Substrate Processing Method and Substrate Processing Apparatus

Abstract

To provide a substrate processing method capable of suppressing destruction of a structure constructing a pattern of a substrate without using an organic solvent when drying the substrate.SOLUTION: In a substrate processing method, a substrate W having a pattern PT containing a plurality of structures 23 is processed. The substrate processing method contains: a suspension supply step S3; a pure water removal step S4; and a particle sublimation step S5. In the suspension supply step S3, a suspension 25 in which a pure water 251 and a plurality of sublimability particles 252 are mixed is supplied onto an upper surface of the substrate W to form a liquid film 26 of the suspension 25 onto the upper surface. In the pure water removal step S4, the pure water 251 is removed from the upper surface of the substrate W so that each sublimability particle 252 remains between the adjacent structure 23 and the structure 23. In the particle sublimation step S5, each sublimability particle 252 remaining between the structure 23 and the structure 23 is sublimated.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present invention relates to a substrate processing method and a substrate processing apparatus.

Background Art

[0002] In the cleaning method described in Patent Document 1, a wafer is held on a rotary mounting portion and rotated at 80 rpm. First, a hydrofluoric acid solution is supplied from a nozzle to the wafer surface, then pure water is supplied from the nozzle to the wafer surface for cleaning, and IPA (isopropyl alcohol) is supplied immediately before the supply of pure water stops. IPA dissolves in pure water, and the pure water is pushed out and completely replaced by IPA due to the Marangoni effect and the centrifugal force due to rotation, whereby the pure water is removed. Thereafter, spin drying is performed by rotating at 300 rpm for 1 second, then at 2000 rpm for 4 seconds, and finally at 4000 rpm for 15 seconds.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the cleaning method described in Patent Document 1, IPA is used when drying the substrate. In addition, when drying the substrate, surface modification of the substrate with a hydrophobizing agent or use of a supercritical fluid may be performed, but IPA is used in any case.

[0005] IPA is effective in suppressing the collapse of structures that make up the uneven pattern of the substrate when drying the substrate. However, trace metals contained in IPA may reduce the quality and reliability of devices obtained from the substrate. For example, when fabricating an image sensor from a substrate, in the drying of deep trenches around the color filter portion of the image sensor, trace metals can cause pixel defects called white spots. Also, considering the impact on the global environment, it is preferable to reduce the usage amount of IPA. IPA is an example of an organic solvent.

[0006] The present invention has been made in view of the above problems, and an object thereof is to provide a substrate processing method and a substrate processing apparatus capable of suppressing the collapse of structures constituting the pattern of a substrate without using an organic solvent when drying the substrate.

Means for Solving the Problems

[0007] According to one aspect of the present invention, in a substrate processing method, a substrate having a pattern including a plurality of structures is processed. The substrate processing method includes a suspension supply step, a pure water removal step, and a particle sublimation step. In the suspension supply step, a suspension in which pure water and a plurality of sublimable particles are mixed is supplied onto the upper surface of the substrate, thereby forming a liquid film of the suspension on the upper surface of the substrate. In the pure water removal step, the pure water is removed from the upper surface of the substrate so that the sublimable particles remain between the adjacent structures. In the particle sublimation step, the sublimable particles remaining between the structures are sublimated.

[0008] In one aspect of the present invention, it is preferable that the hydrogen ion index of the suspension is 4 or less or 9 or more.

[0009] In one aspect of the present invention, it is preferable that the substrate processing method further includes an inert gas supply step. In the inert gas supply step, it is preferable to supply an inert gas onto the upper surface of the substrate in parallel with the particle sublimation step.

[0010] In one aspect of the present invention, the substrate processing method preferably further includes a chemical solution supply step and a rinse solution supply step. In the chemical solution supply step, it is preferable to supply the chemical solution to the upper surface of the substrate before the suspension supply step. In the rinse solution supply step, it is preferable to supply the rinse solution to the upper surface of the substrate after the chemical solution supply step to wash away the chemical solution. The suspension supply step is preferably executed after the rinse solution supply step. In the pure water removal step, it is preferable to remove the pure water from the substrate by rotating the substrate.

[0011] In one aspect of the present invention, the sublimable particles are preferably cyclohexanone oxime, camphor, naphthalene, P-cresol, 1,4-benzoquinone, 2-chloronaphthalene, 4-nitrotoluene, diphenyl ether, or 2,6-dinitrotoluene.

[0012] According to another aspect of the present invention, a substrate processing apparatus processes a substrate having a pattern including a plurality of structures. The substrate processing apparatus includes a substrate holding unit, a suspension supply unit, and a substrate rotating unit. The substrate holding unit holds the substrate. The suspension supply unit forms a liquid film of the suspension on the upper surface of the substrate by supplying a suspension in which pure water and a plurality of sublimable particles are mixed to the upper surface of the substrate. The substrate rotating unit rotates the substrate on which the liquid film is formed by rotating the substrate holding unit.

Advantages of the Invention

[0013] According to the present invention, there can be provided a substrate processing method and a substrate processing apparatus capable of suppressing the collapse of structures constituting a pattern of a substrate without using an organic solvent when drying the substrate.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Mode for Carrying Out the Invention

[0015] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and the description will not be repeated. Also, for convenience of explanation, a three-dimensional orthogonal coordinate system (X, Y, Z) is appropriately shown in the drawings. And in the drawings, the X-axis and the Y-axis are parallel to the horizontal direction, and the Z-axis is parallel to the vertical direction.

[0016] (Embodiment 1) With reference to FIGS. 1 to 8, a substrate processing apparatus 100 and a substrate processing method according to Embodiment 1 of the present invention will be described. First, with reference to FIG. 1, the substrate processing apparatus 100 will be described. FIG. 1 is a plan view showing the inside of the substrate processing apparatus 100. The substrate processing apparatus 100 shown in FIG. 1 processes a substrate W having a pattern including a plurality of structures.

[0017] The substrate W is, for example, a semiconductor wafer (e.g., a silicon wafer), a substrate for a liquid crystal display device, a substrate for a plasma display, a substrate for a field emission display (FED), a substrate for an optical disk, a substrate for a magnetic disk, a substrate for a magneto-optical disk, a substrate for a photomask, a ceramic substrate, or a substrate for a solar cell. Hereinafter, as an example, the substrate W is a silicon wafer.

[0018] As shown in FIG. 1, the substrate processing apparatus 100 includes a plurality of load ports LP, an indexer robot IR, a center robot CR, a plurality of processing units 1, a control device 2, a plurality of fluid boxes 3, and a chemical solution cabinet 4.

[0019] Each of the load ports LP accommodates a plurality of stacked substrates W. The indexer robot IR transports the substrate W between the load port LP and the center robot CR. The center robot CR transports the substrate W between the indexer robot IR and the processing unit 1. Each of the processing units 1 processes the substrate W with a chemical solution. Each of the fluid boxes 3 houses fluid equipment. The chemical solution cabinet 4 stores the chemical solution.

[0020] Specifically, a predetermined number of processing units 1 (three processing units 1 in the example of FIG. 1) are stacked in the vertical direction to form one tower TW. A plurality of towers TW are arranged so as to surround the center robot CR in plan view.

