Configuration of Processing Unit 11> Fig. 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.

[0079] 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.

[0080] The inside of the housing 12 is kept at room temperature, and the temperature of the gas inside the housing 12 is also kept at room temperature, so the substrate W is processed in a room temperature environment.

[0081] The interior of the housing 12 is maintained at atmospheric pressure, and the gas pressure inside the housing 12 is maintained at atmospheric pressure, so that the substrate W is processed in an atmospheric pressure environment.

[0082] 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 values ​​are indicated as absolute pressures based on absolute vacuum.

[0083] The above-described substrate holder 13 is installed inside the housing 12. The substrate holder 13 holds one substrate W. The substrate holder 13 holds the substrate W in a substantially horizontal position.

[0084] The substrate holder 13 is located below the substrate W held by the substrate holder 13. The substrate holder 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 lower surface of the substrate W is also called the backside of the substrate W. The substrate holder 13 does not come into contact with the upper surface of the substrate W.

[0085] The processing unit 11 includes 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.

[0086] 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.

[0087] 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 the above-mentioned 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 substitute liquid. The fifth supply unit 15e supplies a drying gas.

[0088] The first supply unit 15a is an example of the processing liquid supply unit defined in the present invention.

[0089] 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 room pressure.

[0090] The chemical liquid supplied by the second supply unit 15b is, for example, an etching liquid, which includes at least one of hydrofluoric acid (HF) and buffered hydrofluoric acid (BHF).

[0091] The rinse liquid supplied by the third supply unit 15c is, for example, deionized water (DIW).

[0092] The substitute liquid supplied by the fourth supply unit 15d is, for example, an organic solvent or isopropyl alcohol.

[0093] 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.

[0094] The first supply unit 15a includes a nozzle 16a. Similarly, the second to fifth supply units 15b to 15e include nozzles 16b to 16e, respectively. The nozzles 16a to 16e are installed inside the housing 12. The nozzle 16a ejects a processing liquid. The nozzle 16b ejects a chemical liquid. The nozzle 16c ejects a rinse liquid. The nozzle 16d ejects a substitute liquid. The nozzle 16e ejects a drying gas.

[0095] 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 ejects the processing liquid. When the valve 18a is closed, the nozzle 16a does not eject the processing liquid. Similarly, the second to fifth supply units 15b to 15e include pipes 17b to 17e and valves 18b to 18e, respectively. The pipes 17b to 17e are connected to the nozzles 16b to 16e, respectively. The valves 18b to 18e are provided on the pipes 17b to 17e, respectively. The valves 18b to 18e control the ejection of the chemical liquid, the rinse liquid, the replacement liquid, and the drying gas, respectively.

[0096] At least a portion of the pipe 17a may be provided outside the housing 12. The pipes 17b-17e may be arranged in the same manner as the pipe 17a. The valve 18a may be provided outside the housing 12. The valves 18b-18e may be arranged in the same manner as the valve 18a.

[0097] The substrate processing apparatus 1 includes a first supply source 19a. The first supply source 19a is connected to the first supply unit 15a. The first supply source 19a is connected to, for example, a pipe 17a. The first supply source 19a communicates with the first supply unit 15a. The first supply source 19a supplies the processing liquid to the first supply unit 15a.

[0098] The second supply unit 15b is connected to the second supply source 19b. For example, the pipe 17b is connected to the second supply source 19b. The second supply unit 15b is connected to the second supply source 19b. 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. For example, the pipes 17c-17e are connected to the third to fifth supply sources 19c-19e, respectively. The third to fifth supply units 15c-15e are connected to the third to fifth supply sources 19c-19e, 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.

[0099] 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.

[0100] The first supply source 19a may supply the processing liquid to a plurality of 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.

[0101] 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 to 19e may each be a component of the substrate processing apparatus 1. Alternatively, the third to fifth supply sources 19c to 19e may each be a component of the substrate processing apparatus 1.

[0102] The processing unit 11 may further include a cup (not shown). The cup is installed inside the housing 12. The cup is arranged around the substrate holder 13. The cup catches liquid splashed from the substrate W held by the substrate holder 13.

[0103] 3, the control unit 10 controls the rotary drive unit 14. The control unit 10 controls the supply unit 15. The control unit 10 controls the valves 18a-18e.

[0104] 5. Configuration of First Supply Source 19a> Referring to Fig. 4, the first supply source 19a further generates a processing liquid.

[0105] An example of the configuration of the first supply source 19a is shown below. The first supply source 19a is divided into a generation unit 21 and a pumping unit 31. The generation unit 21 generates a treatment liquid. The pumping unit 31 sends the treatment liquid to the first supply part 15a.

[0106] The production unit 21 includes a tank 22 and supply units 23a and 23b. The supply unit 23a supplies a sublimable substance to the tank 22. The supply unit 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 a treatment liquid g in the tank 22.

[0107] The tank 22 is placed in an environment at room temperature. The tank 22 is placed in an environment at normal pressure. Therefore, the processing solution g is produced in an environment at room temperature. The processing solution g is produced in an environment at normal pressure.

