JP7633058B2 - Substrate processing method and substrate processing apparatus - Google Patents

Description

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

In the substrate processing apparatus described in Patent Document 1, a first processing liquid is supplied to the pattern surface of the substrate to perform a first wet processing. Next, sublimable solid particles with a temperature higher than the freezing point of the first processing liquid are sprayed onto the pattern surface that has been subjected to the first wet processing. As a result, the first processing liquid adhering to the pattern surface is removed, and the pattern surface is covered with sublimable solid particles. Next, the sublimable solid particles covering the pattern surface are sublimated from the solid phase to the gas phase and removed from the pattern surface. As a result, the substrate can be dried without collapsing the uneven pattern formed on the pattern surface of the substrate.

JP 2017-152600 A

However, in the substrate processing apparatus described in Patent Document 1, depending on the spacing between the structures that make up the uneven pattern, it may be difficult for the sublimable solid particles to penetrate between the structures. In particular, as uneven patterns have become finer in recent years, there is a possibility that the number of cases in which it is difficult for the sublimable solid particles to penetrate between the structures may increase. For example, research and development of high aspect ratio structures such as STI (shallow trench isolation) and Capacitors is progressing.

The present invention has been made in consideration of the above problems, and its purpose is to provide a substrate processing method and substrate processing apparatus that can easily allow particles to enter between structures to prevent the collapse of structures that make up a substrate pattern.

According to one aspect of the present invention, a substrate processing method processes a substrate having a pattern including a plurality of structures. The substrate processing method includes a suspension supplying step and a processing liquid removing step. In the suspension supplying step, a suspension containing a mixture of a processing liquid and a plurality of particles that are not dissolved in the processing liquid is supplied to an upper surface of the substrate, thereby forming a liquid film of the suspension on the upper surface of the substrate. In the processing liquid removing step, the processing liquid is removed from the upper surface of the substrate such that the particles remain (preferably accumulate) between adjacent structures.
In one aspect of the present invention, the processing liquid removal step preferably removes the processing liquid from the upper surface of the substrate such that the particles remain between adjacent structures and support the structures.

In one aspect of the present invention, the substrate processing method preferably further includes a particle removing step of removing the particles remaining (preferably deposited) between the structures by using a non-liquid.

In one aspect of the present invention, it is preferable that the particles are inorganic and the non-liquid is a vapor of a chemical liquid. In the particle removal step, it is preferable that the vapor of the chemical liquid is supplied to the upper surface of the substrate to remove the particles from between the structures.

In one aspect of the present invention, the particles are preferably silica.

In one aspect of the present invention, it is preferable that the particles are organic and the non-liquid is ultraviolet light or ozone. In the particle removal step, it is preferable that the particles are removed from between the structures by supplying the ozone to the upper surface of the substrate or by irradiating the upper surface of the substrate with ultraviolet light.

In one aspect of the present invention, the particles are preferably polystyrene.

In one aspect of the present invention, the treatment liquid is preferably a rinse liquid.

In one aspect of the present invention, the size of the particles is preferably smaller than the distance between adjacent structures.

In one aspect of the present invention, in the treatment liquid removal step, it is preferable to remove the treatment liquid from the substrate by rotating the substrate.

In one aspect of the present invention, it is preferable that the execution time of the process liquid removal process is longer than the execution time of the predetermined process. It is preferable that the predetermined process is a process of shaking off the same process liquid as the process liquid, which does not contain the particles, from the substrate by rotation.

In one aspect of the present invention, it is preferable that the substrate processing method further includes a substrate heating step of heating the substrate after the processing liquid removal step and before the particle removal step.

In one aspect of the present invention, it is preferable that the substrate processing method further includes a chemical liquid supplying step of supplying a chemical liquid to the upper surface of the substrate prior to the suspension supplying step, and a rinsing liquid supplying step of supplying a rinsing liquid to the upper surface of the substrate subsequent to the chemical liquid supplying step to wash away the chemical liquid. It is preferable that the suspension supplying step is performed subsequent to the rinsing liquid supplying step.

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 suspension supply unit and a control unit. The suspension supply unit supplies a suspension, which is a mixture of a processing liquid and a plurality of particles that are not dissolved in the processing liquid, to an upper surface of the substrate, thereby forming a liquid film of the suspension on the upper surface of the substrate. The control unit executes processing liquid removal control. The processing liquid removal control refers to control that removes the processing liquid from the upper surface of the substrate while causing the particles to remain (preferably accumulate) between the adjacent structures.
In one aspect of the present invention, it is preferable that the processing liquid removal control refers to control that removes the processing liquid from the upper surface of the substrate while leaving the particles between adjacent structures and supporting the structures with the particles.

In one aspect of the present invention, the substrate processing apparatus preferably further includes a particle removal unit, which preferably removes the particles remaining (preferably accumulated) between the structures by using a non-liquid.

In one aspect of the present invention, it is preferable that the particles are inorganic and the non-liquid is a vapor of a chemical liquid. It is preferable that the particle removal unit removes the particles from between the structures by supplying the vapor of the chemical liquid to the upper surface of the substrate.

In one aspect of the present invention, the particles are preferably silica.

In one aspect of the present invention, it is preferable that the particles are organic and the non-liquid is ultraviolet light or ozone. It is preferable that the particle removal unit removes the particles from between the structures by supplying the ozone to the upper surface of the substrate or by irradiating the upper surface of the substrate with the ultraviolet light.

In one aspect of the present invention, the particles are preferably polystyrene.

In one aspect of the present invention, the treatment liquid is preferably a rinse liquid.

In one aspect of the present invention, the size of the particles is preferably smaller than the distance between adjacent structures.

In one aspect of the present invention, the substrate processing apparatus preferably further includes a substrate holding unit and a substrate rotating unit. The substrate holding unit preferably holds the substrate. The substrate rotating unit preferably rotates the substrate by rotating the substrate holding unit. The processing liquid removal control preferably indicates control of rotating the substrate by the substrate rotating unit.

In one aspect of the present invention, it is preferable that the execution time of the processing liquid removal control is longer than the execution time of a predetermined process. It is preferable that the predetermined process is a process of shaking off the processing liquid, which is the same as the processing liquid and does not contain the particles, from the substrate by rotation.

In one aspect of the present invention, it is preferable to further include a substrate heating unit. The substrate heating unit preferably heats the substrate after the processing liquid removal control is executed and before the particle removal process is performed by the particle removal unit.

