Substrate processing method

Abstract

The invention provides a substrate processing method capable of properly processing a substrate. The present invention relates to a substrate processing method for processing a substrate (W). The substrate processing method includes a developing step, a processing liquid supply step, a cured film formation step, and a sublimation step. In the developing step, a developing solution (53) is supplied to the substrate (W). In the processing liquid supply step, a processing liquid (55) is supplied to the substrate (W). The treatment liquid (55) contains a sublimable substance and a solvent. In the cured film forming step, the solvent of the processing liquid evaporates from the processing liquid (55) on the substrate (W). In the cured film forming step, a cured film (57) is formed on the substrate (W). The cured film (57) contains a sublimable substance. In the sublimation step, the cured film (57) is sublimated.

Description

TECHNICAL FIELD

[0001] The present application relates to a substrate processing method. The substrate is, for example, a semiconductor wafer, a substrate for liquid crystal display, a substrate for organic EL (Electroluminescence), a substrate for FPD (Flat Panel Display), a substrate for optical display, a substrate for magnetic disk, a substrate for optical disk, a substrate for optical magnetic disk, a substrate for photomask, or a substrate for solar cell. BACKGROUND

[0002] Japanese Patent Application Publication No. 2021-9988 discloses a substrate processing method for processing a substrate. Specifically, the substrate processing method of Japanese Patent Application Publication No. 2021-9988 includes a treatment liquid supplying step, a solidified film forming step, and a sublimation step. In the treatment liquid supplying step, a treatment liquid is supplied to the substrate. The treatment liquid contains a solvent and a sublimation substance. In the solidified film forming step, the solvent is evaporated, and a solidified film is formed on the substrate. In the sublimation step, the solidified film is sublimated. Specifically, the solidified film changes from a liquid to a gas without passing through a liquid phase. The substrate is dried. SUMMARY

[0003] PROBLEMS TO BE SOLVED BY THE INVENTION

[0004] Even with the conventional substrate processing method, the substrate is not always properly processed. For example, even with the conventional substrate processing method, the substrate is not always properly dried.

[0005] The present application has been achieved in view of such circumstances, and has an object to provide a substrate processing method capable of properly processing a substrate.

[0006] METHOD FOR SOLVING THE PROBLEMS

[0007] To achieve such an object, the present application adopts the following configuration. That is, the present application is a substrate processing method for processing a substrate, including a developing step, a treatment liquid supplying step, a solidified film forming step, and a sublimation step; a developing liquid is supplied to the substrate in the developing step; a treatment liquid containing a sublimation substance and a solvent is supplied to the substrate in the treatment liquid supplying step; the solvent is evaporated from the treatment liquid on the substrate in the solidified film forming step, thereby forming a solidified film containing the sublimation substance on the substrate; and the solidified film is sublimated in the sublimation step. In other words, the present application is a substrate processing method for processing a substrate, including supplying a developing liquid to the substrate, supplying a treatment liquid containing a sublimation substance and a solvent to the substrate, evaporating the solvent from the treatment liquid on the substrate, thereby forming a solidified film containing the sublimation substance on the substrate, and sublimating the solidified film.

[0008] A substrate processing method is used to process a substrate. The substrate processing method includes a developing step, a processing solution supply step, a curing film formation step, and a sublimation step. In the developing step, a developing solution is supplied to the substrate. In the processing solution supply step, a processing solution is supplied to the substrate. The processing solution contains a sublimable substance and a solvent. In the curing film formation step, the solvent evaporates from the processing solution on the substrate. In the curing film formation step, a curing film is formed on the substrate. The curing film contains a sublimable substance. In the sublimation step, the curing film is sublimated. Through the sublimation of the curing film, the substrate is dried.

[0009] As described above, this substrate processing method includes a developing step. Therefore, according to this substrate processing method, the substrate can be appropriately processed. Specifically, according to this substrate processing method, a developing solution is supplied to the substrate, and then the substrate is appropriately dried.

[0010] In the above-described substrate processing method, it is preferable to perform the processing solution supply step after the developing step, the curing film formation step after the processing solution supply step, and the sublimation step after the curing film formation step. In other words, it is preferable to perform the processing solution supply operation after the developing solution supply operation, the curing film formation operation after the processing solution supply operation, and the curing film sublimation operation after the curing film formation operation. Therefore, the substrate processing method can appropriately process the substrate.

[0011] In the above-described substrate processing method, it is preferable to form a resist pattern on the substrate during the developing step. In other words, it is preferable to form the resist pattern on the substrate by supplying the developing solution. Therefore, the substrate has a resist pattern during the processing solution supply step, the curing film formation step, and the sublimation step. During the processing solution supply step, processing solution is supplied to the substrate having the resist pattern. Even when the substrate has a resist pattern, the substrate can be properly processed during the processing solution supply step, the curing film formation step, and the sublimation step. For example, during the processing solution supply step, the curing film formation step, and the sublimation step, the substrate is dried while appropriately protecting the resist pattern. Moreover, this substrate processing method has a significant effect when the resist pattern is formed on the substrate during the developing step.

[0012] In the above-described substrate processing method, it is preferable that the resist pattern comprises a metal oxide. Therefore, the substrate is processed more appropriately in the processing solution supply step, the curing film formation step, and the sublimation step. For example, in the processing solution supply step, the curing film formation step, and the sublimation step, the substrate is dried while the resist pattern is more appropriately protected.

[0013] In the above-described substrate processing method, the sublimable substance preferably includes at least one of cyclohexanone oxime and camphor. Therefore, the substrate is appropriately processed in the processing solution supply step, the curing film formation step, and the sublimation step. For example, the substrate is appropriately dried in the processing solution supply step, the curing film formation step, and the sublimation step.

[0014] In the above-described substrate processing method, the solvent preferably includes isopropanol. Therefore, the substrate is appropriately processed in the processing solution supply step, the curing film formation step, and the sublimation step. For example, the substrate is appropriately dried in the processing solution supply step, the curing film formation step, and the sublimation step.