[0108] Furthermore, the production unit 21 stores the treatment liquid g. Specifically, the treatment liquid g is stored in a tank 22. Therefore, the treatment liquid g is stored in an environment at room temperature. The treatment liquid g is stored in an environment at normal pressure.

[0109] The supply unit 23a includes, for example, a pipe 24a and a valve 25a. The pipe 24a is connected to the tank 22. The pipe 24a communicates with the tank 22. The valve 25a is provided on the pipe 24a. When the valve 25a is open, the supply unit 23a supplies the sublimable substance to the tank 22. When the valve 25a is closed, 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 connected to the tank 22. The pipe 24b communicates with the tank 22. The valve 25b is provided on the pipe 24b. The valve 25b controls the supply of the solvent to the tank 22.

[0110] 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 concentration CON of the sublimable substance in the treatment liquid g in the tank 22 is controlled by the valves 25a and 25b.

[0111] Each of the valves 25a and 25b may include, for example, a flow rate control valve. Each of the valves 25a and 25b may include, for example, a flow rate control valve and an on-off valve.

[0112] The supply unit 23a is connected to a supply source 26a. For example, the pipe 24a is connected to the supply source 26a. The supply unit 23a is in communication with the supply source 26a. The supply source 26a sends a sublimable substance to the supply unit 23a. Similarly, the supply unit 23b is connected to a supply source 26b. For example, the pipe 24b is connected to the supply source 26b. The supply unit 23b is in communication with the supply source 26b. The supply source 26b sends a solvent to the supply unit 23b.

[0113] The pumping unit 31 includes a pipe 32 and a joint 33. The pipe 32 is connected to the tank 22. The pipe 32 communicates with 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 connected to the pipe 17a via the joint 33. The pipe 32 communicates with the pipe 17a via the joint 33. Therefore, the tank 22 is connected to the first supply unit 15a via the pipe 32 and the joint 33. The tank 22 communicates with the first supply unit 15a via the pipe 32 and the joint 33. Therefore, the tank 22 is connected to the nozzle 16a. The tank 22 communicates with the nozzle 16a.

[0114] 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 sends the processing liquid g from the tank 22 to the first supply unit 15a. When the pump 34 is stopped operating, the pump 34 does not send the processing liquid g from the tank 22 to the first supply unit 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.

[0115] Referring to 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.

[0116] The control unit 10 has processing solution condition information for controlling the first supply source 19 a. The processing solution condition information includes, for example, a target value for the concentration CON of the sublimable substance in the processing solution g. The processing solution condition information is stored in advance in a storage medium of the control unit 10.

[0117] 5 is a flowchart showing the procedure 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 the first supply source 19a. Steps S11-S18 are substantially performed by the processing unit 11. Step S1 is performed in parallel with steps S11-S18. The first supply source 19a and the processing unit 11 operate under the control of the control unit 10.

[0118] Each of steps S1, S11 to S18 will be described with reference to FIG. 4 as needed.

[0119] Step S1: Treatment Liquid Producing Step In the treatment liquid producing step, the treatment liquid g is produced.

[0120] The production unit 21 produces a treatment liquid g. Specifically, the supply unit 23 a supplies a sublimable substance to the tank 22. The supply unit 23 b supplies a solvent to the tank 22. The sublimable substance and the solvent are mixed in the tank 22. That is, the treatment liquid g is produced in the tank 22. The treatment liquid g is stored in the tank 22.

[0121] The control unit 10 controls the valves 25a and 25b, thereby adjusting the concentration CON of the sublimable substance in the processing solution g in the tank 22 to a target value defined in the processing solution condition information.

[0122] Step S11: Rotation Start Step The substrate holding unit 13 holds the substrate W. The substrate W is held in a substantially horizontal position. The rotation drive unit 14 rotates the substrate holding unit 13. As a result, the substrate W held by the substrate holding unit 13 starts to rotate.

[0123] In steps S12-S17 described below, the substrate W continues to rotate, for example.

[0124] Step S12: Chemical Liquid Supplying Step In the chemical liquid supplying step, a chemical liquid is supplied to the substrate W.

[0125] The second supply unit 15b supplies the chemical solution to the substrate W held by the substrate holder 13. Specifically, the valve 18b opens. The nozzle 16b ejects 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 a native oxide film from the substrate W.

[0126] Thereafter, the second supply unit 15b stops supplying the chemical liquid to the substrate W. Specifically, the valve 18b closes, and the nozzle 16b stops discharging the chemical liquid.

[0127] Step S13: Rinse Liquid Supplying Step In the rinse liquid supplying step, a rinse liquid is supplied to the substrate W.

[0128] The third supply unit 15c supplies the rinse liquid to the substrate W held by the substrate holder 13. Specifically, the valve 18c is opened. The nozzle 16c ejects 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 chemicals from the substrate W.

[0129] Thereafter, the third supply unit 15c stops supplying the rinsing liquid to the substrate W. Specifically, the valve 18c closes, and the nozzle 16c stops discharging the rinsing liquid.