[0021] A plurality of fluid boxes 3 respectively correspond to a plurality of towers TW. The chemical solution in the chemical solution cabinet 4 is supplied to all the processing units 1 included in the tower TW corresponding to the fluid box 3 through one of the fluid boxes 3.

[0022] The control device 2 controls the load port LP, the indexer robot IR, the center robot CR, the processing unit 1, the fluid box 3, and the chemical solution cabinet 4. The control device 2 is, for example, a computer.

[0023] The control device 2 includes a control unit 21 and a storage unit 22. The control unit 21 includes a processor such as a CPU (Central Processing Unit). The storage unit 22 includes a storage device and stores data and computer programs. Specifically, the storage unit 22 includes a main storage device such as a semiconductor memory, and an auxiliary storage device such as a semiconductor memory, a solid state drive, and / or a hard disk drive. The storage unit 22 may include a removable medium. The storage unit 22 corresponds to an example of a non-transitory computer-readable storage medium.

[0024] Next, with reference to FIG. 2, the processing unit 1 will be described. FIG. 2 is a side view showing the inside of the processing unit 1.

[0025] As shown in FIG. 2, the processing unit 1 includes a chamber 11, a spin chuck 12, a spin motor 13, a chemical solution nozzle 14, a nozzle moving unit 15, a plurality of guards 16, a suspension nozzle 17, and a nozzle moving unit 18. Further, the substrate processing apparatus 100 further includes a valve 6, a pipe 7, a valve 8, and a pipe 9.

[0026] The spin chuck 12 corresponds to an example of the "substrate holding unit" of the present invention. The spin motor 13 corresponds to an example of the "substrate rotating unit" of the present invention. The chemical solution nozzle 14 corresponds to an example of the "chemical solution supply unit" of the present invention. The suspension nozzle 17 corresponds to an example of the "suspension supply unit" of the present invention.

[0027] The chamber 11 has a substantially box shape. The chamber 11 houses the spin chuck 12, the spin motor 13, the chemical solution nozzle 14, the nozzle moving unit 15, the plurality of guards 16, the suspension nozzle 17, the nozzle moving unit 18, a part of the pipe 7, and a part of the pipe 9.

[0028] The spin chuck 12 holds the substrate W. Specifically, the spin chuck 12 holds the substrate W substantially horizontally.

[0029] The spin motor 13 rotates the substrate W by rotating the spin chuck 12 holding the substrate W. Specifically, the spin motor 13 rotates the spin chuck 12 around the rotation axis AX. Therefore, the spin chuck 12 rotates the substrate W around the rotation axis AX while holding the substrate W horizontally. Specifically, the spin chuck 12 includes a spin base 121 and a plurality of chuck members 122. The spin base 121 is substantially disk-shaped and supports the plurality of chuck members 122 in a horizontal posture. The plurality of chuck members 122 hold the substrate W in a horizontal posture. Note that the spin chuck 12 may be, for example, a vacuum chuck or a Bernoulli chuck using the Bernoulli effect, and is not particularly limited.

[0030] The chemical liquid nozzle 14 supplies the chemical liquid to the upper surface of the substrate W. Specifically, the pipe 7 supplies the chemical liquid to the chemical liquid nozzle 14. The valve 6 is arranged in the pipe 7. And the valve 6 opens and closes the flow path of the pipe 7, and switches between the supply and the stop of the chemical liquid to the chemical liquid nozzle 14. When the valve 6 opens the flow path of the pipe 7, the chemical liquid nozzle 14 supplies the chemical liquid toward the substrate W.

[0031] The chemical liquid is, for example, diluted hydrofluoric acid (DHF), hydrofluoric acid (HF), fluonitric acid (a mixed liquid of hydrofluoric acid and nitric acid (HNO3)), buffered hydrofluoric acid (BHF), ammonium fluoride, HFEG (a mixed liquid of hydrofluoric acid and ethylene glycol), phosphoric acid (H3PO4), sulfuric acid, acetic acid, nitric acid, hydrochloric acid, aqueous ammonia, hydrogen peroxide water, organic acid (for example, citric acid, oxalic acid), organic alkali (for example, TMAH: tetramethylammonium hydroxide), sulfuric acid hydrogen peroxide water mixed liquid (SPM), ammonia hydrogen peroxide water mixed liquid (SC1), hydrochloric acid hydrogen peroxide water mixed liquid (SC2), surfactant, or corrosion inhibitor.

[0032] The nozzle moving unit 15 moves the chemical liquid nozzle 14 between the processing position and the retracted position. The processing position indicates a position above the substrate W. The retracted position indicates a position radially outside the substrate W with respect to the substrate W.

[0033] Specifically, the nozzle moving unit 15 includes an arm 151, a rotation shaft 152, and a nozzle moving mechanism 153. The arm 151 extends along a substantially horizontal direction. A chemical liquid nozzle 14 is attached to the tip of the arm 151. The arm 151 is coupled to the rotation shaft 152. The rotation shaft 152 extends along a substantially vertical direction. The nozzle moving mechanism 153 rotates the rotation shaft 152 around a rotation axis along the substantially vertical direction, and rotates the arm 151 along a substantially horizontal plane. As a result, the chemical liquid nozzle 14 moves along the substantially horizontal plane. For example, the nozzle moving mechanism 153 includes an arm swing motor (such as a servo motor) that rotates the rotation shaft 152 around the rotation axis. Further, the nozzle moving mechanism 153 moves the rotation shaft 152 up and down along the substantially vertical direction to move the arm 151 up and down. As a result, the chemical liquid nozzle 14 moves along the substantially vertical direction. For example, the nozzle moving mechanism 153 includes a ball screw mechanism and an arm lifting motor (such as a servo motor) that applies a driving force to the ball screw mechanism.

[0034] The suspension nozzle 17 supplies the suspension to the upper surface of the substrate W. Specifically, the pipe 9 supplies the suspension to the suspension nozzle 17. The valve 8 is disposed in the pipe 9. The valve 8 opens and closes the flow path of the pipe 9, and switches the supply and the supply stop of the suspension to the suspension nozzle 17. When the valve 8 opens the flow path of the pipe 9, the suspension nozzle 17 supplies the suspension toward the substrate W. For example, the pipe 9 is connected to a suspension tank that stores the suspension.

[0035] In this specification, the suspension refers to a substance in which pure water and a plurality of sublimable particles (a large number of sublimable particles) are mixed. Specifically, the suspension refers to a dispersion system in which a plurality of sublimable particles (a large number of sublimable particles) are dispersed in pure water. Pure water is the dispersion medium, and the sublimable particles are the dispersed phase. The sublimable particles are solid particles.

[0036] In this specification, pure water, which is the dispersion medium of the suspension, is construed in a broad sense and includes deionized water (DIW), carbonated water, electrolyzed ion water, hydrogen water, ozone water, or hydrochloric acid water with a dilution concentration (for example, about 10 ppm to 100 ppm). Further, the pure water may contain substances different from organic solvents (for example, gases, liquids, or solids). In this specification, the organic solvent is water-soluble and has a lower surface tension than pure water. For example, the organic solvent is a low-carbon monohydric alcohol, ethylene glycol, or a lower ketone. The low-carbon monohydric alcohol is, for example, methanol, ethanol, or IPA (isopropyl alcohol).