In one aspect of the present invention, the substrate processing apparatus preferably further includes a chemical liquid supply unit and a rinsing liquid supply unit. The chemical liquid supply unit preferably supplies a chemical liquid to the upper surface of the substrate before the suspension supply unit supplies the suspension. The rinsing liquid supply unit preferably washes away the chemical liquid by supplying a rinsing liquid to the upper surface of the substrate following the chemical liquid supply unit supplies the chemical liquid. The suspension supply unit preferably supplies the suspension to the upper surface of the substrate following the rinsing liquid supply unit supplies the rinsing liquid.

The present invention provides a substrate processing method and substrate processing apparatus that can easily allow particles to enter between structures to prevent the collapse of structures that make up a substrate pattern.

1 is a plan view showing an inside of a substrate processing apparatus according to a first embodiment of the present invention. 2 is a side view showing the inside of the processing unit according to the first embodiment. FIG. 1A is a side view showing a state in which a liquid film of the suspension according to the first embodiment covers an upper surface of a substrate, and FIG. 1A is a diagram showing a state in which the chemical liquid according to embodiment 1 covers the pattern on the substrate, FIG. 1B is a diagram showing a state in which the suspension according to embodiment 1 covers the pattern on the substrate, and FIG. 1C is a diagram showing a state in which the processing liquid is reduced from the suspension according to embodiment 1 and particles are deposited between structures constituting the pattern. 1A is a diagram showing a state in which the processing liquid has been removed from the suspension according to embodiment 1 and particles have been deposited between structures constituting a pattern on the substrate, FIG. 1B is a diagram showing a state in which the particles are being removed from between the structures according to embodiment 1, and FIG. 1C is a diagram showing a state in which the particles have been removed from between the structures according to embodiment 1. 1A is a diagram showing a state in which the chemical liquid according to embodiment 1 covers another pattern on the substrate, FIG. 1B is a diagram showing a state in which the suspension according to embodiment 1 covers a pattern on the substrate, and FIG. 1C is a diagram showing a state in which the processing liquid is reduced from the suspension according to embodiment 1 and particles are deposited between structures constituting the pattern. 1A is a diagram showing a state in which the processing liquid has been removed from the suspension according to embodiment 1 and particles have been deposited between structures constituting a pattern on the substrate, FIG. 1B is a diagram showing a state in which the particles are being removed from between the structures according to embodiment 1, and FIG. 1C is a diagram showing a state in which the particles have been removed from between the structures according to embodiment 1. 3 is a flowchart showing a substrate processing method according to the first embodiment. FIG. 11 is a side view showing the inside of a processing unit according to a second embodiment of the present invention. 10 is a flowchart showing a substrate processing method according to a second embodiment. FIG. 2 is a schematic cross-sectional view showing a particle removal unit according to an embodiment of the present invention. FIG. 4 is a schematic cross-sectional view showing a particle removal unit according to another embodiment of the present invention. FIG. 11 is a schematic cross-sectional view showing a particle removal unit according to yet another embodiment of the present invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference symbols and the description will not be repeated. For ease of explanation, a three-dimensional orthogonal coordinate system (X, Y, Z) is appropriately depicted in the drawings. In the drawings, the X-axis and Y-axis are parallel to the horizontal direction, and the Z-axis is parallel to the vertical direction.

(Embodiment 1)
A substrate processing apparatus 100 according to a first embodiment of the present invention will be described with reference to Figures 1 to 8. First, the substrate processing apparatus 100 will be described with reference to Figure 1. Figure 1 is a plan view showing the inside of the substrate processing apparatus 100. The substrate processing apparatus 100 shown in Figure 1 processes a substrate W having a pattern including a plurality of structures.

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. In the following, as an example, the substrate W is a silicon wafer.

As shown in FIG. 1, the substrate processing apparatus 100 includes multiple load ports LP, an indexer robot IR, a center robot CR, multiple processing units 1, a control device 2, multiple fluid boxes 3, a chemical cabinet 4, and a particle removal unit 5.

Each load port LP accommodates multiple stacked substrates W. The indexer robot IR transports substrates W between the load port LP and the center robot CR. The center robot CR transports substrates W between the indexer robot IR and the processing unit 1, between the indexer robot IR and the particle removal unit 5, or between the processing unit 1 and the particle removal unit 5. Each processing unit 1 treats the substrate W with a chemical solution. Each fluid box 3 accommodates fluid equipment. The chemical solution cabinet 4 accommodates a chemical solution. The particle removal unit 5 will be described later.

Specifically, a predetermined number of processing units 1 (three processing units 1 in the example of FIG. 1) are stacked vertically to form one tower TW. However, in the example of FIG. 1, one tower TW of the multiple towers TW (four towers TW in the example of FIG. 1) includes one particle removal unit 5 instead of one processing unit 1. The multiple towers TW are arranged to surround the center robot CR in a plan view. The arrangement of the particle removal units 5 is not particularly limited, and for example, the particle removal units 5 may be arranged in a dedicated space in the substrate processing apparatus 100 or outside the substrate processing apparatus 100. The substrate processing apparatus 100 may also include multiple particle removal units 5.

The multiple fluid boxes 3 correspond to multiple towers TW, respectively. The chemical liquid in the chemical liquid cabinet 4 is supplied to all processing units 1 included in the tower TW corresponding to the fluid box 3 via one of the fluid boxes 3.

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, the chemical cabinet 4, and the particle removal unit 5. The control device 2 is, for example, a computer.

The control device 2 includes a control unit 21 and a memory unit 22. The control unit 21 includes a processor such as a CPU (Central Processing Unit). The memory unit 22 includes a storage device and stores data and computer programs. Specifically, the memory 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 memory unit 22 may include removable media. The memory unit 22 corresponds to an example of a non-transitory computer-readable storage medium.

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

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

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

The chamber 11 has a generally box-like shape. The chamber 11 accommodates a spin chuck 12, a spin motor 13, a chemical nozzle 14, a nozzle moving part 15, multiple guards 16, a suspension nozzle 17, a part of the pipe 7, and a part of the pipe 9.

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

The spin motor 13 rotates the spin chuck 12 that holds the substrate W, thereby rotating the substrate W. Specifically, the spin motor 13 rotates the spin chuck 12 around the rotation axis AX1. Thus, the spin chuck 12 rotates the substrate W around the rotation axis AX1 while holding the substrate W horizontally. Specifically, the spin chuck 12 includes a spin base 121 and multiple chuck members 122. The spin base 121 is substantially disk-shaped and supports the multiple chuck members 122 in a horizontal position. The multiple chuck members 122 hold the substrate W in a horizontal position. The spin chuck 12 may be, for example, a vacuum chuck or a Bernoulli chuck that utilizes the Bernoulli effect, and is not particularly limited.

The chemical 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 nozzle 14. The valve 6 is disposed in the pipe 7. The valve 6 opens and closes the flow path of the pipe 7 to switch between supplying and stopping the supply of the chemical liquid to the chemical nozzle 14. When the valve 6 opens the flow path of the pipe 7, the chemical nozzle 14 supplies the chemical liquid toward the substrate W.