[0130] Step S14: Substitute Liquid Supplying Step In the substitute liquid supplying step, the substitute liquid is supplied to the substrate W.

[0131] The fourth supply unit 15d supplies the substitute liquid to the substrate W held by the substrate holder 13. Specifically, the valve 18d opens. The nozzle 16d ejects the substitute liquid. The substitute liquid is supplied to the upper surface of the substrate W. The substitute liquid removes the rinse liquid from the substrate W. The rinse liquid on the substrate W is replaced with the substitute liquid.

[0132] Thereafter, the fourth supply unit 15d stops supplying the substitute liquid to the substrate W. Specifically, the valve 18d closes, and the nozzle 16d stops discharging the substitute liquid.

[0133] Step S15: Processing Liquid Supplying Step In the processing liquid supplying step, the processing liquid g is supplied to the substrate W.

[0134] 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 holder 13. Specifically, the pump 34 sends the processing liquid g from the tank 22 to the first supply unit 15a. The valve 18a opens. The nozzle 16a ejects the processing liquid g. The processing liquid g is supplied to the upper surface of the substrate W. The processing liquid g removes the substitute liquid from the substrate W. The substitute liquid on the substrate W is replaced with the processing liquid g.

[0135] Thereafter, the pressure-feeding unit 31 stops supplying the processing liquid g to the first supply unit 15a. The first supply unit 15a stops supplying the processing liquid g to the substrate W. Specifically, the pump 34 stops. The valve 18a closes. The nozzle 16a stops ejecting the processing liquid g.

[0136] 6 is a diagram schematically showing a substrate W in a processing liquid supply step. When the substrate W is held by the substrate holding part 13, the pattern P is located on the upper surface of the substrate W. When the substrate W is held by the substrate holding part 13, the pattern P faces upward. When the substrate W is held by the substrate holding part 13, the convex part W1 extends upward.

[0137] 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.

[0138] The entire pattern P is immersed in the liquid film G. The entire protrusion W1 is immersed in the liquid film G. The recess A is filled with the liquid film G. The entire recess A is filled with only the liquid film G.

[0139] The liquid film G has an upper surface G1. The upper surface G1 is located at a higher position than the pattern P. The entire upper surface G1 is located at a higher position than the entire pattern P. The upper surface G1 does not intersect with the pattern P. Specifically, the upper surface G1 is located at a higher position than the convex portion W1. The entire upper surface G1 is located at a higher position than the entire convex portion W1. The upper surface G1 does not intersect with the convex portion W1.

[0140] The substitute liquid has already been removed from the substrate W by the processing liquid g. Therefore, the substitute liquid does not exist on the substrate W. The substitute liquid does not remain in the recess A.

[0141] The gas J exists above the liquid film G. The pattern P does not come into contact with the gas J. The pattern P is not exposed to the gas J. The protrusion W1 does not come into contact with the gas J. The protrusion W1 is not exposed to the gas J.

[0142] 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.

[0143] Therefore, in the processing liquid supplying process, the pattern P does not intersect with the gas-liquid interface between the liquid film G and the gas J. In the processing liquid supplying process, the convex portion W1 does not intersect with the gas-liquid interface between the liquid film G and the gas J. Therefore, in the processing liquid supplying process, the pattern P is not subjected to the surface tension of the processing liquid g. In the processing liquid supplying process, the convex portion W1 is not subjected to the surface tension of the processing liquid g.

[0144] In the processing liquid supply step, the height position of the upper surface G1 may further be adjusted. For example, the height position of the upper surface G1 may be adjusted while the nozzle 16a is supplying the processing liquid g to the substrate W. For example, the height position of the upper surface G1 may be adjusted after the nozzle 16a has stopped supplying the processing liquid g. For example, the height position of the upper surface G1 may be adjusted by adjusting the rotation speed of the substrate W. For example, the height position of the upper surface G1 may be adjusted by adjusting the rotation time of the substrate W.

[0145] 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.

[0146] Step S16: Solidified Film Forming Step In the solidified film forming step, the solvent evaporates from the processing liquid g on the substrate W. In the solidified film forming step, the solvent evaporates from the liquid film G. In the solidified film forming step, a solidified film is formed on the substrate W. The solidified film includes a sublimable substance.

[0147] 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 vapor pressure of the solvent is higher than the vapor pressure of the sublimable substance. Therefore, the solvent smoothly evaporates from the processing liquid g on the substrate W. The solvent smoothly evaporates from the liquid film G. The solvent smoothly changes from liquid to gas.

[0148] When the solvent evaporates from the processing liquid g on the substrate W, the solvent leaves the processing liquid g on the substrate W. When the solvent evaporates from the liquid film G, the solvent leaves the liquid film G. As the solvent evaporates from the liquid film G, the amount of solvent contained in the liquid film G decreases. As the amount of solvent contained in the liquid film G decreases, the concentration CON of the sublimable substance in the liquid film G increases.

[0149] Eventually, the sublimable substance in the liquid film G begins to precipitate on the substrate W. That is, the sublimable substance changes from a solute in the processing liquid g to a solid-phase sublimable substance. The solid-phase sublimable substance forms a 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.