[0037] In this specification, the sublimable particles, which are the dispersed substances of the suspension, are, for example, cyclohexanone oxime, camphor, naphthalene, P-cresol, 1,4-benzoquinone, 2-chloronaphthalene, 4-nitrotoluene, diphenyl ether, or 2,6-dinitrotoluene. "Sublimable" indicates that a single substance, compound, or mixture has the property of phase-transitioning from a solid to a gas without passing through a liquid. "Sublimable particles" indicates particles having sublimability. Specifically, the "sublimable particles" have sublimability under the temperature and pressure within chamber 11. For example, the boiling point of the "sublimable particles" is higher than the boiling point of pure water.

[0038] The nozzle moving unit 18 moves the suspension nozzle 17 between the processing position and the retracted position. The processing position indicates a position above the substrate W. The retracted position indicates a position radially outside the substrate W with respect to the substrate W.

[0039] Specifically, the nozzle moving unit 18 includes an arm 181, a rotating shaft 182, and a nozzle moving mechanism 183. The nozzle moving mechanism 183 rotates the rotating shaft 152 around the rotation axis along the substantially vertical direction to rotate the arm 181 along the substantially horizontal plane. As a result, the suspension nozzle 17 moves along the substantially horizontal plane. Further, the nozzle moving mechanism 183 raises and lowers the rotating shaft 152 along the substantially vertical direction to raise and lower the arm 181. As a result, the suspension nozzle 17 moves along the substantially vertical direction. In addition, the configurations of the arm 181, the rotating shaft 182, and the nozzle moving mechanism 183 are the same as the configurations of the arm 151, the rotating shaft 152, and the nozzle moving mechanism 153, respectively.

[0040] Next, with reference to FIG. 3, a liquid film 26 of the suspension 25 formed on the upper surface of the substrate W will be described. FIG. 3(a) is a side view showing a state in which the liquid film 26 of the suspension 25 covers the upper surface of the substrate W. FIG. 3(b) is a side view showing an enlarged view of a part of the liquid film 26 of the suspension 25 and a part of the substrate W shown in FIG. 3(a).

[0041] As shown in FIG. 3(a), the suspension nozzle 17 forms the liquid film 26 of the suspension 25 on the upper surface of the substrate W by supplying the suspension 25 to the upper surface of the substrate W.

[0042] As shown in FIG. 3(b), the thickness t1 of the liquid film 26 is not particularly limited, but is, for example, 1 mm or more and 4 mm or less. The thickness t0 of the substrate W is not particularly limited, but is, for example, 0.5 mm or more and 1 mm or less.

[0043] Continuing to refer to FIG. 3(b), the principle in which pure water constituting the suspension 25 is removed from the substrate W and the sublimable particles constituting the suspension 25 remain on the substrate W will be described. When removing pure water from the suspension 25, the supply of the suspension 25 from the suspension nozzle 17 to the substrate W is stopped, and the rotation of the substrate W is continued.

[0044] Due to the centrifugal force caused by the rotation of the substrate W, the suspension 25 present in the region 261 of the liquid film 26 flows. Therefore, the suspension 25 in the region 261 is shaken off from the substrate W. As a result, the liquid level of the liquid film 26 drops. As the liquid level drops, the suspension 25 present in the region 262 of the liquid film 26 hardly flows despite the rotation of the substrate W. Therefore, in the region 262, the pure water in the suspension 25 mainly vaporizes, causing the liquid level of the liquid film 26 to drop. Thus, the sublimable particles in the suspension 25 are pushed down by the liquid level. Therefore, a large number of sublimable particles dispersed in the pure water accumulate on the upper surface of the substrate W. As the vaporization of the pure water further progresses, the pure water is removed from the substrate W, and a large number of deposited sublimable particles remain on the upper surface of the substrate W.

[0045] For example, the region 261 is a region on the order of millimeters. For example, the region 262 is a region on the order of micrometers. The region 262 is closer to the substrate W than the region 261.

[0046] Next, with reference to FIGS. 1, 2, 4, and 5, a substrate processing method according to Embodiment 1 of the present invention will be described. FIG. 4(a) is a diagram showing a state in which the chemical solution 27 covers the pattern PT of the substrate W in the chemical solution supply step. FIG. 4(b) is a diagram showing a state in which the suspension 25 covers the pattern PT of the substrate W in the suspension supply step. FIG. 4(c) is a diagram showing a state in which the pure water 251 decreases from the suspension 25 and the sublimable particles 252 are deposited between the structures 23 constituting the pattern PT in the pure water removal step. FIG. 5(a) is a diagram showing a state in which the pure water 251 is removed from the suspension 25 and the sublimable particles 252 are deposited between the structures 23 constituting the pattern PT of the substrate W after completion of the pure water removal step. FIG. 5(b) is a diagram showing a state during the sublimation of the sublimable particles 252 from between the structures 23 in the particle sublimation step. FIG. 5(c) is a diagram showing a state in which the sublimable particles 252 are removed from between the structures 23 after completion of the particle sublimation step.

[0047] As shown in FIG. 4(a), the substrate W has a pattern PT. That is, the pattern PT is formed on the upper surface of the substrate W. The pattern PT is, for example, a concavo-convex pattern. The pattern PT includes a plurality of structures 23. The structures 23 are, for example, fine structures. The aspect ratio AR of the structure 23 is, for example, 10 or more and 100 or less. The aspect ratio AR indicates the ratio of the length H to the length L (AR = H / L). The length L is, for example, 5 nm or more and 50 nm or less. The length H is, for example, 50 nm or more and 5000 nm or less. The length H indicates the length of the structure 23 in the first direction D1. The length L indicates the length of the structure 23 in the second direction D2.

[0048] The first direction D1 indicates a direction intersecting the substrate W. In the example of FIG. 4(a), the first direction D1 indicates a direction substantially orthogonal to the substrate W. The second direction D2 intersects the first direction D1. In the example of FIG. 4(a), the second direction D2 is substantially orthogonal to the first direction D1.

[0049] Among the plurality of structures 23, the interval G between adjacent structures 23 and 23 is, for example, 10 nm or more and 100 nm or less.

[0050] As an example, the structure 23 extends along the first direction D1. Note that FIG. 4(a) only schematically shows the structure 23, and the structure 23 can have any shape and configuration according to the purpose of use of the substrate W.

[0051] For example, the structure 23 is composed of a single layer or a plurality of layers. When the structure 23 is composed of a single layer, the structure 23 is an insulating layer, a semiconductor layer, or a conductor layer. When the structure 23 is composed of a plurality of layers, the structure 23 may include an insulating layer, a semiconductor layer, a conductor layer, or two or more of an insulating layer, a semiconductor layer, and a conductor layer.

[0052] The insulating layer is, for example, a silicon oxide film or a silicon nitride film. The semiconductor layer is, for example, a polysilicon film or an amorphous silicon film. The conductor layer is, for example, a metal film. The metal film is a film containing at least one of titanium, tungsten, copper, and aluminum, for example.

[0053] As shown in FIGS. 2 and 4(a), first, in the chemical solution supply step, the chemical solution nozzle 14 supplies the chemical solution 27 onto the upper surface of the substrate W. As a result, the substrate W is processed by the chemical solution 27.