The chemical solution may be, for example, dilute hydrofluoric acid (DHF), hydrofluoric acid (HF), hydronitric acid (a mixture of hydrofluoric acid and nitric acid ( _HNO3 )), buffered hydrofluoric acid (BHF), ammonium fluoride, HFEG (a mixture of hydrofluoric acid and ethylene _glycol ), phosphoric acid ( _H3PO4 ), sulfuric acid, acetic acid, nitric acid, hydrochloric acid, ammonia water, hydrogen peroxide water, organic acids (e.g., citric acid, oxalic acid), organic alkalis (e.g., TMAH: tetramethylammonium hydroxide), sulfuric acid/hydrogen peroxide water mixture (SPM), ammonia/hydrogen peroxide water mixture (SC1), hydrochloric acid/hydrogen peroxide water mixture (SC2), surfactants, or corrosion inhibitors.

The nozzle movement unit 15 raises and lowers the chemical liquid nozzle 14 and rotates the chemical liquid nozzle 14 horizontally around the rotation axis AX2. To raise and lower the chemical liquid nozzle 14, the nozzle movement unit 15 includes, for example, a ball screw mechanism and an electric motor that provides driving force to the ball screw mechanism. The nozzle movement unit 15 also includes, for example, an electric motor to rotate the chemical liquid nozzle 14 horizontally.

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 to switch between supplying and stopping the supply 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. Note that the pipe 9 is connected to, for example, a suspension tank that stores the suspension.

A suspension is a dispersion system in which solid particles are dispersed in a liquid. A suspension is, for example, a sol. Specifically, a suspension is a substance in which a treatment liquid and a number of particles (a large number of particles) that do not dissolve in the treatment liquid are mixed together. The treatment liquid is the dispersion medium, and the particles are the dispersoid. The particles are solid particles.

The processing liquid, which is the dispersion medium of the suspension, is not particularly limited, but is typically a rinse liquid. The rinse liquid is a liquid for washing away chemicals, by-products of processing by the chemicals, and/or foreign matter from the substrate W, and is a liquid that does not chemically act on the substrate W.

The rinse liquid is, for example, deionized water (DIW), carbonated water, electrolytic ionized water, hydrogen water, ozone water, or hydrochloric acid water with a diluted concentration (for example, about 10 ppm to 100 ppm).

The processing liquid, which is the dispersion medium of the suspension, may be, for example, an organic solvent. The organic solvent is water-soluble and has a lower surface tension than the rinse liquid. 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). When the processing liquid is an organic solvent, for example, the suspension is supplied to the substrate W after the chemical solution is washed off from the substrate W with a rinse liquid.

The particles, which are the dispersoid of the suspension, are solids that do not dissolve in the treatment liquid, which is the dispersion medium. The particles are, for example, inorganic or organic. If the particles are inorganic, the particles are, for example, silica, silicon, or silicon nitride. Silica is, for example, a silicon oxide such as silicon dioxide. If the particles are organic, the particles are, for example, polystyrene. If the particles are polystyrene, the suspension is, for example, polystyrene latex.

In addition, for example, the suspension nozzle 17 can be raised and lowered or rotated horizontally by a nozzle moving unit (not shown) having a configuration similar to that of the nozzle moving unit 15.

Each guard 16 has a generally cylindrical shape. Each guard 16 receives the chemical solution or suspension discharged from the substrate W.

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

As shown in FIG. 3(a), the suspension nozzle 17 supplies the suspension 25 to the upper surface of the substrate W, thereby forming a liquid film 26 of the suspension 25 on the upper surface of the substrate W.

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.

Continuing to refer to FIG. 3(b), the principle by which the processing liquid constituting the suspension 25 is removed from the substrate W and the particles constituting the suspension 25 remain on the substrate W will be described. When removing the processing liquid from the suspension 25, the supply of the suspension 25 from the suspension nozzle 17 to the substrate W is stopped, and the substrate W is rotated.

When the substrate W on which the liquid film 26 is formed is rotated, the suspension 25 present in the region 261 of the liquid film 26 flows due to centrifugal force. 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 processing liquid in the suspension 25 mainly evaporates, and the liquid level of the liquid film 26 drops. Therefore, the particles in the suspension 25 are pushed down by the liquid level. Therefore, many particles dispersed in the processing liquid are deposited on the upper surface of the substrate W. As the evaporation of the processing liquid further progresses, the processing liquid is removed from the substrate W, and many deposited particles remain on the upper surface of the substrate W.

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

Next, the substrate processing method according to the first embodiment of the present invention will be described with reference to Figs. 1, 2, 4, and 5. Fig. 4(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 supplying process. Fig. 4(b) is a diagram showing a state in which the suspension liquid 25 covers the pattern PT of the substrate W in the suspension supplying process. Fig. 4(c) is a diagram showing a state in which the processing liquid 251 is reduced from the suspension liquid 25 and particles are deposited between the structures 23 constituting the pattern PT in the processing liquid removing process. Fig. 5(a) is a diagram showing a state in which the processing liquid 251 is removed from the suspension liquid 25 after the processing liquid removing process is completed and particles 252 are deposited between the structures 23 constituting the pattern PT of the substrate W. Fig. 5(b) is a diagram showing a state in which the particles 252 are being removed from between the structures 23 in the particle removing process. Fig. 5(c) is a diagram showing a state in which the particles 252 are being removed from between the structures 23 after the particle removing process is completed.

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 concave-convex pattern. The pattern PT includes a plurality of structures 23. The structures 23 are, for example, microstructures. The aspect ratio AR of the structures 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.

The first direction D1 indicates a direction that intersects with the substrate W. In the example of FIG. 4(a), the first direction D1 indicates a direction that is approximately perpendicular to the substrate W. The second direction D2 intersects with the first direction D1. In the example of FIG. 4(a), the second direction D2 is approximately perpendicular to the first direction D1.

Of the multiple structures 23, the distance G between adjacent structures 23 is, for example, 10 nm or more and 100 nm or less.

As an example, the structure 23 extends along the first direction D1. Note that FIG. 4(a) merely shows a schematic representation of the structure 23, and the structure 23 may have any shape and configuration depending on the intended use of the substrate W.

For example, the structure 23 is composed of a single layer or multiple 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 multiple 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.

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, for example, a film containing at least one of titanium, tungsten, copper, and aluminum.

As shown in FIG. 2 and FIG. 4(a), first, in the chemical supplying step, the chemical nozzle 14 supplies the chemical 27 to the upper surface of the substrate W. As a result, the substrate W is treated with the chemical.