[0150] Due to the deposition of the sublimable substance, the liquid film G gradually changes into a solidified film K. Due to the deposition of the sublimable substance, the solidified film K gradually increases in size. Due to the evaporation of the solvent and the deposition of the sublimable substance, the liquid film G gradually decreases in size.

[0151] For example, first, the upper part of the liquid film G is transformed 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.

[0152] 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 gas-liquid interface between the liquid film G and the gas J disappears. Specifically, after the solidified film K covers the entire upper surface G1, the liquid film G does not come into contact with the gas J. The upper surface G1 does not come into contact with the gas J. The upper surface G1 does not correspond to a gas-liquid interface. The liquid film G comes into contact with the solidified film K. The upper surface G1 comes into contact with the solidified film K. The solidified film K comes into contact with the gas J.

[0153] Therefore, in the solidified film forming process, the pattern P does not intersect with the gas-liquid interface. In the solidified film forming process, the convex portions W1 do not intersect with the gas-liquid interface. Therefore, in the solidified film forming process, the pattern P is not subjected to the surface tension of the treatment liquid g. In the solidified film forming process, the convex portions W1 are not subjected to the surface tension of the treatment liquid g.

[0154] As the solidified film K increases, the height position of the upper surface G1 gradually decreases. As the solidified film K increases, the thickness H of the liquid film G gradually decreases.

[0155] Eventually, the upper surface G1 is lowered to the same height as the pattern P. The upper surface G1 is lowered to the same height as the protrusion W1. Therefore, the upper surface G1 intersects with the pattern P. The upper surface G1 intersects with the protrusion W1.

[0156] As described above, the upper surface G1 no longer corresponds to a gas-liquid interface. Therefore, even when the upper surface G1 intersects with the pattern P, the pattern P is not subjected to the surface tension of the processing liquid g. Even when the upper surface G1 intersects with the convex portions W1, the convex portions W1 are not subjected to the surface tension of the processing liquid g. Therefore, the liquid film G does not act on the convex portions W1 with a significant force, and the liquid film G decreases. The solvent leaves the substrate W without acting on the convex portions W1 with a significant force.

[0157] 8 is a diagram schematically showing the substrate W in the solidified film formation process. FIG. 8 schematically shows the substrate W, for example, at the end of the solidified film formation process. At the end of the solidified film formation process, all of the liquid film G has disappeared from the substrate W. The liquid film G is not present on the substrate W. The liquid film G does not remain in the recess A. All of the processing liquid g has disappeared from the substrate W. The processing liquid g is not present on the substrate W. The processing liquid g does not remain in the recess A. All of the solvent has disappeared from the substrate W. The solvent is not present on the substrate W. The solvent also does not remain in the recess A.

[0158] At the end of the solidified film formation process, only the solidified film K exists on the substrate W. The recess A is filled with the solidified film K. The entire recess A is filled with only 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 protrusion W1 is in contact with the solidified film K. The solidified film K supports the protrusion W1. The solidified film K protects the protrusion W1. For example, the solidified film K prevents the protrusion W1 from collapsing.

[0159] Step S17: Sublimation Step In the sublimation step, the solidified film K is sublimated.

[0160] The fifth supply unit 15e supplies dry gas to the substrate W held by the substrate holder 13. Specifically, the valve 18e opens. The nozzle 16e ejects dry gas. The nozzle 16e blows the dry gas onto the substrate W. The dry gas is supplied to the upper surface of the substrate W. The dry gas is supplied to the solidified film K. The solidified film K is exposed to the dry gas. This causes the solidified film K to sublimate. The solidified film K changes into gas without passing through a liquid state. The solidified film K is removed from the substrate W by sublimation.

[0161] Thereafter, the fifth supply unit 15e stops supplying the dry gas to the solidified film K. Specifically, the valve 18e closes, and the nozzle 16e stops blowing the dry gas.

[0162] 9 is a diagram schematically showing the substrate W in the sublimation step. As the solidified film K sublimes, the solidified film K gradually decreases. As the solidified film K sublimes, the solidified film K gradually becomes thinner. The pattern P begins to be exposed to the gas J. The protruding portion W1 begins to be exposed to the gas J.

[0163] When the solidified film K sublimes, the solidified film K does not apply a significant force to the pattern P. The solidified film K leaves the substrate W without applying a significant force to the pattern P. When the solidified film K sublimes, the solidified film K does not apply a significant force to the protrusion W1. The solidified film K leaves the substrate W without applying a significant force to the protrusion W1.

[0164] When the solidified film K sublimates, the solidified film K does not change into the processing liquid g. Therefore, in the sublimation process, the processing liquid g is not generated on the substrate W. Therefore, in the sublimation process, the processing liquid g does not exist on the substrate W. In the sublimation process, the processing liquid g does not exist in the recess A. Therefore, in the sublimation process, a gas-liquid interface between the processing liquid g and the gas J does not occur near the pattern P. In the sublimation process, a gas-liquid interface between the processing liquid g and the gas J does not occur near the protrusion W1.