[0054] Next, as shown in FIGS. 2 and 4(b), in the suspension supply step, the suspension nozzle 17 supplies the suspension 25 onto the upper surface of the substrate W. As a result, a liquid film 26 of the suspension 25 is formed on the upper surface of the substrate W. The suspension 25 is a substance in which pure water 251 and a plurality of sublimable particles 252 (a large number of sublimable particles 252) are mixed. In the suspension 25, the plurality of sublimable particles 252 are dispersed in the pure water 251. The sublimable particles 252 suppress the collapse of the structure 23 when the substrate W is dried. Details of this point will be described later.

[0055] The particle size (size) of the sublimable particles 252 is smaller than the interval G between adjacent structures 23 and 23. Therefore, according to Embodiment 1, the sublimable particles 252 can easily enter between the structures 23 and 23.

[0056] The particle size (size) of the sublimable particles 252 is, for example, not less than several nm and not more than several tens of nm. For example, the particle size of the sublimable particles 252 is 20 nm.

[0057] The density of the sublimable particles 252 in the suspension 25 is, for example, 0.1 or more and 0.9 or less in terms of volume fraction. The density of the sublimable particles 252 in the suspension 25 is, for example, a value that can occupy "M / 10" or more of the space SP between the structures 23 at the completion of the pure water removal step (Fig. 4(c)). M is a real number. M is, for example, "1", preferably "2", more preferably "3", more preferably "4", more preferably "5", more preferably "6", more preferably "7", more preferably "8", more preferably "9", and most preferably "10". This is because the more sublimable particles 252 occupy the space SP between the structures 23 at the completion of the pure water removal step (Fig. 4(c)), the more effectively the collapse of the structure 23 can be suppressed. Details of this point will be described later.

[0058] Next, as shown in Fig. 4(c), in the pure water removal step, the pure water 251 is removed (eliminated) from the upper surface of the substrate W so that the sublimable particles 252 remain between the adjacent structures 23. In this case, as the pure water 251 vaporizes in the region 262 shown in Fig. 3(b), the liquid surface 251a of the pure water 251 (suspension 25) descends. And the sublimable particles 252 remain between the adjacent structures 23. Therefore, according to Embodiment 1, when the pure water 251 is removed from the substrate W, the sublimable particles 252 support the structure 23. As a result, it is possible to suppress the collapse of the structure 23 due to the surface tension of the pure water 251.

[0059] Specifically, at least during the period when the pure water 251 between the structures 23 is vaporized (removed) (hereinafter referred to as "period T"), a plurality of sublimable particles 252 are deposited between the structures 23 over the entire region of the substrate W where the pattern PT is formed. In other words, at least during period T, a plurality of sublimable particles 252 are spread out between the structures 23. Put more simply, at least during period T, a plurality of sublimable particles 252 are filled between the structures 23. Therefore, the plurality of structures 23 are supported by the plurality of sublimable particles 252. As a result, when the pure water 251 is excluded from the substrate W, it is possible to suppress the structures 23 from collapsing due to the surface tension of the pure water 251.

[0060] In particular, in Embodiment 1, as shown in FIG. 4(b), the suspension 25 is supplied onto the upper surface of the substrate W. At this stage, the sublimable particles 252 have already entered between the structures 23. Then, as shown in FIG. 4(c), the pure water 251 is excluded from the suspension 25. In this case, as the liquid level 251a of the pure water 251 (suspension 25) drops, the sublimable particles 252 are pushed downward toward the pattern PT. As a result, the sublimable particles 252 for suppressing the collapse of the structures 23 constituting the pattern PT of the substrate W can be easily made to enter and deposit between the structures 23. That is, the pure water 251 allows the sublimable particles 252 to easily enter and deposit between the structures 23.

[0061] Specifically, in the pure water exclusion step, the spin motor 13 rotates the substrate W on which the liquid film 26 of the suspension 25 is formed by rotating the spin base 121. That is, in the pure water exclusion step, the pure water 251 is excluded from the substrate W by rotating the substrate W with the supply of the suspension 25 stopped. Therefore, according to Embodiment 1, the pure water 251 can be easily excluded from the substrate W with a simple configuration.

[0062] Also, as an example, the execution time of the pure water removal process is longer than the execution time of a predetermined process (hereinafter referred to as "predetermined process ST"). The predetermined process ST indicates a process of spinning pure water without the sublimable particles 252 away from the substrate by rotation. The reason why the execution time of the pure water removal process is longer than the execution time of the predetermined process ST is that the sublimable particles 252 are mixed in the pure water 251, so it takes time to remove the pure water 251 compared to pure water without the sublimable particles. If the execution time of the pure water removal process is longer than the execution time of the predetermined process ST, the pure water can be more reliably removed from the substrate W. The "predetermined process ST" is, for example, a rinse process (rinse liquid supply process), and the pure water is used as the rinse liquid. The "rinse process (rinse liquid supply process)" indicates a process of flushing away chemical solutions, by-products after treatment with chemical solutions, and / or foreign substances from the substrate W.

[0063] Specifically, in the pure water removal process, the control unit 21 shown in FIG. 2 executes pure water removal control. The pure water removal control indicates control for removing the pure water 251 from the upper surface of the substrate W while leaving the sublimable particles 252 between the adjacent structures 23. In this case, the control unit 21 controls the spin motor 13 to rotate the spin chuck 12. As a result, the substrate W rotates. In this example, the pure water removal control indicates control for rotating the substrate W by the spin motor 13. And, as an example, the execution time of the pure water removal control is longer than the execution time of the predetermined process ST.

[0064] Here, in the pure water removal process, the sublimable particles 252 are left in the space SP so that the sublimable particles 252 occupy "M / 10" or more of the space SP between the structures 23. M is a real number. M is, for example, "1", preferably "2", more preferably "3", more preferably "4", more preferably "5", more preferably "6", more preferably "7", more preferably "8", more preferably "9", and most preferably "10".

[0065] Next, as shown in FIG. 5(a), when the pure water removal process is completed, the pure water 251 is removed, and sublimable particles 252 remain between the adjacent structures 23. In the example of FIG. 5(a), a plurality of sublimable particles 252 are deposited between the structures 23. In other words, a plurality of sublimable particles 252 are spread out between the structures 23. Further in other words, a plurality of sublimable particles 252 are filled between the structures 23.

[0066] Next, as shown in FIGS. 1 and 5(b), in the particle sublimation process, the sublimable particles 252 remaining between the structures 23 are sublimated. That is, the sublimable particles 252 deposited between the structures 23 are sublimated. As a result, in Embodiment 1, the sublimable particles 252 can be removed from the substrate W while maintaining the dry state of the substrate W.

[0067] Next, as shown in FIG. 5(c), when the particle sublimation process is completed, the sublimable particles 252 are removed from between the adjacent structures 23.

[0068] As described above with reference to FIGS. 4 and 5, according to the substrate processing apparatus 100 and the substrate processing method according to Embodiment 1, the suspension 25 in which the pure water 251 and the plurality of sublimable particles 252 are mixed is supplied to the upper surface of the substrate W. Then, the pure water 251 is removed from the upper surface of the substrate W so that the sublimable particles 252 remain (deposit) between the adjacent structures 23. Therefore, when the pure water 251 is removed from the substrate W, the sublimable particles 252 support the structure 23. As a result, it is possible to suppress the collapse of the structure 23 due to the surface tension of the pure water 251. Then, the sublimable particles 252 remaining (deposited) between the structures 23 are sublimated to complete the drying of the substrate W. In this way, when drying the substrate W, it is possible to suppress the collapse of the structure 23 constituting the pattern PT of the substrate W without using an organic solvent such as IPA.