[0015] In the above-described substrate processing method, it is preferable to include a displacement step of supplying a displacement solution to the substrate after the development step and before the processing solution supply step. In other words, it is preferable to supply a displacement solution to the substrate after supplying the developer and before supplying the processing solution. Therefore, in the displacement step, the developer on the substrate is replaced with the displacement solution. That is, in the displacement step, the developer is removed from the substrate. Consequently, the processing solution is appropriately supplied to the substrate in the processing solution supply step.

[0016] In the above-described substrate processing method, it is preferable that the displacement liquid has the same composition as the solvent. Therefore, the displacement liquid has a high affinity for the processing liquid. Consequently, in the processing liquid supply step, the processing liquid is more appropriately supplied to the substrate.

[0017] In the above-described substrate processing method, it is preferable to include an exposure step for exposing the substrate before the development step. In other words, it is preferable to expose the substrate before supplying the developer. Even when the substrate is exposed during the exposure step, the substrate is properly processed. Moreover, when the substrate processing method includes an exposure step, this substrate processing method exhibits significant advantages.

[0018] In the above-described substrate processing method, it is preferable that the substrate is exposed to extreme ultraviolet light during the exposure process. In other words, it is preferable to expose the substrate to extreme ultraviolet light by exposing it to the above-described exposure process. Therefore, the substrate is processed more appropriately.

[0019] In the above-described substrate processing method, it is preferable to transfer the pattern onto the resist film on the substrate during the exposure step. In other words, it is preferable to transfer the pattern onto the resist film by exposing the substrate. Therefore, it is easy to form a resist pattern on the substrate during the development step. As described above, even if the resist pattern is formed on the substrate during the development step, the substrate can be appropriately processed during the solution supply step, the curing film formation step, and the sublimation step.

[0020] In the above-described substrate processing method, it is preferable to include a first heating step of heating the substrate after the exposure step and before the development step. In other words, it is preferable to heat the substrate after exposure and before supplying the developer. Therefore, in the development step, the substrate is appropriately developed.

[0021] In the above-described substrate processing method, it is preferable to include a resist film forming step, which involves forming a resist film on the substrate, before the exposure step. In other words, it is preferable to form a resist film on the substrate before exposing the substrate. Even when the resist film is formed on the substrate during the resist film forming step, the substrate can be properly processed. Moreover, when the substrate processing method includes a resist film forming step, this substrate processing method exhibits significant advantages.

[0022] In the above-described substrate processing method, it is preferable that the resist film comprises a metal oxide. Therefore, the substrate is processed more appropriately. For example, the substrate is dried more appropriately in the processing solution supply step, the curing film formation step, and the sublimation step.

[0023] In the above-described substrate processing method, it is preferable to include a second heating step of heating the substrate after the resist film formation step and before the exposure step. In other words, it is preferable to heat the substrate after the formation of the resist film and before the exposure of the substrate. Therefore, the substrate is processed more appropriately in the exposure and development steps. Attached Figure Description

[0024] Although several preferred embodiments have been illustrated for the purpose of explaining the invention, it should be understood that the invention is not limited to the configurations and countermeasures shown in the illustrations.

[0025] Figure 1 This is a top view showing the interior of the substrate processing apparatus according to the embodiment.

[0026] Figure 2 This is a side view showing the configuration of one side of the substrate processing apparatus.

[0027] Figure 3 This is a flowchart illustrating the steps of a substrate processing method.

[0028] Figure 4 This is a schematic diagram showing a portion of a substrate during the resist film formation process.

[0029] Figure 5 This is a schematic diagram showing a portion of the substrate during the exposure process.

[0030] Figure 6 This is a schematic diagram showing a portion of the substrate during the development process.

[0031] Figure 7 This is a schematic diagram showing a portion of the substrate during the replacement process.

[0032] Figure 8 This is a schematic diagram showing a portion of a substrate during the liquid supply process.

[0033] Figure 9 This is a schematic diagram showing a portion of a substrate during the curing film formation process.

[0034] Figure 10 This is a schematic diagram showing a portion of a substrate during the curing film formation process.

[0035] Figure 11 This is a schematic diagram showing a portion of the substrate during the sublimation process.

[0036] Figure 12 This is a schematic diagram showing a portion of the substrate during the sublimation process.

[0037] Figure 13 This is a graph showing the evaluation of the substrates processed in the embodiments and the substrates processed in the comparative examples.

[0038] Explanation of reference numerals in the attached figures

[0039] 1…substrate processing apparatus, 5…processing section, 9…exposure machine, 13…processing unit (processing unit for resist film formation process), 14…processing unit (processing unit for second heating process), 15…processing unit (processing unit for first heating process), 16…processing unit (processing unit for development process, displacement process, processing solution supply process, curing film formation process and sublimation process), 51…resist film, 51a…exposure section, 51b…non-exposure section, 52…resist pattern, 52a…convex portion, 52b…recessed portion, 53…developer, 54…displacement solution, 55…processing solution, 56…liquid film, 57…curing film, CD…critical dimension, E…defect rate, W…substrate. Detailed Implementation

[0040] Hereinafter, the substrate processing method of the present invention will be described with reference to the accompanying drawings.

[0041] <1. Overview of the substrate processing apparatus>

[0042] Figure 1This is a top view showing the interior of the substrate processing apparatus 1 according to the embodiment. The substrate processing apparatus 1 processes the substrate W. The substrate W is, for example, a semiconductor wafer, a liquid crystal display substrate, an organic EL (electroluminescence) substrate, an FPD (flat panel display) substrate, an optical display substrate, a magnetic disk substrate, an optical disc substrate, an 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 generally circular shape when viewed from above.

[0043] The substrate processing apparatus 1 includes a transfer unit 3 and a processing unit 5. The processing unit 5 is disposed to the side of the transfer unit 3. The processing unit 5 is connected to the transfer unit 3. The processing unit 5 is connected to an exposure machine 9. The transfer unit 3 transports the substrate W to the processing unit 5. The processing unit 5 processes the substrate W. The exposure machine 9 exposes the substrate W. The exposure machine 9 may be an element of the substrate processing apparatus 1. Alternatively, the exposure machine 9 may not be an element of the substrate processing apparatus 1.