[0165] When the solidified film K sublimates, the solidified film K does not change into a liquid. Therefore, in the sublimation process, no liquid is generated on the substrate W. Therefore, in the sublimation process, no liquid is present on the substrate W. In the sublimation process, no liquid is present in the recess A. Therefore, in the sublimation process, no gas-liquid interface between the liquid and the gas J is generated near the pattern P. In the sublimation process, no gas-liquid interface between the liquid and the gas J is generated near the protrusion W1.

[0166] Therefore, in the sublimation process, the pattern P does not intersect with the gas-liquid interface. In the sublimation process, the convex portion W1 does not intersect with the gas-liquid interface. Therefore, in the sublimation process, the pattern P is not subjected to the surface tension of the treatment liquid g. In the sublimation process, the pattern P is not subjected to the surface tension of the liquid. In the sublimation process, the convex portion W1 is not subjected to the surface tension of the treatment liquid g. In the sublimation process, the convex portion W1 is not subjected to the surface tension of the liquid.

[0167] Fig. 10 is a diagram schematically showing a substrate W during the sublimation process. Fig. 10 schematically shows, for example, the substrate W at the end of the sublimation process. At the end of the sublimation process, the entire solidified film K disappears from the substrate W. The solidified film K is no longer present on the substrate W. The processing liquid g is no longer present on the substrate W. No liquid is present on the substrate W. The entire pattern P is exposed to the gas J. The entire protrusion W1 is exposed to the gas J. The entire recess A is filled only with the gas J. The substrate W is dried.

[0168] The processes in the above-described processing liquid supplying step, solidified film forming step, and sublimation step are examples of drying processes. The processes in the above-described processing liquid supplying step, solidified film forming step, and sublimation step correspond to examples of using the processing liquid g. Examples of using the processing liquid g are summarized below. The processing liquid g is supplied to the substrate W, the solvent evaporates from the processing liquid g on the substrate W, a solidified film K containing a sublimable substance is formed on the substrate W, and the solidified film K then sublimes.

[0169] The processing solution g is used in an environment at room temperature and under atmospheric pressure.

[0170] Step S18: Rotation Stopping Step The rotation driver 14 stops the rotation of the substrate holder 13. The substrate W held by the substrate holder 13 stops rotating. The substrate W comes to a standstill. The processing unit 11 finishes processing the substrate W.

[0171] 7. Technical Significance of Processing Solution g The technical significance of processing solution g will be explained using Examples 1-3.

[0172] The conditions of Example 1 will be described below: In Example 1, the substrate W undergoes a series of processes including a chemical liquid supplying step, a rinse liquid supplying step, a substitute liquid supplying step, a processing liquid supplying step, a solidified film forming step, and a sublimation step.

[0173] 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).

[0174] The rinse liquid used in the rinse liquid supplying step is deionized water.

[0175] The substitute liquid used in the substitute liquid supplying step is isopropyl alcohol.

[0176] The processing solution g used in the processing solution supplying step is composed of a sublimable substance and a solvent. The sublimable substance is compound a. Specifically, the sublimable substance is N-methyl-p-toluenesulfonamide. The solvent is isopropyl alcohol. The concentration CON of the sublimable substance in processing solution g is 1.96 [Vol %]. In other words, the volume ratio of compound a to isopropyl alcohol is as follows: compound a:isopropyl=1:50 (volume ratio)

[0177] In the solidified film forming step, the substrate W is rotated at a rotation speed of 1500 rpm for 10 seconds.

[0178] In the sublimation step, the substrate W is rotated at a rotation speed of 1500 rpm while a dry gas is supplied to the substrate W. The sublimation step lasts for 105 seconds.

[0179] The conditions of Example 2 will be explained. In Example 2, the sublimable substance is compound b. Specifically, in Example 2, the sublimable substance is 2-methyl-8-quinolinol. The concentration CON of the sublimable substance in the treatment solution g is 5.88 [Vol %]. In other words, the volume ratio of compound b to isopropyl alcohol is as follows: compound b:isopropyl=1:16 (volume ratio). Other conditions in Example 2 are the same as those in Example 1.

[0180] The conditions of Example 3 will be explained. In Example 3, the sublimable substance is compound c. Specifically, in Example 3, the sublimable substance is N-tert-butylacrylamide. The concentration CON of the sublimable substance in the treatment liquid g is 1.96 [Vol %]. In other words, the volume ratio of compound c to isopropyl alcohol is as follows: compound c: isopropyl = 1:50 (volume ratio). Other conditions in Example 3 are the same as those in Example 1.

[0181] Each of the substrates W processed in Examples 1 to 3 was evaluated by the average collapse rate Ea, which is an index indicating the quality of the processing performed on the substrates W in Examples 1 to 3.