Next, as shown in FIG. 2 and FIG. 4(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. The suspension 25 is a mixture of a processing liquid 251 and a plurality of particles 252 (a large number of particles). In the suspension 25, the plurality of particles 252 are dispersed in the processing liquid 251. The particles 252 prevent the structure 23 from collapsing when the substrate W is dried. This point will be described in detail later.

The particle size of the particles 252 is smaller than the distance G between adjacent structures 23. Therefore, according to embodiment 1, the particles 252 can easily enter between the structures 23.

The particle diameter (size) of the particle 252 is, for example, several nm or more and several tens of nm or less. For example, the particle diameter of the particle 252 is 20 nm.

The density of the particles 252 in the suspension 25 is, for example, a volume fraction of 0.1 or more and 0.9 or less. The density of the particles 252 in the suspension 25 is, for example, a value at which the particles 252 can occupy "M/10" or more of the space SP between the structures 23 at the completion of the treatment liquid removal process (FIGS. 4(c) and 5(a)). 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 particles 252 occupying the space SP between the structures 23 at the completion of the treatment liquid removal process (FIGS. 4(c) and 5(a)), the more effectively the collapse of the structures 23 can be suppressed. Details of this point will be described later.

Next, as shown in FIG. 4(c), in the treatment liquid removal step, the treatment liquid 251 is removed (removed) from the upper surface of the substrate W so that particles 252 remain between adjacent structures 23. In this case, the treatment liquid 251 is evaporated in the region 262 shown in FIG. 3(b), causing the liquid level 251a of the treatment liquid 251 (suspension 25) to descend. Then, particles 252 remain between adjacent structures 23. Therefore, according to the first embodiment, when the treatment liquid 251 is removed from the substrate W, the particles 252 support the structures 23. As a result, the collapse of the structures 23 due to the surface tension of the treatment liquid 251 can be suppressed.

Specifically, at least during the period during which the processing liquid 251 between the structures 23 is vaporized (removed) (hereinafter referred to as "period T"), a plurality of 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 particles 252 are spread between the structures 23. In other words, at least during period T, a plurality of particles 252 are filled between the structures 23. Therefore, a plurality of structures 23 are supported by a plurality of particles 252. As a result, when the processing liquid 251 is removed from the substrate W, it is possible to prevent the structures 23 from collapsing due to the surface tension of the processing liquid 251.

In particular, in the first embodiment, as shown in FIG. 4(b), the suspension 25 is supplied to the upper surface of the substrate W. At this stage, the particles 252 have already penetrated between the structures 23. Then, as shown in FIG. 4(c), the processing liquid 251 is removed from the suspension 25. In this case, the particles 252 are pushed down toward the pattern PT by the lowering of the liquid surface 251a of the processing liquid 251 (suspension 25). As a result, the particles 252 for suppressing the collapse of the structures 23 constituting the pattern PT of the substrate W can easily penetrate and be deposited between the structures 23. In other words, the processing liquid 251 allows the particles 252 to easily penetrate and be deposited between the structures 23.

Specifically, in the treatment liquid removal step, the treatment liquid 251 is removed from the substrate W by rotating the substrate W while the supply of the suspension 25 is stopped. Therefore, according to the first embodiment, the treatment liquid 251 can be easily removed from the substrate W with a simple configuration.

Also, for example, the execution time of the processing liquid removal process is longer than the execution time of the predetermined process (hereinafter referred to as "predetermined process ST"). The predetermined process ST refers to a process of shaking off the processing liquid, which is the same processing liquid as the processing liquid 251 but does not contain particles 252, from the substrate by rotation. The reason that the execution time of the processing liquid removal process is longer than the execution time of the predetermined process ST is that the processing liquid 251 contains particles 252 and therefore takes more time to remove than processing liquid not containing particles. In embodiment 1, the execution time of the processing liquid removal process is longer than the execution time of the predetermined process ST, so that the processing liquid can be more reliably removed from the substrate W.

When the processing liquid 251 is a rinsing liquid, the "predetermined process ST" is a rinsing process (rinsing liquid supply process), and the "processing liquid that is the same as the processing liquid 251 and does not contain particles 252" is the rinsing liquid. The "rinsing process (rinsing liquid supply process)" refers to a process of washing away chemical liquid, by-products of processing by the chemical liquid, and/or foreign matter from the substrate W.

Specifically, in the processing liquid removal process, the control unit 21 shown in FIG. 2 executes processing liquid removal control. The processing liquid removal control refers to control for removing the processing liquid 251 from the upper surface of the substrate W while leaving particles 252 between 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 processing liquid removal control refers to control for rotating the substrate W by the spin motor 13. And, for example, the execution time of the processing liquid removal control is longer than the execution time of the specified process ST.

Here, in the treatment liquid removal process, the particles 252 are allowed to remain in the space SP between the structures 23 so that the particles 252 occupy at least "M/10" 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".

Next, as shown in FIG. 5(a), when the treatment liquid removal process is completed, the treatment liquid 251 is removed and particles 252 remain between adjacent structures 23. In the example of FIG. 5(a), a plurality of particles 252 are deposited between structures 23. In other words, a plurality of particles 252 are spread between structures 23. In further other words, a plurality of particles 252 are filled between structures 23.

Next, as shown in FIG. 1 and FIG. 5(b), in the particle removal process, the particle removal unit 5 uses a non-liquid to remove particles 252 remaining between the structures 23 that make up the pattern PT. As a result, in embodiment 1, the particles 252 can be removed from the substrate W while maintaining the substrate W in a dry state.

First to third examples of the particle removal process will be described. In the first example, the particles 252 constituting the suspension 25 are inorganic, and the processing liquid 251 constituting the suspension 25 is a rinsing liquid. In this case, the particle removal unit 5 removes the particles 252 remaining between the structures 23 by gas-phase cleaning (vapor cleaning). Specifically, the particle removal unit 5 removes the particles 252 from between the structures 23 by supplying a vapor of a non-liquid (gas) chemical liquid to the upper surface of the substrate W. According to the first embodiment, the particles 252, which are inorganic, can be effectively removed from the substrate W by the vapor of the chemical liquid. For example, when the processing liquid 251 is a rinsing liquid and the particles 252 are silica, the particle removal unit 5 removes the particles 252 (silica) from between the structures 23 by supplying a vapor of hydrofluoric acid to the upper surface of the substrate W. Details of this point will be described later with reference to FIG. 11.