[0069] In particular, in Embodiment 1, since an organic solvent such as IPA is not used when drying the substrate W, metal contamination of the substrate W due to trace metals can be prevented. For example, within the upper surface of the substrate W, a metal contamination level of less than 1E8 (atoms / cm 2 ) can be easily achieved. Therefore, the quality and reliability of the device obtained from the substrate W can be improved. For example, when manufacturing an image sensor from the substrate W, even in the drying of the deep trenches around the color filter portion of the image sensor, the occurrence of pixel defects called white scratches caused by trace metals can be prevented.

[0070] Also, since an organic solvent such as IPA is not used when drying the substrate W, the load on the global environment can be reduced.

[0071] Here, referring to FIGS. 1, 2, 6, and 7, another example of the pattern PT of the substrate W will be described. FIG. 6(a) is a diagram showing a state in which the chemical liquid 27 covers the pattern PT of the substrate W in the chemical liquid supply step. FIG. 6(b) is a diagram showing a state in which the suspension 25 covers the pattern PT of the substrate W in the suspension supply step. FIG. 6(c) is a diagram showing a state in which pure water 251 decreases from the suspension 25 and sublimable particles 252 are deposited between the structures 23 constituting the pattern PT in the pure water exclusion step. FIG. 7(a) is a diagram showing a state in which pure water 251 is removed from the suspension 25 and sublimable particles 252 are deposited between the structures 23 constituting the pattern PT of the substrate W after completion of the pure water exclusion step. FIG. 7(b) is a diagram showing a state during sublimation of the sublimable particles 252 from between the structures 23 in the particle sublimation step. FIG. 7(c) is a diagram showing a state in which the sublimable particles 252 are removed from between the structures 23 after completion of the particle sublimation step. Hereinafter, the points different from the content described with reference to FIGS. 4 and 5 will be mainly described.

[0072] As shown in FIG. 6(a), the substrate W has a pattern PT. In the pattern PT, each of the plurality of structures 23 has a structure 241 and a plurality of convex portions 242.

[0073] The structure 241 extends along the first direction D1 as an example. The convex portion 242 protrudes from the structure 241 along the second direction D2. The plurality of convex portions 242 are formed at intervals in the first direction D1. Therefore, a space SPX exists between the convex portions 242 facing each other in the second direction D2. Note that Fig. 6(a) only schematically shows the structure 23, and the structure 23 can have any shape and configuration according to the use purpose of the substrate W.

[0074] As shown in Figs. 2 and 6(a), first, in the chemical solution supply step, the chemical solution nozzle 14 supplies the chemical solution 27 to the upper surface of the substrate W. As a result, the substrate W is processed by the chemical solution 27.

[0075] Next, as shown in Figs. 2 and 6(b), in the suspension supply step, the suspension nozzle 17 supplies the suspension 25 to the upper surface of the substrate W. As a result, a liquid film 26 of the suspension 25 is formed on the upper surface of the substrate W.

[0076] The particle size of the sublimable particles 252 is smaller than the interval G between adjacent structures 23. Therefore, in the suspension supply step, the sublimable particles 252 enter between the structures 23. The interval G indicates, for example, the interval between the closest portions of adjacent structures 23 in the first direction D1.

[0077] Next, as shown in Fig. 6(c), in the pure water removal step, the pure water 251 is removed from the upper surface of the substrate W so that the sublimable particles 252 remain between adjacent structures 23. For example, in the pure water removal step, the pure water 251 is removed from the substrate W by rotating the substrate W with the supply of the suspension 25 stopped.

[0078] In the pure water removal process, as the pure water 251 vaporizes in the region 262 shown in FIG. 3(b), the liquid surface 251a of the pure water 251 (suspension 25) descends. Then, sublimable particles 252 remain between the structures 23 adjacent to each other in the first direction D1. Also, sublimable particles 252 remain between the convex portions 242 adjacent to each other in the second direction D2. Therefore, according to Embodiment 1, when removing the pure water 251 from the substrate W, the sublimable particles 252 support not only the structure 241 but also the convex portions 242. As a result, it is possible to suppress the collapse of the structure 241 and the convex portions 242 due to the surface tension of the pure water 251.

[0079] Specifically, at least during the period T in which the pure water 251 between the structures 23 vaporizes (is removed), over the entire region of the substrate W where the pattern PT is formed, a plurality of sublimable particles 252 are deposited between the structures 23 adjacent to each other in the first direction D1, and a plurality of sublimable particles 252 are filled between the convex portions 242 adjacent to each other in the second direction D2. In other words, at least during the period T, a plurality of sublimable particles 252 are spread between the structures 23 and between the convex portions 242. Therefore, the structure 241 of the structure 23 and the convex portions 242 are supported by the plurality of sublimable particles 252. As a result, when removing the pure water 251 from the substrate W, it is possible to suppress the collapse of the structure 241 and the convex portions 242 due to the surface tension of the pure water 251.

[0080] In particular, in Embodiment 1, as shown in FIG. 6(b), the suspension 25 is supplied to the upper surface of the substrate W. At this stage, the sublimable particles 252 have already entered between the structures 23 adjacent to each other in the first direction D1 and between the convex portions 242 adjacent to each other in the second direction D2. Then, as shown in FIG. 6(c), pure water 251 is removed from the suspension 25. In this case, due to the lowering of the liquid level 251a of the pure water 251 (suspension 25), the sublimable particles 252 are pushed downward toward the pattern PT. As a result, the sublimable particles 252 can easily enter and deposit between the structures 23 and between the convex portions 242 and can be easily filled between the convex portions 242 and the convex portions 242.

[0081] Next, as shown in FIG. 7(a), when the pure water removal process is completed, the pure water 251 is removed, and the sublimable particles 252 remain between the structures 23 adjacent to each other in the first direction D1 and between the convex portions 242 adjacent to each other in the second direction D2. In the example of FIG. 7(a), a plurality of sublimable particles 252 are deposited between the structures 23, and a plurality of sublimable particles 252 are filled between the convex portions 242 and the convex portions 242. In other words, a plurality of sublimable particles 252 are spread between the structures 23 and between the convex portions 242 and the convex portions 242.

[0082] Next, as shown in FIGS. 1 and 7(b), in the particle sublimation process, the sublimable particles 252 remaining between the structures 23 and between the convex portions 242 that constitute the pattern PT are sublimated. As a result, in Embodiment 1, the sublimable particles 252 can be removed from the substrate W while maintaining the dry state of the substrate W.

[0083] Next, as shown in FIG. 7(c), when the particle sublimation process is completed, the sublimable particles 252 are removed from between the structures 23 and between the convex portions 242 and the convex portions 242.

[0084] As described above with reference to FIGS. 4 to 7, by the suspension supply step, the pure water removal step, and the particle sublimation step, without using an organic solvent, while suppressing the collapse of the structure 23 constituting the pattern PT of the substrate W, the substrate W after being treated with the chemical solution 27 can be dried.