[0182] The average collapse rate Ea is calculated as follows. The average collapse rate Ea is the average value of multiple local collapse rates Ei. The local collapse rate Ei is the collapse rate in a local area Fi. i is any natural number from 1 to NF. The number NF is the number of local areas Fi. The number NF is a natural number equal to or greater than 2. Each local area Fi is a microregion on the substrate W. Each local area Fi is magnified 50,000 times using a scanning electron microscope, for example. Then, the pattern P in each local area Fi is observed. Each convex portion W1 in each local area Fi is evaluated. Each convex portion W1 in each local area Fi is determined. Specifically, it is determined for each convex portion W1 whether or not the convex portion W1 has collapsed. Each convex portion W1 is classified as either a collapsed convex portion W1 or an uncollapsed convex portion W1. Here, the number of convex portions W1 observed in the local area Fi is defined as NAi. The number of collapsed convex portions W1 in the local area Fi is defined as NBi. The number NBi is equal to or less than the number NAi. The local collapse rate Ei is the ratio of the number NBi to the number NAi. The local collapse rate Ei is defined, for example, by the following formula: Ei = NBi / NAi * 100 (%) The average collapse rate Ea is the sum of the local collapse rates Ei divided by the number NF.

[0183] Fig. 11 is a table showing the quality of the processing performed on the substrates W in Examples 1 to 3. Specifically, Fig. 11 shows the average collapse rate Ea in Examples 1 to 3.

[0184] In Example 1, the average collapse rate Ea was 1.23%, in Example 2, the average collapse rate Ea was 4.66%, and in Example 3, the average collapse rate Ea was 3.77%.

[0185] The average collapse rate Ea of Example 1-3 was sufficiently low. Therefore, in Example 1-3, collapse of the pattern P was suitably suppressed. In other words, in Example 1-3, the pattern P was suitably protected. Therefore, in Example 1-3, the substrate W was suitably dried. Specifically, the substrate W was dried while the pattern P formed on the substrate W was suitably protected.

[0186] 8. Effects of the Embodiments The substrate processing method of the embodiments 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 is sublimated. The substrate W is dried by the sublimation of the solidified film K.

[0187] Here, the sublimable substance includes at least one of compounds a to c. Specifically, the sublimable substance includes at least one of N-methyl-p-toluenesulfonamide, 2-methyl-8-quinolinol, and N-tert-butylacrylamide. Therefore, the processing solution g includes at least one of compounds a to c. Therefore, in the solidified film forming step, the solidified film K is suitably formed on the substrate W.

[0188] The solidified film K contains at least one of the compounds a to c. Therefore, in the sublimation step, the solidified film K is appropriately sublimated. That is, in the sublimation step, the substrate W is appropriately dried. Specifically, in the sublimation step, the substrate W is dried while the pattern P formed on the substrate W is suitably protected.

[0189] As described above, according to the present substrate processing method, the substrate W is dried appropriately.

[0190] The solvent is isopropyl alcohol. Isopropyl alcohol dissolves compound a favorably. Isopropyl alcohol dissolves compound b favorably. Isopropyl alcohol dissolves compound c favorably. Therefore, it is easy to use the processing liquid g. It is easy to use a sublimable substance. For example, it is easy to supply the processing liquid g to the substrate W in the processing liquid supply step. It is easy to supply the sublimable substance to the substrate W in the processing liquid supply step. Therefore, the processing liquid g is supplied appropriately to the substrate W. The sublimable substance is supplied appropriately to the substrate W. Therefore, the substrate W is dried more favorably.

[0191] The substrate processing method includes a processing liquid generating step in which a processing liquid g is generated. Therefore, the processing liquid g is preferably prepared. Therefore, it is easier to use the processing liquid g.

[0192] In the treatment liquid generating step, the treatment liquid g is generated by mixing a sublimable substance with a solvent, so that the treatment liquid g can be easily generated.

[0193] In the processing solution production step, the processing solution g is stored in the tank 22. This makes it easy to store the processing solution g, and therefore makes it even easier to use the processing solution g.

[0194] As described above, the solvent is isopropyl alcohol. Therefore, the treatment liquid g is easy to handle. The handling of the treatment liquid g includes at least one of preparing the treatment liquid g, generating the treatment liquid g, storing the treatment liquid g, and using the treatment liquid g. For example, it is easy to prepare the treatment liquid g. For example, it is easy to generate the treatment liquid g. For example, it is easy to store the treatment liquid g. For example, it is easy to use the treatment liquid g.

[0195] The substrate processing apparatus 1 includes a substrate holding unit 13 and a first supply unit 15a. The substrate holding unit 13 holds a substrate W. The first supply unit 15a supplies a processing liquid g to the substrate W held by the substrate holding unit 13. The processing liquid g contains a sublimable substance and a solvent.

[0196] Here, the sublimable substance contains at least one of the compounds a to c. Therefore, the processing solution g contains at least one of the compounds a to c. Therefore, the solidified film K is suitably formed on the substrate W.

[0197] The solidified film K contains at least one of the compounds a to c. Therefore, the solidified film K is appropriately sublimated. That is, the substrate W is appropriately dried. Specifically, the substrate W is dried while the pattern P formed on the substrate W is suitably protected.