In the second example, the particles 252 constituting the suspension 25 are organic matter, and the processing liquid 251 constituting the suspension 25 is a rinsing liquid. In this case, the particle removal unit 5 removes the particles 252 from between the structures 23 by supplying ozone, which is a non-liquid (gas), to the upper surface of the substrate W. According to the first embodiment, the particles 252, which are organic matter, are oxidized and decomposed by ozone, so that the particles 252 can be effectively removed from the substrate W. For example, when the processing liquid 251 is a rinsing liquid and the particles 252 are polystyrene, that is, when the suspension 25 is polystyrene latex, the particle removal unit 5 removes the particles 252 (polystyrene) from between the structures 23 by supplying ozone to the upper surface of the substrate W. Details of this point will be described later with reference to FIG. 12.

In the third example, the particles 252 constituting the suspension 25 are organic matter, and the processing liquid 251 constituting the suspension 25 is a rinsing liquid. In this case, the particle removal unit 5 removes the particles 252 from between the structures 23 by irradiating the upper surface of the substrate W with ultraviolet light, which is a non-liquid (electromagnetic wave). According to the first embodiment, the particles 252, which are organic matter, can be effectively removed from the substrate W by oxidizing and decomposing the particles 252 with ultraviolet light. For example, when the processing liquid 251 is a rinsing liquid and the particles 252 are polystyrene, that is, when the suspension 25 is polystyrene latex, the particle removal unit 5 removes the particles 252 (polystyrene) from between the structures 23 by irradiating the upper surface of the substrate W with ultraviolet light. Details of this point will be described later with reference to FIG. 13.

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

Here, other examples of the pattern PT of the substrate W will be described with reference to Figures 1, 2, 6 and 7. Figure 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 process. Figure 6(b) is a diagram showing a state in which the suspension liquid 25 covers the pattern PT of the substrate W in the suspension liquid supply process. Figure 6(c) is a diagram showing a state in which the processing liquid 251 is reduced from the suspension liquid 25 and particles are deposited between the structures 23 constituting the pattern PT in the processing liquid removal process. Figure 7(a) is a diagram showing a state in which the processing liquid 251 is removed from the suspension liquid 25 after the processing liquid removal process is completed and particles 252 are deposited between the structures 23 constituting the pattern PT of the substrate W. Figure 7(b) is a diagram showing a state in which the particles 252 are being removed from between the structures 23 in the particle removal process. Figure 7(c) is a diagram showing a state in which the particles 252 are removed from between the structures 23 after the particle removal process is completed. Below, we will mainly explain the differences from the content explained with reference to Figures 4 and 5.

As shown in FIG. 6(a), the substrate W has a pattern PT. In the pattern PT, each of the multiple structures 23 has a structure 241 and multiple protrusions 242.

As an example, the structure 241 extends along the first direction D1. The protrusions 242 protrude from the structure 241 along the second direction D2. The multiple protrusions 242 are formed at intervals in the first direction D1. Therefore, a space SPX exists between the protrusions 242 that face each other in the second direction D2. Note that FIG. 6(a) merely shows a schematic representation of the structure 23, and the structure 23 may have any shape and configuration depending on the intended use of the substrate W.

As shown in FIG. 2 and FIG. 6(a), first, in the chemical supplying step, the chemical nozzle 14 supplies the chemical 27 to the upper surface of the substrate W. As a result, the substrate W is treated with the chemical.

2 and 6(b), in the suspension supplying 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.

The particle size of the particles 252 is smaller than the distance G between adjacent structures 23. Therefore, during the suspension supply process, the particles 252 penetrate between the structures 23. The distance G indicates, for example, the distance between the closest portions of the structures 23 adjacent to each other in the first direction D1.

6(c), in the treatment liquid removal step, the treatment liquid 251 is removed from the upper surface of the substrate W so that particles 252 remain between adjacent structures 23. For example, in the treatment liquid removal step, the treatment liquid 251 is removed from the substrate W by rotating the substrate W with the supply of the suspension 25 stopped.

In the treatment liquid removal process, the treatment liquid 251 evaporates in the region 262 shown in FIG. 3B, causing the liquid surface 251a of the treatment liquid 251 (suspension 25) to descend. Then, particles 252 remain between the structures 23 adjacent to each other in the first direction D1. Furthermore, particles 252 remain between the convex portions 242 adjacent to each other in the second direction D2. Therefore, according to the first embodiment, when the treatment liquid 251 is removed from the substrate W, the particles 252 support not only the structures 241 but also the convex portions 242. As a result, it is possible to prevent the structures 241 and the convex portions 242 from collapsing due to the surface tension of the treatment liquid 251.

Specifically, during the period T during which the processing liquid 251 between at least the structures 23 is vaporized (removed), a plurality of particles 252 are deposited between the structures 23 adjacent to each other in the first direction D1 over the entire region of the substrate W in which the pattern PT is formed, and a plurality of 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 particles 252 are spread between the structures 23 and between the convex portions 242. Therefore, the structures 241 and the convex portions 242 of the structures 23 are supported by a plurality of particles 252. As a result, when the processing liquid 251 is removed from the substrate W, the collapse of the structures 241 and the convex portions 242 due to the surface tension of the processing liquid 251 can be suppressed.

In particular, in the first embodiment, as shown in FIG. 6B, the suspension 25 is supplied to the upper surface of the substrate W. At this stage, the particles 252 have already penetrated 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. 6C, the processing liquid 251 is removed from the suspension 25. In this case, the particles 252 are pushed down toward the pattern PT by the lowering of the liquid surface 251a of the processing liquid 251 (suspension 25). As a result, the particles 252 can easily penetrate and be deposited between the structures 23 and 23, and can easily penetrate and fill between the convex portions 242 and 242.

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

Next, as shown in FIG. 1 and FIG. 7(b), in the particle removal process, the particle removal unit 5 uses a non-liquid to remove particles 252 remaining between the structures 23 and between the protrusions 242 that constitute the pattern PT. As a result, in embodiment 1, the particles 252 can be removed from the substrate W while maintaining the substrate W in a dry state.

Next, as shown in FIG. 7(c), when the particle removal process is completed, particles 252 are removed from between structures 23 and between protrusions 242.

As described above with reference to Figures 4 to 7, the suspension supply process, processing liquid removal process, and particle removal process can dry the substrate W after processing with the chemical liquid while preventing the collapse of the structures 23 in the pattern PT of the substrate W.

Here, a reference example is described in which the substrate W is dried while suppressing the collapse of the structure 23. In the first reference example, an organic solvent (e.g., IPA) and/or a hydrophobizing agent that does not contain particles 252 is used to suppress the collapse of the structure 23 caused by the surface tension of the rinse liquid. However, there is a demand for a technology that more effectively suppresses the collapse of the structure 23.