[0044] The transport unit 3 has multiple (e.g., four) carrier placement units 11. Each carrier placement unit 11 holds a carrier C. The carrier C contains multiple substrates W. The carrier C is, for example, a FOUP (Front Opening Unified Pod), SMIF (Standard Mechanical Interface), or OC (Open Cassette).

[0045] The transfer unit 3 includes a conveying mechanism 12. The conveying mechanism 12 conveys the substrate W between the carrier C placed in the carrier placement unit 11 and the processing unit 5. The conveying mechanism 12 is, for example, a conveying robot.

[0046] The processing unit 5 includes multiple processing units 13, 14, 15, and 16. Processing units 13 to 16 respectively process the substrate W. For example, processing unit 13 forms a resist film on the substrate W. Processing unit 14 heats the substrate W. Processing unit 15 heats the substrate W. Processing unit 16 supplies developing solution to the substrate W. Processing units 13, 14, 15, and 16 are, in other words, processing chambers 13, 14, 15, and 16.

[0047] The processing unit 5 includes a transfer mechanism 17. The transfer mechanism 17 transfers the substrate W to the transfer mechanism 12. The transfer mechanism 17 transfers the substrate W to the processing units 13-16. Furthermore, the transfer mechanism 17 transfers the substrate W to the exposure machine 9. The transfer mechanism 17 is, for example, a transfer robot.

[0048] The substrate processing apparatus 1 may also include an interface section (not shown). The interface section is disposed between the processing unit 5 and the exposure machine 9. The interface section transports the substrate W between the processing unit 5 and the exposure machine 9.

[0049] Here is a brief explanation of the operation of the substrate processing apparatus 1. The transfer mechanism 12 transfers the substrate W from the carrier C to the transfer mechanism 17.

[0050] The transfer mechanism 17 transfers the substrate W from the transfer mechanism 12 to the processing unit 13. The processing unit 13 forms a resist film on the substrate W. The transfer mechanism 17 transfers the substrate W from the processing unit 13 to the processing unit 14. The processing unit 14 heats the substrate W. The transfer mechanism 17 transfers the substrate W from the processing unit 14 to the exposure machine 9.

[0051] Exposure machine 9 exposes substrate W.

[0052] The transfer mechanism 17 transfers substrate W from exposure machine 9 to processing unit 15. Processing unit 15 heats substrate W. Transfer mechanism 17 transfers substrate W from processing unit 15 to processing unit 16. Processing unit 16 supplies developing solution to substrate W. Transfer mechanism 17 transfers substrate W from processing unit 16 to transfer mechanism 12.

[0053] The transfer mechanism 12 transfers the substrate W from the transfer mechanism 17 to the carrier C.

[0054] <2. Example of the configuration of the processing unit and exposure machine>

[0055] Figure 2 This is a side view showing the configuration of one side of the substrate processing apparatus 1. Figure 2 For convenience, processing units 13 to 16 are arranged on one side of the substrate processing apparatus 1. However, the arrangement of processing units 13 to 16 can be changed appropriately.

[0056] The processing unit 13 will be described below. The processing unit 13 includes a substrate holding section 21. The substrate holding section 21 holds a substrate W in a generally horizontal position.

[0057] The processing unit 13 includes a rotation drive unit 22. The rotation drive unit 22 is connected to the substrate holding unit 21. The rotation drive unit 22 rotates the substrate holding unit 21. The substrate W held by the substrate holding unit 21 rotates integrally with the substrate holding unit 21. The rotation drive unit 22 includes, for example, an electric motor.

[0058] The processing unit 13 includes a nozzle 23. The nozzle 23 supplies resist film material to the substrate W held by the substrate holding part 21.

[0059] This describes the resist film material supplied by nozzle 23. The resist film material may be classified as, for example, a negative resist film material.

[0060] The photoresist film material contains metal oxides. Photoresist film materials are also known as "metal oxide photoresists". Metal oxides include, for example, at least one of tin oxide, hafnium oxide, zinc oxide, and zirconium oxide.

[0061] For example, resist film materials comprise complexes of metal oxides. These metal oxide complexes comprise a metal oxide core and ligands (ligands). The metal oxide core is bound to the ligands. The metal oxide core is surrounded by the ligands. The ligands comprise at least one of organic compounds and resins.

[0062] The resist film material contains a solvent. The solvent of the resist film material is, for example, an organic solvent. The solvent of the resist film material may include, for example, at least one of propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME).

[0063] The processing unit 14 will be described. The processing unit 14 includes a heating plate 25. The heating plate 25 extends in a horizontal direction. A substrate W is placed on the heating plate 25. The heating plate 25 supports a substrate W in a horizontal position.

[0064] The processing unit 14 includes a heater 26. The heater 26 is mounted on a heating plate 25. The heater 26 heats the substrate W on the heating plate 25.

[0065] The processing unit 15 will be described. The processing unit 15 has a configuration similar to that of the processing unit 14. The processing unit 15 includes a heating plate 28. The heating plate 28 extends in a horizontal direction. A substrate W is placed on the heating plate 28. The heating plate 28 supports a substrate W in a horizontal orientation.

[0066] The processing unit 15 includes a heater 29. The heater 29 is mounted on a heating plate 28. The heater 29 heats the substrate W on the heating plate 28.

[0067] The processing unit 16 will be described below. The processing unit 16 includes a substrate holding section 31. The substrate holding section 31 holds a substrate W in a generally horizontal position.

[0068] The processing unit 16 includes a rotation drive unit 32. The rotation drive unit 32 is connected to the substrate holding unit 31. The rotation drive unit 32 rotates the substrate holding unit 31. The substrate W held by the substrate holding unit 31 rotates integrally with the substrate holding unit 31. The rotation drive unit 32 includes, for example, an electric motor.

[0069] The processing unit 16 includes nozzles 33, 34, 35, and 36. Nozzle 33 supplies developing solution to the substrate W held by the substrate holding section 31. Nozzle 34 supplies replacement solution to the substrate W held by the substrate holding section 31. Nozzle 35 supplies processing solution to the substrate W held by the substrate holding section 31. Nozzle 36 supplies drying gas to the substrate W held by the substrate holding section 31.