[0198] As described above, the substrate processing apparatus 1 allows the substrate W to be dried appropriately.

[0199] The solvent is isopropyl alcohol. As described above, isopropyl alcohol dissolves the compounds a-c favorably. Therefore, it is easy to use the processing liquid g. It is easy to use a sublimable substance. For example, it is easy for the first supply unit 15a to supply the processing liquid g to the substrate W held by the substrate holding unit 13. It is easy for the first supply unit 15a to supply the sublimable substance to the substrate W held by the substrate holding unit 13. Therefore, the processing liquid g is properly supplied to the substrate W. The sublimable substance is properly supplied to the substrate W. Therefore, the substrate W is dried more appropriately.

[0200] The processing liquid g is used to dry the substrate W on which the pattern P is formed. Specifically, the processing liquid g is a drying auxiliary liquid. The processing liquid g contains a sublimable substance and a solvent.

[0201] Here, the sublimable substance contains at least one of the compounds a to c. Therefore, the processing solution g contains at least one of the compounds a to c. Therefore, by supplying the processing solution g to the substrate W, a solidified film K is suitably formed on the substrate W.

[0202] The solidified film K contains at least one of the compounds a to c. Therefore, the solidified film K is appropriately sublimated. That is, the substrate W is appropriately dried. Specifically, the substrate W is dried while the pattern P formed on the substrate W is suitably protected.

[0203] As described above, the substrate W is properly dried using the processing liquid g. The processing liquid g is useful for drying the substrate W.

[0204] The solvent is isopropyl alcohol. As described above, isopropyl alcohol dissolves the compounds a to c favorably. Therefore, it is easy to use the treatment liquid g. It is easy to use a sublimable substance. Therefore, the substrate W is more appropriately dried using the treatment liquid g. The treatment liquid g is more useful for drying the substrate W.

[0205] As described above, the solvent is isopropyl alcohol, which makes the treatment liquid g easy to handle.

[0206] The processing liquid g is supplied to the substrate W. The solvent evaporates from the processing liquid g on the substrate W. A solidified film K containing a sublimable substance is formed on the substrate W. The solidified film K is then sublimated. When the processing liquid g is used in this manner, the substrate W is more appropriately dried. When the processing liquid g is used in these procedures, the processing liquid g is more useful for drying the substrate W.

[0207] 9. Modified Embodiments The present invention is not limited to the embodiments, and can be modified as follows.

[0208] (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.

[0209] 12 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.

[0210] 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.

[0211] The first supply source 19a includes a mixing section 44. The mixing section 44 is connected to the first tank 41 and the second tank 42. The mixing section 44 communicates with the first tank 41 and the second tank 42. The mixing section 44 produces a treatment liquid g. The mixing section 44 is further connected to the first supply section 15a. The mixing section 44 communicates with the first supply section 15a. The mixing section 44 supplies the treatment liquid g to the first supply section 15a.

[0212] Specifically, the mixing section 44 includes pipes 45a and 45b and a joint 46. The pipe 45a is connected to the first tank 41. The pipe 45a communicates with the first tank 41. The pipe 45b is connected to the second tank 42. The pipe 45b communicates with the second tank 42. The joint 46 is connected to the pipes 45a and 45b. The joint 46 communicates with the pipes 45a and 45b. The joint 46 is further connected to the pipe 17a. The joint 46 is further connected to the pipe 17a. The pipes 45a and 45b are connected to the pipe 17a via the joint 46. The pipes 45a and 45b are connected to the pipe 17a via the joint 46.

[0213] The mixing section 44 includes pumps 47a and 47b. The pumps 47a and 47b are respectively provided on the pipes 45a and 45b. The pump 47a sends the sublimable substance from the first tank 41 to the joint 46 through the pipe 45a. The pump 47b sends the solvent from the second tank 42 to the joint 46 through the pipe 45b.

[0214] The mixing unit 44 includes filters 48a and 48b. The filters 48a and 48b are provided on the pipes 45a and 45b, respectively. The sublimable substance passes through the filter 48a. The filter 48a filters the sublimable substance. The solvent passes through the filter 48b. The filter 48b filters the solvent.

[0215] The mixing unit 44 includes valves 49a and 49b. The valves 49a and 49b are provided in the pipes 45a and 45b, respectively. The valve 49a adjusts the flow rate of the sublimable substance flowing through the pipe 45a. The valve 49b adjusts the flow rate of the solvent flowing through the pipe 45b. Each of the valves 49a and 49b may include, for example, a flow rate control valve. Each of the valves 49a and 49b may include, for example, a flow rate control valve and an on-off valve.

[0216] An example of the operation of the first supply source 19a in the modified embodiment will be described. In the treatment liquid supply step, the first supply source 19a generates a treatment liquid g and sends the treatment liquid g to the first supply unit 15a. Specifically, the valves 49a and 49b are opened. The pump 47a sends a sublimable substance from the first tank 41 to the joint 46. The pump 47b sends a solvent from the second tank 42 to the joint 46. The sublimable substance and the solvent are mixed in the joint 46. The sublimable substance and the solvent become the treatment liquid g in the joint 46. Furthermore, the treatment liquid g flows from the joint 46 to the first supply unit 15a. The nozzle 16a ejects the treatment liquid g.