[0085] Next, with reference to FIGS. 1, 2, and 8, a substrate processing method according to Embodiment 1 will be described. The substrate processing apparatus 100 executes the substrate processing method. In the substrate processing method, a substrate W having a pattern PT including a plurality of structures 23 is processed. FIG. 8 is a flowchart showing the substrate processing method. As shown in FIG. 8, the substrate processing method includes steps S1 to S6. Steps S1 to S6 are executed according to the control by the control unit 21.

[0086] As shown in FIGS. 1, 2, and 8, in step S1, the center robot CR carries the substrate W into the processing unit 1. Then, in the processing unit 1, the spin chuck 12 holds the substrate W, and further, the spin motor 13 rotates the substrate W by rotating the spin chuck 12.

[0087] Next, in step S2, the chemical solution nozzle 14 supplies the chemical solution 27 to the upper surface of the rotating substrate W. When the chemical solution nozzle 14 executes the supply of the chemical solution 27 during a predetermined chemical solution supply period, it stops the supply of the chemical solution 27. Step S2 corresponds to an example of the "chemical solution supply step" of the present invention.

[0088] Next, in step S3, the suspension nozzle 17 forms a liquid film 26 of the suspension 25 on the upper surface of the substrate W by supplying the suspension 25 to the upper surface of the rotating substrate W. When the suspension nozzle 17 executes the supply of the suspension 25 during a predetermined suspension supply period, it stops the supply of the suspension 25. Step S3 corresponds to an example of the "suspension supply step" of the present invention.

[0089] In particular, since the suspension 25 contains pure water 251, step S3 also functions as a rinsing step. This is because the chemical solution 27 is washed away by the pure water 251. Therefore, in this case, the rinsing step can be omitted, and the man-hours for processing the substrate W can be reduced.

[0090] Next, in step S4, the pure water 251 is removed from the upper surface of the substrate W so that the sublimable particles 252 remain between the structures 23 adjacent to each other on the substrate W. That is, in step S4, the control unit 21 executes pure water removal control. Step S4 is executed, for example, during a predetermined pure water removal period. Step S4 corresponds to an example of the "pure water removal step" of the present invention.

[0091] Specifically, also in step S4, the spin motor 13 continuously rotates the spin chuck 12 and the substrate W from step S3. That is, the spin motor 13 removes the pure water 251 from the substrate W by rotating the substrate W on which the liquid film 26 is formed. In this case, in the range of the region 261 in FIG. 3(b), the suspension 25 is removed from the substrate W by the flow of the suspension 25 due to centrifugal force. And in the range of the region 262 in FIG. 3(b), the pure water 251 constituting the suspension 25 vaporizes, so that the pure water 251 is removed from the substrate W. In this case, at least during the period T in which the pure water 251 vaporizes from between the structures 23, the sublimable particles 252 remain between the structures 23. That is, the sublimable particles 252 are deposited between the structures 23. As a result, according to Embodiment 1, since the structure 23 is supported by the sublimable particles 252, it is possible to suppress the collapse of the structure 23 due to the surface tension of the pure water 251. Further, in Embodiment 1, the pure water 251 can easily cause the sublimable particles 252 to enter between the structures 23.

[0092] The rotation speed of the substrate W in step S4 is, for example, higher than the rotation speed of the substrate W in steps S2 and S3. The rotation speed indicates, for example, the number of rotations of the substrate W per unit time. The rotation speed of the substrate W in step S4 is determined, for example, experimentally and / or empirically.

[0093] Next, in step S5, the sublimable particles 252 remaining between the structures 23 of the substrate W are sublimated. Specifically, also in step S5, the spin motor 13 continuously rotates the spin chuck 12 and the substrate W from step S4. That is, the spin motor 13 promotes the sublimation of the sublimable particles 252 by rotating the substrate W. Note that the sublimable particles 252 may be sublimated naturally in a state where the substrate W is stopped.

[0094] The rotation speed of the substrate W in step S5 is, for example, the same as the rotation speed of the substrate W in step S4. However, the rotation speed of the substrate W in step S5 may be greater than or less than the rotation speed of the substrate W in step S4. The rotation speed of the substrate W in step S5 is determined, for example, experimentally and / or empirically.

[0095] When the spin motor 13 executes step S5 for a first predetermined period, the spin motor 13 stops the rotation of the spin chuck 12 to stop the rotation of the substrate W. Note that when the spin motor 13 executes from step S4 to step S5 for a second predetermined period, the spin motor 13 may stop the rotation of the spin chuck 12 to stop the rotation of the substrate W. The first predetermined period and the second predetermined period are determined, for example, experimentally and / or empirically.

[0096] Next, in step S6, the center robot CR unloads the substrate W from the processing unit 1. Then, the substrate processing method ends.

[0097] As described above with reference to FIG. 8, according to the substrate processing method according to Embodiment 1, by executing step S3, step S4, and step S5, when drying the substrate W after being processed by the chemical solution 27, it is possible to suppress the collapse of the structure 23 constituting the pattern PT of the substrate W without using an organic solvent such as IPA.

[0098] (Modification example) A modification of Embodiment 1 of the present invention will be described. The modification is mainly different from Embodiment 1 described with reference to FIGS. 1 to 8 in that the suspension contains a pH adjuster. Hereinafter, the differences between the modification and Embodiment 1 will be mainly described.

[0099] In the modification, the suspension supplied to the substrate W by the suspension nozzle 17 contains a pH adjuster. The pH adjuster adjusts the hydrogen ion index (pH) of the suspension.

[0100] In the first example of the modification, the suspension exhibits alkalinity due to the pH adjuster. Preferably, the hydrogen ion index of the suspension is 9 or more. According to this preferred example, since the negatively charged particles repel each other, aggregation of the sublimable particles in the suspension can be suppressed. Therefore, the sublimable particles can smoothly enter between the structures 23 of the substrate W. As a result, when drying the substrate W, the collapse of the structure 23 can be more effectively suppressed. In the first example, the pH adjuster is a base. The base is, for example, ammonia.

[0101] In the second example of the modification, the suspension exhibits acidity due to the pH adjuster. Preferably, the hydrogen ion index of the suspension is 4 or less. According to this preferred example, since the positively charged particles repel each other, aggregation of the sublimable particles in the suspension can be suppressed. Therefore, the sublimable particles can smoothly enter between the structures 23 of the substrate W. As a result, when drying the substrate W, the collapse of the structure 23 can be more effectively suppressed. In the second example, the pH adjuster is an acid. The acid is, for example, hydrochloric acid.

[0102] (Embodiment 2) With reference to FIGS. 9 and 10, a substrate processing apparatus 100 according to Embodiment 2 of the present invention will be described. Embodiment 2 is mainly different from Embodiment 1 in that the substrate processing apparatus 100 according to Embodiment 2 performs a rinse liquid supply step before the suspension supply step. In addition, the overall configuration of the substrate processing apparatus 100 according to Embodiment 2 is the same as the overall configuration of the substrate processing apparatus 100 according to Embodiment 1 described with reference to FIG. 1. Hereinafter, the differences between Embodiment 2 and Embodiment 1 will be mainly described.