[0070] The developer supplied by nozzle 33 will be described. The developer is, for example, classified as a solvent developer.

[0071] The developer may contain, for example, at least one of acetic acid, butyl acetate, 2-heptanone, and propylene glycol monomethyl ether acetate (PGMEA). The developer may be, for example, a mixture of propylene glycol monomethyl ether acetate (PGMEA) and acetic acid.

[0072] The displacement fluid supplied by nozzle 34 is described below. The displacement fluid may contain, for example, an organic solvent. The displacement fluid may contain, for example, an alcohol. The displacement fluid may contain, for example, isopropanol (IPA).

[0073] The processing fluid supplied by nozzle 35 is described. The processing fluid contains a sublimable substance. The sublimable substance is sublimable. "Sublimability" refers to the property of a monomer, compound, or mixture to change from a solid phase to a gas or from a gas phase to a solid without passing through a liquid.

[0074] Sublimable substances include, for example, at least one of cyclohexanone oxime and camphor.

[0075] The processing solution contains a solvent. The solvent of the processing solution is, for example, a liquid. The solvent of the processing solution dissolves sublimable substances. The sublimable substances in the processing solution dissolve in the solvent. That is, the processing solution contains a solvent and sublimable substances dissolved in the solvent. The sublimable substances are equivalent to the solute of the processing solution.

[0076] The solvent in the treatment solution is volatile. For example, the solvent in the treatment solution can change from a liquid to a gas. The solvent in the treatment solution can evaporate from a liquid.

[0077] The solvent of the treatment solution preferably has the same composition as that of the replacement solution.

[0078] The solvent of the treatment solution may include, for example, an organic solvent. The solvent of the treatment solution may include, for example, an alcohol. The solvent of the treatment solution may include, for example, isopropanol (IPA).

[0079] The dry gas supplied by nozzle 36 is described below. The dry gas is, for example, at least one of air and an inert gas. Air is, for example, compressed air. An inert gas is, for example, nitrogen. The dry gas preferably has a dew point lower than room temperature.

[0080] The processing unit 16 processes the substrate W under normal pressure. The processing solution is used under normal pressure.

[0081] Atmospheric pressure includes standard atmospheric pressure (1 atmosphere, 101325 Pa). Atmospheric pressure is, for example, the air pressure in the range of 0.7 atmospheres or more and 1.3 atmospheres or less. In this specification, pressure values ​​are expressed as absolute pressure relative to absolute vacuum.

[0082] The processing unit 16 processes the substrate W at room temperature. The processing solution is used at room temperature.

[0083] Here, ambient temperature includes room temperature. Ambient temperature is, for example, a temperature in the range of 5°C to 35°C. Ambient temperature is, for example, a temperature in the range of 10°C to 30°C. Ambient temperature is, for example, a temperature in the range of 20°C to 25°C.

[0084] The exposure machine 9 will be described below. The exposure machine 9 includes a stage 41. The stage 41 extends horizontally. A substrate W is placed on the stage 41. The stage 41 supports a substrate W in a horizontal orientation.

[0085] Exposure machine 9 has a photomask 42. The photomask 42 is also called a reticle. The photomask 42 is positioned above the stage 41. The photomask 42 has a pattern.

[0086] The exposure machine 9 includes a light source 43. The light source 43 is positioned above the photomask 42. The light source 43 illuminates the substrate W on the stage 41. Only the light passing through the photomask 42 reaches the substrate W. Thus, the pattern of the photomask 42 is transferred onto the substrate W.

[0087] Light source 43, for example, irradiates with extreme ultraviolet light. In this specification, extreme ultraviolet light is appropriately abbreviated as "EUV light". EUV light, for example, has a wavelength of 13.5 nm.

[0088] <3. Substrate Processing Method>

[0089] See Figures 2-3 . Figure 3 This is a flowchart illustrating the steps of a substrate processing method. The substrate processing method is used to process substrate W. The substrate processing method includes a resist film formation step, a second heating step, an exposure step, a first heating step, a development step, a displacement step, a processing solution supply step, a curing film formation step, and a sublimation step.

[0090] <Step S1> Resist film formation process

[0091] In the processing unit 13, a resist film is formed on the substrate W.

[0092] Specifically, the substrate holding section 21 holds the substrate W. The rotation drive section 22 rotates the substrate W. The nozzle 23 supplies resist film material to the substrate W. The resist film material contains metal oxide.

[0093] Figure 4 This diagram schematically illustrates a portion of a substrate W during the resist film formation process. A resist film 51 is formed on the substrate W. The resist film 51 is composed of a resist film material. For example, the resist film 51 is classified as a negative resist film. The resist film 51 contains a metal oxide.

[0094] <Step S2> Second heating process

[0095] After the resist film formation process, a second heating process is performed. In processing unit 14, substrate W is heated. For example, substrate W is heated at a temperature between 100 and 150 degrees Celsius.

[0096] Specifically, the substrate W is placed on the heating plate 25. The heater 26 heats the substrate W on the heating plate 25.

[0097] In the second heating process, the solvent in the resist film 51 evaporates. The solvent content in the resist film 51 decreases.

[0098] <Step S3> Exposure process

[0099] After the second heating process, an exposure process is performed. In the exposure machine 9, the substrate W is exposed. That is, the resist film 51 on the substrate W is exposed.

[0100] Specifically, substrate W is placed on stage 41. Light source 43 illuminates the substrate W. The pattern of photomask 42 is transferred onto resist film 51 on substrate W.

[0101] For example, light source 43 illuminates EUV light. The substrate W on the stage 41 is exposed to EUV light.

[0102] Figure 5 This diagram schematically illustrates a portion of the substrate W during the exposure process. Light reaches the substrate W on the stage 41 only through the photomask 42.