[0217] According to this modified embodiment, there is no need to store the processing liquid g before it is supplied to the first supply unit 15 a. Therefore, the concentration CON of the sublimable substance in the processing liquid g can be controlled with high precision. As a result, the substrate W can be dried more appropriately.

[0218] Furthermore, the first supply source 19a does not include the tank 22. Therefore, the structure of the first supply source 19a is preferably simplified, and the first supply source 19a is preferably miniaturized.

[0219] (2) The substrate processing method of the embodiment includes a chemical liquid supplying step, a rinse liquid supplying step, and a replacement liquid supplying step. However, this is not limited to this. For example, at least one of the chemical liquid supplying step, the rinse liquid supplying step, and the replacement liquid supplying step may be omitted. For example, all of the chemical liquid supplying step, the rinse liquid supplying step, and the replacement liquid supplying step may be omitted.

[0220] (3) In the embodiment, when the processing liquid supplying step was performed, a liquid (e.g., a substitute liquid) was present on the substrate W. In the processing liquid supplying step, the processing liquid g was supplied to the substrate W in a wet state. In other words, in the processing liquid supplying step, the processing liquid g was supplied to the substrate W in a non-dried state. However, this is not limited to this. For example, when the processing liquid supplying step was performed, a liquid (e.g., a substitute liquid) may not be present on the substrate W. For example, in the processing liquid supplying step, the processing liquid g may be supplied to the substrate W in a dry state. In other words, in the processing liquid supplying step, the processing liquid g may be supplied to the substrate W in a non-wet state.

[0221] (4) In the processing liquid supplying step of the embodiment, the processing liquid g removes the substitute liquid from the substrate W. However, this is not limited to this. For example, in the processing liquid supplying step, the processing liquid g may clean the substrate W. For example, in the processing liquid supplying step, the processing liquid g may remove foreign matter adhering to the substrate W. For example, in the processing liquid supplying step, the processing liquid g may dissolve foreign matter adhering to the substrate W. The foreign matter is, for example, resist residue.

[0222] (5) In the solidified film formation process of the embodiment, a dry gas is not supplied to the substrate W. However, this is not limited to this. In the solidified film formation process, a dry gas may be supplied to the substrate W. In the solidified film formation process, a dry gas may be supplied to the processing liquid g on the substrate W. In the solidified film formation process, a dry gas may be supplied to the liquid film G. According to this modified embodiment, in the solidified film formation process, the processing liquid g on the substrate W is exposed to the dry gas. Therefore, in the solidified film formation process, the solvent evaporates efficiently from the processing liquid g on the substrate W. In the solidified film formation process, the solidified film K is efficiently formed on the substrate W.

[0223] (6) In the embodiment, for example, the pattern P on the substrate W may be formed on the substrate W before the processing unit 11 processes the substrate W. Alternatively, the pattern P may be formed on the substrate W when the processing unit 11 processes the substrate W. The pattern P may be formed on the substrate W, for example, in the chemical liquid supplying step (step S12).

[0224] (7) The embodiment and each modified embodiment described above in (1) to (6) may be further modified as appropriate by replacing or combining each configuration with the configuration of another modified embodiment.

[0225] REFERENCE SIGNS LIST 1... substrate processing apparatus 10... control section 11... processing unit 13... substrate holding section 15... supply section 15a... first supply section (processing liquid supply section) 19a... first supply source A... recess g... processing liquid G... liquid film of processing liquid K... solidified film P... pattern W... substrate W1... protrusion

Claims

1. A substrate processing method for processing a substrate on which a pattern has been 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 contains at least one of N-methyl-p-toluenesulfonamide, 2-methyl-8-quinolinol, and N-tert-butylacrylamide.

2. The substrate processing method according to claim 1, wherein the solvent is isopropyl alcohol.

3. A substrate processing apparatus comprising: a substrate holding section that holds a substrate; and a processing liquid supply section that supplies a processing liquid containing a sublimable substance and a solvent to the substrate held by the substrate holding section, wherein the sublimable substance contains at least one of N-methyl-p-toluenesulfonamide, 2-methyl-8-quinolinol, and N-tert-butylacrylamide.

4. The substrate processing apparatus according to claim 3, wherein the solvent is isopropyl alcohol.

5. A treatment liquid used for drying a substrate on which a pattern has been formed, the treatment liquid comprising: a sublimable substance; and a solvent, the sublimable substance comprising at least one of N-methyl-p-toluenesulfonamide, 2-methyl-8-quinolinol, and N-tert-butylacrylamide.

6. The treatment liquid according to claim 5, wherein the solvent is isopropyl alcohol.

7. A processing liquid according to claim 5, wherein the processing liquid is supplied to the substrate, the solvent is evaporated from the processing liquid on the substrate, a solidified film containing the sublimable substance is formed on the substrate, and then the solidified film is sublimated.

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