In the second reference example, the substrate W after being treated with a chemical solution is dried by a sublimation technique. In the sublimation technique, after treating the substrate W with a chemical solution, the pattern PT is covered with a sublimable substance. The sublimable substance is then sublimated into a gas to dry the substrate W. Specifically, when covering the pattern PT with a sublimable substance, it is necessary to replace the chemical solution with a sublimable substance. In this case, for example, the sublimable substance is replaced with the chemical solution in a liquid state, and then cooled to make the sublimable substance solid. Alternatively, for example, the organic solvent is volatilized to precipitate the sublimable substance and make it solid. However, in the second reference example, for example, freezing point depression occurs in the gaps of the nano-order structure 23, so that the sublimable substance does not become solid, or the optimal concentration of the sublimable substance changes depending on the type of pattern PT, and depending on the situation, the performance of the sublimable substance may not be stable.

In contrast, in embodiment 1, suspension 25 is supplied to the substrate W after processing with the chemical liquid, and the particles 252 constituting suspension 25 support the structures 23 of the pattern PT when the substrate W is dried. In other words, when the substrate W is dried, the structures 23 are physically supported by the particles 252. As a result, compared to the first reference example, collapse of the structures 23 is more effectively suppressed. In addition, because a simple method is used in which the particles 252 are deposited between the structures 23 by lowering the processing liquid 251, the performance for suppressing collapse of the structures 23 is more stable compared to the second reference example.

Next, the substrate processing method according to the first embodiment will be described with reference to Figures 1, 2, and 8. 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. Figure 6 is a flowchart showing the substrate processing method. As shown in Figure 6, the substrate processing method includes steps S1 to S8. Steps S1 to S8 are executed according to the control of the control unit 21.

As shown in Figures 1, 2, and 8, in step S1, the center robot CR loads the substrate W into the processing unit 1. Then, in the processing unit 1, the spin chuck 12 holds the substrate W. Furthermore, the spin motor 13 rotates the spin chuck 12 to rotate the substrate W.

Next, in step S2, the chemical nozzle 14 supplies the chemical to the upper surface of the rotating substrate W. Step S2 corresponds to an example of the "chemical supply step" of the present invention.

Next, in step S3, the suspension nozzle 17 supplies the suspension 25 onto the upper surface of the rotating substrate W, thereby forming a liquid film 26 of the suspension 25 on the upper surface of the substrate W. Step S3 corresponds to an example of the "suspension supply step" of the present invention.

In particular, when the processing liquid 251 constituting the suspension 25 is a rinsing liquid, step S3 also functions as a rinsing step, because the chemical liquid is washed away by the suspension 25. Therefore, in this case, the rinsing step can be omitted, and the number of steps required to process the substrate W can be reduced.

Next, in step S4, the processing liquid 251 is removed from the upper surface of the substrate W so that particles 252 remain between adjacent structures 23 on the substrate W. That is, in step S4, the control unit 21 executes processing liquid removal control. Step S4 corresponds to an example of the "processing liquid removal step" of the present invention.

Specifically, in step S4, the spin motor 13 rotates the spin chuck 12 to rotate the substrate W. In this case, in the range of region 261 in FIG. 3B, the suspension 25 is removed from the substrate W by the flow of the suspension 25 due to the centrifugal force. In the range of region 262 in FIG. 3B, the processing liquid 251 constituting the suspension 25 is vaporized, and the processing liquid 251 is removed from the substrate W. In this case, at least during the period T in which the processing liquid 251 is vaporized from between the structures 23, the particles 252 remain between the structures 23. That is, the particles 252 are deposited between the structures 23. As a result, according to the first embodiment, the structure 23 is supported by the particles 252, and therefore the collapse of the structure 23 due to the surface tension of the processing liquid 251 can be suppressed. In addition, in the first embodiment, the processing liquid 251 can easily allow the particles 252 to enter between the structures 23.

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. After performing step S4 for a predetermined period, the spin motor 13 stops the rotation of the spin chuck 12, thereby stopping the rotation of the substrate W. The predetermined period is, for example, determined experimentally and/or empirically.

Next, in step S5, the center robot CR removes the substrate W from the processing unit 1.

Next, in step S6, the center robot CR transports the substrate W into the particle removal unit 5.

Next, in step S7, the particle removal unit 5 uses a non-liquid to remove particles 252 remaining between the structures 23 on the substrate W.

Next, in step S8, the center robot CR removes the substrate W from the particle removal unit 5. Then, the substrate processing method ends.

As described above with reference to FIG. 8, according to the substrate processing method of embodiment 1, steps S3, S4, and S7 can dry the substrate W after processing with the chemical solution while preventing the collapse of the structures 23 in the pattern PT of the substrate W.

(Embodiment 2)
A substrate processing apparatus 100 according to a second embodiment of the present invention will be described with reference to Figures 9 and 10. The main difference between the second embodiment and the first embodiment is that the substrate processing apparatus 100 according to the second embodiment executes a rinsing liquid supplying step before a suspension supplying step. Otherwise, the overall configuration of the substrate processing apparatus 100 according to the second embodiment is similar to the overall configuration of the substrate processing apparatus 100 according to the first embodiment described with reference to Figure 1. Below, the differences between the second embodiment and the first embodiment will be mainly described.

Figure 9 is a side view showing the inside of the processing unit 1 according to the second embodiment. As shown in Figure 9, the processing unit 1 according to the second embodiment includes a rinse liquid nozzle 31 in addition to the configuration of the processing unit 1 according to the first embodiment shown in Figure 2. The processing unit 1 according to the second embodiment may further include a substrate heating unit 34. Furthermore, the substrate processing apparatus 100 according to the second embodiment includes a pipe 32 and a valve 33 in addition to the configuration of the substrate processing apparatus 100 according to the first embodiment shown in Figure 1.

The rinsing liquid nozzle 31 supplies rinsing liquid to the upper surface of the substrate W. Specifically, a pipe 32 supplies rinsing liquid to the rinsing liquid nozzle 31. A valve 33 is disposed in the pipe 32. The valve 33 opens and closes the flow path of the pipe 32, switching between supplying and stopping the supply of rinsing liquid to the rinsing liquid nozzle 31. When the valve 33 opens the flow path of the pipe 32, the rinsing liquid nozzle 31 supplies rinsing liquid toward the substrate W. The rinsing liquid nozzle 31 corresponds to an example of a "rinsing liquid supply unit" in the present invention.

In addition, for example, the rinsing liquid nozzle 31 can be raised and lowered or rotated horizontally by a nozzle moving unit (not shown) having a configuration similar to that of the nozzle moving unit 15.

The substrate heating section 34 heats the substrate W. In the example of FIG. 9, the substrate heating section 34 is spaced apart from the substrate W and heats the substrate W from below. Specifically, the substrate heating section 34 is disposed between the spin base 121 and the substrate W. The substrate heating section 34 has a generally circular disk shape. The substrate heating section 34 is, for example, a heater that generates heat when electricity is applied. The heater has, for example, a heating element (for example, a resistor). The substrate W may also be heated from above the substrate W.