[0103] For example, before the exposure process, the resist film 51 is soluble in the developer. After the exposure process, the resist film 51 has an exposed portion 51a and a non-exposed portion 51b. The exposed portion 51a is the portion of the resist film 51 that is exposed. The exposed portion 51a changes from soluble to insoluble. The non-exposed portion 51b is the portion of the resist film 51 that is not exposed. The non-exposed portion 51b remains soluble.

[0104] More specifically, the resist film 51 comprises a metal oxide. In the exposed portion 51a, the bonds between the metal oxide nucleus and ligands are broken. The metal oxide nucleus and ligands separate from each other. Moreover, the nuclei of multiple metal oxides bond together. For example, the nuclei of multiple metal oxides condense together. Therefore, the exposed portion 51a changes from soluble to insoluble. In the non-exposed portion 51b, the bonds between the metal oxide nucleus and ligands are not broken. Therefore, the non-exposed portion 51b remains soluble.

[0105] <Step S4> First heating process

[0106] After the exposure process, a first heating process is performed. In the processing unit 15, the substrate W is heated. For example, the substrate W is heated at a temperature between 130 degrees and 250 degrees. For example, the substrate W is heated at a temperature between 180 degrees and 200 degrees.

[0107] Specifically, the substrate W is placed on the heating plate 28. The heater 29 heats the substrate W on the heating plate 28.

[0108] During the first heating process, the insolubility of the exposure section 51a increases. The exposure section 51a becomes even less soluble in the developing solution.

[0109] <Step S5>Developing process

[0110] After the first heating process, a developing process is performed. In the processing unit 16, developing solution is supplied to the substrate W.

[0111] Specifically, the substrate holding section 31 holds the substrate W. The rotation drive section 32 rotates the substrate W. The nozzle 33 supplies developing solution to the substrate W.

[0112] Figure 6 This is a schematic diagram showing a portion of substrate W during the developing process. Developer 53 is supplied to substrate W. Figure 6 The resist film 51 is not shown, but it is developed by the developer 53. Specifically, the non-exposed portion 51b is removed from the substrate W by the developer 53. The exposed portion 51a remains on the substrate W.

[0113] In the developing process, a resist pattern 52 is formed on the substrate W. The resist pattern 52 includes a raised portion 52a and a recessed portion 52b. The raised portion 52a is formed by an exposed portion 51a. The recessed portion 52b is a space. The recessed portion 52b is located at the same position as the non-exposed portion 51b. The recessed portion 52b is formed to the side of the raised portion 52a.

[0114] The resist pattern 52 contains a metal oxide. The protrusion 52a contains a metal oxide.

[0115] <Step S6> Replacement process

[0116] After the development process, a replacement process is performed. In the processing unit 16, a replacement solution is supplied to the substrate W.

[0117] Specifically, the substrate holding section 31 holds the substrate W. The rotation drive section 32 rotates the substrate W. The nozzle 34 supplies a displacement liquid to the substrate W. The displacement liquid, for example, has the same composition as the solvent in the processing liquid. The displacement liquid, for example, contains isopropanol.

[0118] Figure 7 This diagram schematically illustrates a portion of substrate W during the replacement process. The developer 53 on substrate W is replaced with replacement solution 54. The developer 53 is then removed from substrate W.

[0119] <Step S7> Processing fluid supply procedure

[0120] After the replacement process, a processing liquid supply process is performed. In the processing unit 16, processing liquid is supplied to the substrate W.

[0121] Specifically, in the processing unit 16, the substrate holding section 31 holds the substrate W. The rotation drive section 32 rotates the substrate W. The nozzle 35 supplies processing liquid to the substrate W. The processing liquid contains a sublimable substance and a solvent. The sublimable substance includes, for example, at least one of cyclohexanone oxime and camphor. The solvent of the processing liquid includes isopropanol.

[0122] Figure 8 This diagram schematically illustrates a portion of a substrate W during the processing liquid supply process. Processing liquid 55 is supplied to a substrate W having a resist pattern 52. Displacement liquid 54 on the substrate W is replaced with processing liquid 55. Displacement liquid 54 is removed from the substrate W.

[0123] The processing liquid 55 on the substrate W is referred to as "liquid film 56". During the processing liquid supply process, liquid film 56 is formed. During the processing liquid supply process, liquid film 56 covers the substrate W. During the processing liquid supply process, liquid film 56 covers resist pattern 52.

[0124] During the processing fluid supply step, the resist pattern 52 is completely immersed in the liquid film 56. The protrusions 52a are immersed in the liquid film 56. The recesses 52b are filled with the liquid film 56.

[0125] The liquid film 56 is in contact with the gas G. Specifically, the liquid film 56 has an upper surface 56a. The upper surface 56a is in contact with the gas G. The upper surface 56a corresponds to the gas-liquid interface between the liquid film 56 and the gas G.

[0126] In the liquid supply process, the upper surface 56a is located at a higher position than the resist pattern 52. The resist pattern 52 does not intersect with the upper surface 56a. The resist pattern 52 does not intersect with the gas-liquid interface between the liquid film 56 and the gas G. Therefore, the resist pattern 52 does not bear the surface tension of the liquid film 56.

[0127] In the liquid supply process, the upper surface 56a is located at a higher position than the protrusion 52a. The protrusion 52a does not intersect with the upper surface 56a. The protrusion 52a does not intersect with the gas-liquid interface between the liquid film 56 and the gas G. Therefore, the protrusion 52a does not bear the surface tension of the liquid film 56.

[0128] <Step S8> Curing film formation process

[0129] Following the processing liquid supply process, a curing film formation process is performed. In processing unit 16, the solvent of processing liquid 55 evaporates from processing liquid 55 on substrate W. A curing film is formed on substrate W. The curing film contains a sublimable material.

[0130] Specifically, the substrate holding part 31 holds the substrate W. The rotation driving part 32 rotates the substrate W.

[0131] Figure 9 This diagram schematically illustrates a portion of the substrate W during the curing film formation process. As described above, the solvent in the processing liquid 55 is volatile. Therefore, during the curing film formation process, the solvent in the liquid film 56 evaporates smoothly.