[0103] FIG. 9 is a side view showing the interior of the processing unit 1 according to Embodiment 2. As shown in FIG. 9, in addition to the configuration of the processing unit 1 according to Embodiment 1 shown in FIG. 2, the processing unit 1 according to Embodiment 2 includes a rinse liquid nozzle 31, an inert gas supply unit 41, and a unit operation unit 42. Further, in addition to the configuration of the substrate processing apparatus 100 according to Embodiment 1 shown in FIG. 1, the substrate processing apparatus 100 according to Embodiment 2 includes a pipe 43 and a valve 44. The chamber 11 houses the rinse liquid nozzle 31, the inert gas supply unit 41, the unit operation unit 42, a part of the pipe 32, and a part of the pipe 43.

[0104] The rinse liquid nozzle 31 supplies the rinse liquid to the upper surface of the substrate W. Specifically, the pipe 32 supplies the rinse liquid to the rinse liquid nozzle 31. The valve 33 is disposed in the pipe 32. The valve 33 opens and closes the flow path of the pipe 32, and switches between the supply and the stop of the rinse liquid to the rinse liquid nozzle 31. When the valve 33 opens the flow path of the pipe 32, the rinse liquid nozzle 31 supplies the rinse liquid toward the substrate W. The rinse liquid is pure water. The rinse liquid nozzle 31 corresponds to an example of the "rinse liquid supply unit" of the present invention.

[0105] Note that, for example, a nozzle moving unit (not shown) having the same configuration as the nozzle moving unit 15 can move the rinse liquid nozzle 31 up and down or horizontally rotate the rinse liquid nozzle 31.

[0106] The inert gas supply unit 41 supplies an inert gas to the substrate W. Specifically, the inert gas supply unit 41 is located above the spin chuck 12. The inert gas supply unit 41 includes a shielding plate 411, a support shaft 413, and a gas nozzle 415.

[0107] The shutter plate 411 is, for example, substantially disc-shaped. The shutter plate 411 is arranged such that the lower surface of the shutter plate 411 is substantially horizontal. Further, the shutter plate 411 is arranged such that the central axis of the shutter plate 411 is located on the rotation axis AX. The lower surface of the shutter plate 411 faces the substrate W held by the spin chuck 12. The shutter plate 411 is connected to the lower end of the support shaft 413 in a horizontal posture.

[0108] The unit operation part 42 raises or lowers the inert gas supply unit 41 between the proximity position and the retracted position. The proximity position indicates a position where the shutter plate 411 descends and approaches the upper surface of the substrate W with a predetermined interval. At the proximity position, the shutter plate 411 covers the surface of the substrate W and blocks the upper part above the surface of the substrate W. That is, at the proximity position, the shutter plate 411 faces the surface of the substrate W and covers the upper part above the surface of the substrate W. The retracted position is above the proximity position and indicates a position where the shutter plate 411 ascends and is separated from the substrate W. In FIG. 9, the shutter plate 411 is located at the retracted position. Further, the unit operation part 42 rotates the inert gas supply unit 41 at the proximity position. For example, the unit operation part 42 includes a ball screw mechanism and a lifting motor (for example, a servo motor) that applies a driving force to the ball screw mechanism. For example, the unit operation part 42 includes a motor and a transmission mechanism that transmits the rotation of the motor to the inert gas supply unit 41.

[0109] The gas nozzle 415 of the inert gas supply unit 41 is arranged inside the shutter plate 411 and the support shaft 413. The tip of the gas nozzle 415 is exposed from the lower surface of the shutter plate 411.

[0110] The gas nozzle 415 supplies an inert gas to the upper surface of the substrate W. Specifically, the pipe 43 supplies the inert gas to the gas nozzle 415. The valve 44 is disposed in the pipe 43. Then, the valve 44 opens and closes the flow path of the pipe 43, and switches the supply and the stop of the inert gas to the gas nozzle 415. When the inert gas supply unit 41 is located at the proximity position, when the valve 44 opens the flow path of the pipe 43, the gas nozzle 415 supplies the inert gas toward the upper surface of the substrate W. The inert gas is, for example, nitrogen or argon. The gas nozzle 415 corresponds to an example of the "inert gas supply unit" of the present invention.

[0111] Note that the inert gas supply unit 41 only needs to have at least the gas nozzle 415, and does not need to have the shielding plate 411 and the support shaft 413.

[0112] Next, referring to FIGS. 1, 9, and 10, a substrate processing method according to Embodiment 2 will be described. FIG. 10 is a flowchart showing the substrate processing method. As shown in FIG. 10, the substrate processing method includes steps S11 to S18. Steps S11 to S18 are executed according to the control by the control unit 21.

[0113] As shown in FIGS. 1, 9, and 10, in step S11, the center robot CR carries the substrate W into the processing unit 1. In addition, step S11 is the same as step S1 in FIG. 8.

[0114] Next, in step S12, the chemical liquid nozzle 14 supplies the chemical liquid 27 to the upper surface of the rotating substrate W. That is, before steps S13 and S14, the chemical liquid nozzle 14 supplies the chemical liquid 27 to the upper surface of the rotating substrate W. In addition, step S12 is the same as step S2 in FIG. 8. Step S12 corresponds to an example of the "chemical liquid supply step" of the present invention.

[0115] Next, in step S13, the rinse liquid nozzle 31 supplies the rinse liquid to the upper surface of the rotating substrate W, thereby flushing out the chemical liquid 27 from the substrate W. That is, after step S12, the rinse liquid nozzle 31 supplies the rinse liquid to the upper surface of the rotating substrate W, thereby flushing out the chemical liquid 27 from the substrate W. When the rinse liquid nozzle 31 executes the supply of the rinse liquid during a predetermined rinse liquid supply period, it stops the supply of the rinse liquid. Step S13 corresponds to an example of the "rinse liquid supply step" of the present invention.

[0116] Next, in step S14, the suspension nozzle 17 supplies the suspension 25 to the upper surface of the rotating substrate W. Specifically, the suspension nozzle 17 forms a liquid film 26 of the suspension 25 on the upper surface of the substrate W by supplying the suspension 25 to the upper surface of the rotating substrate W. That is, step S14 is executed after step S13. In addition, step S14 is the same as step S3 in FIG. 8. Step S14 corresponds to an example of the "suspension supply step" of the present invention.

[0117] In particular, since the suspension 25 contains pure water 251, in combination with step S13, the chemical liquid 27 can be discharged from the substrate W more effectively.

[0118] Note that also in Embodiment 2, the suspension 25 may contain the pH adjuster according to the modification example of Embodiment 1.

[0119] Next, in step S15, the pure water 251 is excluded from the upper surface of the substrate W so that the sublimable particles 252 remain between the structures 23 adjacent to each other on the substrate W. That is, in step S15, the control unit 21 executes pure water exclusion control. In addition, step S15 is the same as step S4 in FIG. 8. Step S15 corresponds to an example of the "pure water exclusion step" of the present invention.

[0120] Next, step S17 is executed in parallel with step S16.

[0121] That is, in step S16, the sublimable particles 252 remaining between the structures 23 of the substrate W are sublimated. In addition, step S16 is the same as step S5 in FIG. 8. Step S16 corresponds to an example of the "particle sublimation step" of the present invention.