Next, a substrate processing method according to the second embodiment will be described with reference to Figs. 1, 9, and 10. Fig. 10 is a flowchart showing the substrate processing method. As shown in Fig. 10, the substrate processing method includes steps S11 to S20. Steps S11 to S20 are performed according to the control of the control unit 21.

As shown in Figures 1, 9, and 10, in step S11, the center robot CR loads the substrate W into the processing unit 1. Otherwise, step S11 is the same as step S1 in Figure 8.

Next, in step S12, the chemical nozzle 14 supplies the chemical liquid to the upper surface of the rotating substrate W. That is, before steps S13 and S14, the chemical nozzle 14 supplies the chemical liquid to the upper surface of the rotating substrate W. Specifically, before the supply of rinsing liquid by the rinsing liquid nozzle 31 and the supply of suspension liquid 25 by the suspension nozzle 17, the chemical nozzle 14 supplies the chemical liquid to the upper surface of the rotating substrate W. Otherwise, step S12 is similar to step S2 in FIG. 8. Step S12 corresponds to an example of the "chemical liquid supply step" of the present invention.

Next, in step S13, the rinsing liquid nozzle 31 supplies rinsing liquid to the upper surface of the rotating substrate W, thereby washing the chemical liquid away from the substrate W. In other words, following the chemical liquid supply process by the chemical liquid nozzle 14, the rinsing liquid nozzle 31 supplies rinsing liquid to the upper surface of the rotating substrate W, thereby washing the chemical liquid away from the substrate W. Step S13 corresponds to an example of the "rinsing liquid supply step" of the present invention.

Next, in step S14, the suspension nozzle 17 supplies the suspension 25 onto the upper surface of the rotating substrate W, thereby forming a liquid film 26 of the suspension 25 on the upper surface of the substrate W. That is, following the supply process of the rinsing liquid by the rinsing liquid nozzle 31, the suspension nozzle 17 supplies the suspension 25 onto the upper surface of the substrate W. Otherwise, step S14 is similar to step S3 in FIG. 8. Step S14 corresponds to an example of the "suspension supplying step" of the present invention.

In particular, when the processing liquid 251 constituting the suspension 25 is a rinsing liquid, the chemical liquid can be more effectively discharged from the substrate W in combination with step S13.

Next, in step S15, the processing liquid 251 is removed from the upper surface of the substrate W so that particles 252 remain between adjacent structures 23 on the substrate W. That is, in step S15, the control unit 21 executes processing liquid removal control. Otherwise, step S15 is similar to step S4 in FIG. 8. Step S15 corresponds to an example of the "processing liquid removal step" of the present invention.

Next, in step S16, the substrate heating section 34 heats the rotating substrate W. That is, the substrate heating section 34 heats the substrate W after step S14 and before step S19. Specifically, the substrate W is heated after the processing liquid removal control is performed and before the particle removal unit 5 removes the particles 252. This makes it possible to more reliably dry the substrate W. Step S16 corresponds to an example of the "substrate heating step" of the present invention.

When step S16 has been performed for a predetermined period, the spin motor 13 stops the rotation of the spin chuck 12, thereby stopping the rotation of the substrate W. The predetermined period is determined experimentally and/or empirically. Note that steps S15 and S16 may be performed in parallel.

Next, in step S17, the center robot CR removes the substrate W from the processing unit 1.

Next, in step S18, the center robot CR transports the substrate W into the particle removal unit 5.

Next, in step S19, the particle removal unit 5 uses a non-liquid to remove particles 252 remaining between the structures 23 on the substrate W.

Next, in step S20, the center robot CR removes the substrate W from the particle removal unit 5. Then, the substrate processing method ends.

As described above with reference to FIG. 10, according to the substrate processing method of embodiment 2, the substrate W after processing with the chemical liquid can be dried by steps S14, S15, S16, and S19 while suppressing collapse of the structures 23 in the pattern PT of the substrate W. Note that the substrate processing method does not have to include step S16.

Next, three specific examples of the particle removal unit 5 used in the first and second embodiments will be described with reference to Figures 11 to 13.

[Removal of particles 252 with hydrofluoric acid vapor]
Fig. 11 is a schematic cross-sectional view showing a particle removal unit 5 according to an embodiment of the present invention. In the case where the processing liquid 251 constituting the suspension 25 is a rinse liquid and the particles 252 constituting the suspension 25 are silica, the particle removal unit 5 shown in Fig. 11 removes the particles 252 from between the structures 23 of the substrate W by supplying steam of hydrofluoric acid to the upper surface of the substrate W from which the processing liquid 251 has been removed. Note that the substrate W is carried into the particle removal unit 5 in step S6 of Fig. 8 or step S18 of Fig. 10. Therefore, the substrate W processed by the particle removal unit 5 is the substrate W (Fig. 5(a) or Fig. 7(a)) in a state in which the processing liquid 251 (rinse liquid) of the suspension 25 has been removed and the particles 252 (silica) have been deposited.

As shown in FIG. 11, the particle removal unit 5 is a vapor processing unit that supplies a vapor containing hydrogen fluoride, which is an example of a processing vapor, to the substrate W. The particle removal unit 5 includes an HF vapor generating container 4A that stores hydrofluoric acid (liquid), and a chamber 5A having an enclosed space SP1 therein that houses the HF vapor generating container 4A. The hydrofluoric acid in the HF vapor generating container 4A is heated by an HF heater 6A built into the HF vapor generating container 4A. The temperature of the hydrofluoric acid in the HF vapor generating container 4A is controlled by the control unit 21.

The particle removal unit 5 includes a punching plate 7A disposed below the HF vapor generating container 4A and a hot plate 8A disposed below the punching plate 7A. The hot plate 8A holds the substrate W horizontally at a substrate holding position (position shown in FIG. 11) where the upper surface of the substrate W faces the punching plate 7A. The substrate W is supported while being heated by the hot plate 8A. The temperature of the substrate W is maintained at a constant temperature by the control unit 21. The hot plate 8A is connected to the upper end of the rotating shaft 9A. A rotating drive mechanism 10A including a motor and the like is connected to the rotating shaft 9A. When the rotating drive mechanism 10A rotates the rotating shaft 9A, the hot plate 8A rotates together with the rotating shaft 9A around the vertical axis. As a result, the substrate W held by the hot plate 8A rotates around the vertical rotating axis Aa passing through the center of the substrate W.