[0132] Soon, the sublimable substance in the liquid film 56 begins to precipitate on the substrate W. That is, the sublimable substance changes from a solute in the processing liquid 55 to a solid phase of sublimable substance. The solid phase of sublimable substance forms a solidified film 57. Through the precipitation of the sublimable substance, the liquid film 56 gradually transforms into a solidified film 57.

[0133] The cured film 57 contains no solvent. The cured film 57 is a solid. The cured film 57 is formed on the substrate W.

[0134] For example, the upper part of the liquid film 56 first becomes the cured film 57. For example, the upper part of the liquid film 56 becomes the cured film 57 before the lower part of the liquid film 56 becomes the cured film 57. At this time, the cured film 57 is located above the liquid film 56. The cured film 57 covers the upper surface 56a of the liquid film 56.

[0135] When the cured film 57 covers the entire upper surface 56a, the cured film 57 separates the liquid film 56 from the gas G. The liquid film 56 is not in contact with the gas G. The upper surface 56a no longer functions as a gas-liquid interface. The gas-liquid interface between the liquid film 56 and the gas G disappears.

[0136] After the gas-liquid interface between the liquid film 56 and the gas G disappears, the resist pattern 52 no longer bears the surface tension of the liquid film 56. After the gas-liquid interface between the liquid film 56 and the gas G disappears, the protrusion 52a no longer bears the surface tension of the liquid film 56.

[0137] For example, the upper surface 56a is lowered to the same height as the resist pattern 52. Alternatively, the upper surface 56a is lowered to the same height as the protrusion 52a. In this case, the upper surface 56a intersects with the resist pattern 52. The upper surface 56a intersects with the protrusion 52a.

[0138] As described above, the upper surface 56a no longer corresponds to a gas-liquid interface. Therefore, even when the upper surface 56a intersects with the resist pattern 52, the resist pattern 52 will not bear the surface tension of the liquid film 56. Even when the upper surface 56a intersects with the protrusion 52a, the protrusion 52a will not bear the surface tension of the liquid film 56. Therefore, the liquid film 56 will not exert a meaningful force on the resist pattern 52, and the liquid film 56 will decrease. The liquid film 56 will not exert a meaningful force on the protrusion 52a, and the liquid film 56 will decrease.

[0139] Figure 10 This is a schematic diagram showing a portion of the substrate W during the curing film formation process. Figure 10 The diagram schematically shows, for example, the substrate W at the end of the curing film formation process. At the end of the curing film formation process, all the liquid film 56 disappears from the substrate W. At the end of the curing film formation process, no liquid film 56 remains on the substrate W.

[0140] At the end of the curing film formation process, only the curing film 57 remains on the substrate W. The recess 52b is filled with the curing film 57. The curing film 57 is in contact with the resist pattern 52. The curing film 57 supports the resist pattern 52. The curing film 57 protects the resist pattern 52. For example, the curing film 57 prevents the resist pattern 52 from collapsing.

[0141] The cured film 57 contacts the protrusion 52a. The cured film 57 supports the protrusion 52a. The cured film 57 protects the protrusion 52a. For example, the cured film 57 prevents the protrusion 52a from collapsing.

[0142] <Step S9> Sublimation Process

[0143] After the curing film formation process, a sublimation process is performed. In the processing unit 16, the curing film 57 on the substrate W is sublimated.

[0144] Specifically, the substrate holding section 31 holds the substrate W. The rotation drive section 32 rotates the substrate W. The nozzle 36 supplies drying gas to the substrate W.

[0145] The dry gas promotes the sublimation of the cured film 57. The cured film 57 changes into gas without passing through a liquid state. The cured film 57 is removed from the substrate W through sublimation.

[0146] Figure 11This diagram schematically illustrates a portion of the substrate W during the sublimation process. As the cured film 57 sublimates, it gradually diminishes. The resist pattern 52 begins to be exposed to the gas G. The protrusions 52a begin to be exposed to the gas G.

[0147] During the sublimation of the cured film 57, the cured film 57 does not exert any meaningful force on the resist pattern 52. Since the cured film 57 does not exert any meaningful force on the resist pattern 52, it detaches from the substrate W.

[0148] During the sublimation of the cured film 57, the cured film 57 does not exert a meaningful force on the protrusion 52a. Since the cured film 57 does not exert a meaningful force on the protrusion 52a, the cured film 57 separates from the substrate W.

[0149] During the sublimation of the cured film 57, the cured film 57 does not change into a liquid. Therefore, no liquid is generated on the substrate W during the sublimation process. Therefore, no gas-liquid interface is generated near the resist pattern 52 during the sublimation process. No gas-liquid interface is generated near the protrusion 52a during the sublimation process. Therefore, the resist pattern 52 does not intersect with the gas-liquid interface during the sublimation process. The protrusion 52a does not intersect with the gas-liquid interface during the sublimation process. Therefore, the resist pattern 52 does not experience the surface tension of the liquid during the sublimation process. The protrusion 52a does not experience the surface tension of the liquid during the sublimation process.

[0150] Figure 12 This is a schematic diagram showing a portion of the substrate W during the sublimation process. Figure 12 The diagram schematically shows, for example, the substrate W at the end of the sublimation process. At the end of the sublimation process, all the cured film 57 disappears from the substrate W. At the end of the sublimation process, no cured film 57 remains on the substrate W. At the end of the sublimation process, there is no liquid on the substrate W. The substrate W is dried. Specifically, the entire resist pattern 52 is exposed to the gas G. The entire protrusion 52a is exposed to the gas G. The entire recess 52b is filled only by the gas G.

[0151] Here, the resist pattern 52 includes, for example, at least one of lines, spacing, dots, pillars, and holes. For example, the resist pattern 52 can also be classified as a line and spacing pattern.

[0152] The resist pattern 52 has a critical dimension CD. The critical dimension CD is, for example, the width of the lines included in the resist pattern 52. The critical dimension CD is, for example, the width of the dots included in the resist pattern 52. The critical dimension CD is, for example, the width of the diameter of the dots included in the resist pattern 52. The critical dimension CD is, for example, the width of the pillars included in the resist pattern 52. The critical dimension CD is, for example, the width of the diameter of the pillars included in the resist pattern 52.