[0122] On the other hand, in step S17, the gas nozzle 415 supplies an inert gas to the upper surface of the rotating substrate W. As a result, according to Embodiment 2, the sublimation of the sublimable particles 252 can be further promoted. When the gas nozzle 415 executes the supply of the inert gas during a predetermined inert gas supply period (for example, the first predetermined period), the supply of the inert gas is stopped. Step S17 corresponds to an example of the "inert gas supply step" of the present invention.

[0123] Note that step S17 may be started in parallel with step S15. That is, the gas nozzle 415 may supply an inert gas to the upper surface of the substrate W during the execution periods of steps S15 and S16. In this case, the elimination of the pure water 251 and the sublimation of the sublimable particles 252 can be further promoted.

[0124] Next, in step S18, the center robot CR carries the substrate W out of the processing unit 1. Then, the substrate processing method ends.

[0125] As described above with reference to FIG. 10, according to the substrate processing method according to Embodiment 2, by executing steps S12 to S16, when drying the substrate W after processing with the chemical solution 27, without using an organic solvent such as IPA, the collapse of the structure 23 constituting the pattern PT of the substrate W can be suppressed. Note that the substrate processing method may not include step S13 or step S17.

[0126] Next, the present invention will be specifically described based on examples, but the present invention is not limited by the following examples.

Examples

[0127] Referring to FIG. 11, Examples 1 to 3 of the present invention and comparative examples will be described. In Examples 1 to 3 and the comparative example, a 1 cm × 1 cm square coupon sample was used. The coupon sample was silicon. A large number of pillars were formed on the upper surface of the coupon sample. The aspect ratio AR (= H / L, FIG. 4(a)) of the pillars was 19 to 20. Also, the height H of the pillars was about 530 nm, and the width L of the pillars was about 27 nm. The distance G between the pillars was about 56 nm.

[0128] In Examples 1 to 3, a liquid film of the suspension was formed on the upper surface of the coupon sample. The thickness t1 of the liquid film was about 1 mm to 2 mm. The suspension was a dispersion system in which cyclohexanone oxime was dispersed in DIW. That is, cyclohexanone oxime was used as the sublimable particles that are the dispersed phase. Also, DIW was used as the pure water that is the dispersion medium. The density of cyclohexanone oxime in the suspension was 0.10% to 3.12% by volume fraction. The suspension did not contain an organic solvent such as IPA.

[0129] Then, in Examples 1 to 3, the coupon sample was dried by leaving the coupon sample on which the liquid film of the suspension was formed. That is, the DIW contained in the suspension was naturally dried, and the cyclohexanone oxime contained in the suspension was naturally sublimated. Then, the dried coupon sample was observed by SEM (scanning electron microscope).

[0130] On the other hand, in the comparative example, a liquid film of DIW was formed on the upper surface of the coupon sample. The DIW did not contain cyclohexanone oxime. Also, the DIW did not contain an organic solvent such as IPA. Then, the coupon sample was dried by leaving the coupon sample on which the liquid film of DIW was formed. That is, the DIW was naturally dried. The dried coupon sample was observed by SEM.

[0131] Fig. 11(a) is a photograph showing the state of the coupon sample according to the comparative example after drying. Figs. 11(b) to 11(d) are photographs showing the states of the coupon samples according to Examples 1 to 3 of the present invention after drying. In Figs. 11(a) to 11(d), white spots indicate the state where the pillars have collapsed, and black (dark gray) regions indicate the state where the pillars have not collapsed.

[0132] As shown in Fig. 11(a), in the comparative example, white spots were present throughout the coupon sample. That is, in the comparative example, the pillars had collapsed throughout the coupon sample.

[0133] On the other hand, as shown in Figs. 11(b) to 11(d), in Examples 1 to 3, black (dark gray) regions were observed partially in the coupon samples. That is, in Examples 1 to 3, although partially, the pillars had not collapsed in the coupon samples. Therefore, it was confirmed that the collapse of the pillars can be suppressed by using a suspension (DIW in which cyclohexanone oxime is dispersed) when drying the coupon sample. That is, it was presumed that the collapse of the structure 23 of the substrate W can be suppressed by using a suspension without using an organic solvent such as IPA when drying the substrate W.

[0134] The embodiments of the present invention have been described above with reference to the drawings. However, the present invention is not limited to the above embodiments, and can be implemented in various forms without departing from the gist thereof. Also, the plurality of components disclosed in the above embodiments can be modified as appropriate. For example, a component among all the components shown in a certain embodiment may be added to the components of another embodiment, or some of the components among all the components shown in a certain embodiment may be deleted from the embodiment.

[0135] In addition, for the purpose of facilitating the understanding of the invention, the drawings schematically show each component mainly. The thickness, length, number, interval, etc. of each illustrated component may be different from the actual ones for the convenience of drawing preparation. Also, the configuration of each component shown in the above embodiments is an example and is not particularly limited. Needless to say, various changes can be made without substantially departing from the effects of the present invention.

Industrial Applicability

[0136] The present invention relates to a substrate processing method and a substrate processing apparatus and has industrial applicability.

Explanation of Reference Numerals

[0137] 12 Spin chuck (substrate holding part) 13 Spin motor (substrate rotating part) 17 Suspension nozzle (suspension supply part) 100 Substrate processing apparatus W Substrate

Claims

1. A substrate processing method for processing a substrate having a pattern including a plurality of structures, comprising: a suspension supply step of forming a liquid film of the suspension on the upper surface of the substrate by supplying a suspension in which pure water and a plurality of sublimable particles are mixed to the upper surface of the substrate; a pure water removal step of removing the pure water from the upper surface of the substrate so that the sublimable particles remain between the adjacent structures; a particle sublimation step of sublimating the sublimable particles remaining between the structures; The substrate processing method comprising the above steps.

2. The substrate processing method according to claim 1, wherein the hydrogen ion exponent of the suspension is 4 or less or 9 or more.

3. The substrate processing method according to claim 1 or 2, further comprising an inert gas supply step of supplying an inert gas to the upper surface of the substrate in parallel with the particle sublimation step.

4. a chemical solution supply step of supplying a chemical solution to the upper surface of the substrate before the suspension supply step; a rinse solution supply step of washing away the chemical solution by supplying a rinse solution to the upper surface of the substrate after the chemical solution supply step; The method further comprising: The suspension supply step is performed after the rinse solution supply step. In the pure water removal step, the pure water is removed from the substrate by rotating the substrate. The substrate processing method according to any one of claims 1 to 3.

5. The sublimable particles are cyclohexanone oxime, camphor, naphthalene, P-cresol, 1,4-benzoquinone, 2-chloronaphthalene, 4-nitrotoluene, diphenyl ether, or 2,6-dinitrotoluene. The substrate processing method according to any one of claims 1 to 4.

6. A substrate processing apparatus for processing a substrate having a pattern including a plurality of structures, comprising: a substrate holding unit for holding the substrate; a suspension supply unit for forming a liquid film of the suspension on the upper surface of the substrate by supplying a suspension in which pure water and a plurality of sublimable particles are mixed to the upper surface of the substrate; a substrate rotation unit for rotating the substrate on which the liquid film is formed by rotating the substrate holding unit. The substrate processing apparatus comprising the above components.

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