[0153] As described above, treatment fluid 55 is used at room temperature. Treatment fluid 55 is used at atmospheric pressure.

[0154] <4. Technical Significance of Substrate Processing Methods>

[0155] The technical significance of the substrate processing method of the embodiments is explained through examples and comparative examples.

[0156] The conditions for the embodiments will be described. In the embodiments, the substrate W is subjected to... Figure 3 The series of processes shown in the embodiment includes a resist film formation process, a second heating process, an exposure process, a first heating process, a development process, a displacement process, a processing solution supply process, a curing film formation process, and a sublimation process. In the resist film formation process, a resist film 51 is formed on the substrate W. The resist film 51 is classified as a negative resist film. The resist film 51 contains a metal oxide. In the exposure process, the substrate W is exposed to EUV light. The result of this series of processes on the substrate W is a substrate W having a resist pattern 52. The resist pattern 52 is classified as a line and spacing pattern.

[0157] In the exposure process, multiple substrates W are exposed with different amounts of light. As a result, in this embodiment, multiple substrates W with different critical dimensions CD are obtained. The critical dimension CD is the width of the lines contained in the resist pattern 52.

[0158] Generally speaking, when the resist film 51 is classified as a negative resist film, the critical size CD increases with the increase of light intensity.

[0159] The conditions for the comparative example will be described. In the comparative example, a series of processes were performed on the substrate W. The series of processes in the comparative example included a spin drying process instead of a displacement process, a processing solution supply process, a curing film formation process, and a sublimation process. Specifically, the series of processes in the comparative example included a resist film formation process, a second heating process, an exposure process, a first heating process, a development process, and a spin drying process. Apart from these, the conditions in the comparative example were the same as those in the embodiment.

[0160] The substrates W processed in the examples and comparative examples were evaluated using a defect rate E. The defect rate E is the number of defects per unit length of the lines in the resist pattern 52. The unit length is 1 mm.

[0161] Figure 13This is a graph showing the evaluation of the substrates processed in the embodiments and the substrates processed in the comparative examples. The horizontal axis is the critical size CD. The vertical axis is the defect rate E. The defect rate E of the embodiments is lower than the defect rate E of the comparative examples. More specifically, when the critical size CD is small, the defect rate E of the embodiments is significantly lower than the defect rate E of the comparative examples. When the critical size CD is in the range of 12nm to 18nm, the defect rate E of the embodiments is significantly lower than the defect rate E of the comparative examples.

[0162] according to Figure 13 The following insights are available. The number of defects in the resist pattern 52 in the embodiment is lower than the number of defects in the resist pattern 52 in the comparative example. Compared with the comparative example, the embodiment suppresses the collapse of the resist pattern 52. In the embodiment, the resist pattern 52 is properly protected compared with the comparative example. In the embodiment, the resist pattern 52 is properly protected, and the substrate W is dried.

[0163] <5. Effects of the Implementation Method>

[0164] The substrate processing method of this embodiment is used to process a substrate. The substrate processing method includes a developing step, a processing solution supply step, a curing film formation step, and a sublimation step. In the developing step, a developing solution 53 is supplied to the substrate W. In the processing solution supply step, a processing solution 55 is supplied to the substrate W. The processing solution 55 contains a sublimable substance and a solvent. In the curing film formation step, the solvent evaporates from the processing solution 55 on the substrate W. In the curing film formation step, a curing film 57 is formed on the substrate W. The curing film 57 contains a sublimable substance. In the sublimation step, the curing film 57 is sublimated. Through the sublimation of the curing film 57, the substrate W is dried.

[0165] As described above, the substrate processing method includes a developing step. Therefore, according to the substrate processing method, the substrate W can be appropriately processed. Specifically, according to the substrate processing method, a developer 53 is supplied to the substrate W, and then the substrate W is appropriately dried.

[0166] After the developing process, a processing solution supply process is performed. After the processing solution supply process, a curing film formation process is performed. After the curing film formation process, a sublimation process is performed. Therefore, the substrate processing method can properly process substrate W.

[0167] In the developing process, a resist pattern 52 is formed on the substrate W. Therefore, the substrate W has the resist pattern 52 in the processing solution supply process, the curing film formation process, and the sublimation process. In the processing solution supply process, processing solution 55 is supplied to the substrate W having the resist pattern 52. Even when the substrate W has the resist pattern 52, the substrate W can be properly processed in the processing solution supply process, the curing film formation process, and the sublimation process. For example, the substrate W is dried while appropriately protecting the resist pattern 52 in the processing solution supply process, the curing film formation process, and the sublimation process. Moreover, when the resist pattern 52 is formed on the substrate W in the developing process, the substrate processing method has a significant effect.

[0168] The resist pattern 52 contains metal oxides. Therefore, the substrate W is treated more appropriately in the processing solution supply process, the curing film formation process, and the sublimation process. For example, in the processing solution supply process, the curing film formation process, and the sublimation process, the substrate W is dried while the resist pattern 52 is more appropriately protected.

[0169] The sublimable substance includes at least one of cyclohexanone oxime and camphor. Therefore, the substrate W is appropriately treated in the processing solution supply process, the curing film formation process, and the sublimation process. For example, the substrate W is appropriately dried in the processing solution supply process, the curing film formation process, and the sublimation process.

[0170] The solvent in the processing solution 55 includes isopropanol. Therefore, the substrate W is properly processed in the processing solution supply process, the curing film formation process, and the sublimation process. For example, the substrate W is properly dried in the processing solution supply process, the curing film formation process, and the sublimation process.

[0171] The substrate processing method includes a displacement step of supplying displacement solution 54 to substrate W. The displacement step is performed after the development step and before the processing solution supply step. Therefore, in the displacement step, the developer 53 on substrate W is replaced with displacement solution 54. That is, in the displacement step, the developer 53 is removed from substrate W. Therefore, in the processing solution supply step, processing solution 55 is appropriately supplied to substrate W.

[0172] As described above, the substrate processing method includes a replacement step. Therefore, after the developer 53 is removed from the substrate W, the processing liquid 55 is supplied to the substrate W. Therefore, the processing liquid 55 does not come into contact with the developer 53. Therefore, the processing liquid 55 does not react with the developer 53. Therefore, in the processing liquid supply step, the processing liquid 55 is appropriately supplied to the substrate W.

[0173] The replacement solution 54 has the same composition as the solvent of the processing solution 55. Therefore, the replacement solution 54 has a high affinity for the processing solution 55. As a result, during the processing solution supply process, the processing solution 55 is supplied to the substrate W more appropriately. For example, it is easier to reduce the consumption of the processing solution 55.

[0174] The substrate processing method includes an exposure step for exposing a substrate W. The exposure step is performed before the development step. Even when the substrate W is exposed during the exposure step, the substrate W is properly processed. Furthermore, when the substrate processing method includes an exposure step, the substrate processing method achieves significant results.

[0175] During the exposure process, substrate W is exposed to extreme ultraviolet light. Therefore, substrate W is treated more appropriately.

[0176] In the exposure process, a pattern is transferred onto the resist film 51 on the substrate W. Therefore, the resist pattern 52 can be easily formed on the substrate W in the development process. As described above, even if the resist pattern 52 is formed on the substrate W in the development process, the substrate W can still be properly processed in the processing solution supply process, the curing film formation process, and the sublimation process.

[0177] The substrate processing method includes a first heating step that heats the substrate. The first heating step is performed after the exposure step and before the development step. Therefore, in the development step, the substrate W is appropriately developed. For example, after the exposure step, the substrate W has an exposure portion 51a. The exposure portion 51a is the portion of the substrate W that was exposed in the exposure step. The first heating step, for example, increases the insolubility of the exposure portion 51a relative to the developing solution. Therefore, in the development step, the exposure portion 51a appropriately remains on the substrate W.

[0178] The substrate processing method includes a resist film forming step for forming a resist film 51 on a substrate W. The resist film forming step is performed before the exposure step. Even when the resist film 51 is formed on the substrate W during the resist film forming step, the substrate W can be properly processed. Moreover, when the substrate processing method includes a resist film forming step, the substrate processing method exhibits significant advantages.

[0179] The resist film 51 contains a metal oxide. Therefore, the substrate W is processed more appropriately. For example, the substrate W is dried more appropriately during the processing solution supply process, the curing film formation process, and the sublimation process.

[0180] The substrate processing method includes a second heating step that heats the substrate. The second heating step is performed after the resist film formation step and before the exposure step. Therefore, the substrate W is processed more appropriately during the exposure and development steps. For example, the second heating step evaporates the solvent in the resist film 51. Therefore, the resist film 51 is appropriately formed on the substrate W. In other words, the resist film 51 is appropriately modified. Therefore, during the exposure step, the resist film 51 on the substrate W is appropriately exposed. During the development step, the resist film 51 on the substrate W is appropriately developed.

[0181] <6. Modified Implementation Methods>

[0182] This invention is not limited to the embodiments described below, and can be implemented in various ways as follows.

[0183] (1) In the substrate processing method of the embodiment, the steps performed before the development step may be appropriately changed. For example, at least one of the resist film formation step, the second heating step, the exposure step, and the first heating step may be omitted.

[0184] (2) In the substrate processing method of the embodiment, the process performed after the development process may be appropriately changed. For example, the replacement process may be omitted.

[0185] (3) In the process of forming the curing film, it is also possible not to supply drying gas to the substrate W.

[0186] Alternatively, during the curing film formation process, a drying gas may be supplied to the substrate W. During the curing film formation process, a drying gas may be supplied to the processing liquid 55 on the substrate W. During the curing film formation process, a drying gas may be supplied to the liquid film 56. According to this modified embodiment, during the curing film formation process, the processing liquid 55 on the substrate W is exposed to the drying gas. Therefore, during the curing film formation process, the solvent in the processing liquid 55 evaporates efficiently. During the curing film formation process, a cured film 57 is efficiently formed on the substrate W.

[0187] (4) Regarding the implementation method and the various modified implementation methods described in (1) to (3) above, the components may be replaced or combined to form other modified implementation methods and so on.

[0188] This invention may be implemented in other specific forms without departing from its idea or essence; therefore, reference should be made to the appended claims rather than the foregoing description to indicate the scope of the invention.

Claims

1. A substrate processing method for processing a substrate, comprising: a developing step of supplying a developing liquid to the substrate; a treatment liquid supplying step of supplying a treatment liquid containing a sublimable substance and a solvent to the substrate; a solidified film forming step of evaporating the solvent from the treatment 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. In the developing step, a resist pattern is formed on the substrate.

2. The substrate processing method according to claim 1, wherein The resist pattern contains a metal oxide.

3. The substrate processing method according to claim 2, wherein The sublimable substance contains at least either of cyclohexanone oxime and camphor.

4. The substrate processing method according to claim 1, wherein The solvent contains isopropyl alcohol.

5. The substrate processing method according to claim 1, wherein After the developing step and before the treatment liquid supplying step, a replacement step of supplying a replacement liquid to the substrate is provided.

6. The substrate processing method of claim 1, wherein, The replacement liquid has the same composition as that of the solvent.

7. The substrate processing method according to claim 6, wherein Before the developing step, an exposure step of exposing the substrate is provided.

8. The substrate processing method of claim 1, wherein, In the exposure step, the substrate is exposed to an extreme ultraviolet.

9. The substrate processing method according to claim 8, wherein In the exposure step, a pattern is transferred to a resist film on the substrate.

10. The substrate processing method according to claim 8, wherein After the exposure step and before the developing step, a first heating step of heating the substrate is provided.

11. The substrate processing method of claim 8, wherein, Before the exposure step, a resist film forming step of forming a resist film on the substrate is provided.

12. The substrate processing method of claim 8, wherein, The resist film contains a metal oxide.

13. The substrate processing method of claim 12, wherein, After the resist film forming step and before the exposure step, a second heating step of heating the substrate is provided.

14. The substrate processing method of claim 12, wherein, ​

Images