The particle removal unit 5 further includes a cylindrical bellows 11A arranged around the hot plate 8A, and an expansion unit (not shown) that expands and contracts the bellows 11A up and down. The hot plate 8A is arranged inside the bellows 11A. The expansion unit expands and contracts the bellows 11A between a sealed position (position shown by a solid line) where the upper edge of the bellows 11A abuts against the punching plate 7A and the space around the hot plate 8A is sealed, and a retracted position (position shown by a two-dot chain line) where the upper edge of the bellows 11A is retracted below the top surface of the hot plate 8A.

The HF vapor generating container 4A includes a vapor generating space SP2 filled with hydrofluoric acid vapor (gas generated by evaporation of hydrofluoric acid) and a flow path 15A connected to the vapor generating space SP2 via a communication valve 14A. The HF vapor generating container 4A is connected to a first pipe 18A in which a first flow controller 16A and a first valve 17A are interposed. The HF vapor generating container 4A is connected to a first nitrogen gas supply source 19A via the first pipe 18A. Nitrogen gas, which is an example of an inert gas, is supplied to the vapor generating space SP2 via the first pipe 18A. Similarly, the flow path 15A is connected to a second pipe 22A in which a second flow controller 20A and a second valve 21A are interposed. The flow path 15A is connected to a second nitrogen gas supply source 23A via the second pipe 22A. Nitrogen gas is supplied to the flow path 15A via the second pipe 22A.

The communication valve 14A, the first valve 17A, and the second valve 21A are opened and closed by the control unit 21. When the communication valve 14A and the first valve 17A are open, the hydrofluoric acid vapor floating in the vapor generation space SP2 is supplied to the flow path 15A through the communication valve 14A by the flow of nitrogen gas from the first nitrogen gas supply source 19A. Therefore, when all the valves 14A, 17A, and 21A are open, the HF vapor (gas containing hydrofluoric acid vapor and nitrogen gas) supplied to the flow path 15A is guided to the punching plate 7A by the flow of nitrogen gas from the second nitrogen gas supply source 23A. Therefore, the HF vapor passes through a large number of through holes formed in the punching plate 7A and is sprayed onto the upper surface of the substrate W held on the hot plate 8A. As a result, particles 252 (silica) deposited between structures 23 on the substrate W are removed from between structures 23 (FIGS. 5(b), 5(c), 7(b), 7(c)).

When only the second valve 21A is open, only nitrogen gas is guided to the punching plate 7A. As a result, the nitrogen gas is sprayed onto the upper surface of the substrate W. The substrate processing apparatus 100 further includes an exhaust unit 24A (exhaust means) that exhausts gas from within the chamber 5A.

[Removal of particles 252 by ozone]
Fig. 12 is a schematic cross-sectional view showing a particle removal unit 5 according to another embodiment of the present invention. When the suspension 25 is polystyrene latex, the particle removal unit 5 shown in Fig. 12 removes particles 252 (polystyrene) from between the structures 23 of the substrate W by supplying ozone to the upper surface of the substrate W from which the processing liquid 251 of the suspension 25 has been removed. Note that the substrate W is loaded into the particle removal unit 5 in step S6 of Fig. 8 or step S18 of Fig. 10. Therefore, the substrate W processed by the particle removal unit 5 is the substrate W (Fig. 5(a) or Fig. 7(a)) in a state in which the processing liquid 251 (rinsing liquid) of the suspension 25 has been removed and particles 252 (polystyrene) have accumulated.

As shown in FIG. 12, the particle removal unit 5 includes a chamber 2B, a lid lifting mechanism 31B, a hot plate 4B, a plurality of lift pins 51B, a pin lifting mechanism 32B, an ozone gas supply unit 6B, a gas exhaust unit 71B, and a concentration measurement unit 72B. The control unit 21 is responsible for the overall control of the particle removal unit 5.

The chamber 2B comprises a chamber body 21B and a chamber lid 22B. The chamber body 21B comprises a disk-shaped bottom plate 211B and a cylindrical body side 212B. The chamber lid 22B comprises a disk-shaped top plate 221B and a cylindrical lid side 222B. A shower plate 223B extending in the horizontal direction is fixed to the underside of the top plate 221B via a plate support 224B. A large number of through holes are formed in the shower plate 223B. An O-ring 23B is provided between the lid side 222B and the body side 212B.

The lid lifting mechanism 31B raises and lowers the chamber lid 22B in the vertical direction. In FIG. 12, the bottom end surface of the lid side 222B and the top end surface of the body side 212B are almost in contact, and the top of the chamber body 21B is closed by the chamber lid 22B. In the state of FIG. 12, the space between the bottom end surface of the lid side 222B and the top end surface of the body side 212B is sealed by an O-ring 23B, and a processing space 20B that is isolated from the outside is formed inside the chamber 2B. The lid lifting mechanism 31B may use, for example, a motor or an actuator other than a motor.

The hot plate 4B is placed in the processing space 20B. A heater 40B including an electric heating wire is provided on the hot plate 4B. The heater 40B heats the hot plate 4B to a predetermined set temperature. The hot plate 4B is fixed to the chamber body 21B. The central axes of the disk-shaped bottom plate portion 211B, top plate portion 221B, and hot plate 4B are approximately the same. In the following description, the circumferential direction about the central axis is simply referred to as the "circumferential direction."

The hot plate 4B has a plurality of through holes 41B arranged at regular angular intervals in the circumferential direction. The bottom plate portion 211B has through holes 213B at positions overlapping with the through holes 41B in the vertical direction. Each of the plurality of lift pins 51B is inserted into any combination of the through holes 41B and the through holes 213B. The lower ends of the plurality of lift pins 51B are fixed to the pin support plate 52B. Below the bottom plate portion 211B, the periphery of each lift pin 51B is surrounded by a bellows 53B.

The pin lifting mechanism 32B includes a stepping motor and raises and lowers the pin support plate 52B in the vertical direction. As a result, the multiple lift pins 51B move in the vertical direction. In FIG. 12, the tips (upper ends) of the multiple lift pins 51B are positioned inside the through holes 41B of the hot plate 4B. The pin lifting mechanism 32B may use, for example, other types of motors or actuators other than motors.

In the particle removal unit 5, when the tips of the multiple lift pins 51B are positioned inside the through holes 41B, the substrate W is placed on the upper surface of the hot plate 4B and held in a horizontal position. Hereinafter, this holding state is referred to as the "first holding state." Also, when the tips of the multiple lift pins 51B are positioned above the upper surface of the hot plate 4B, the substrate W is supported from below by the multiple lift pins 51B and held in a horizontal position. Hereinafter, this holding state is referred to as the "second holding state."

The ozone gas supply unit 6B includes an ozone gas supply source 61B, a gas supply pipe 62B, a gas supply valve 63B, and a gas nozzle 64B. The gas nozzle 64B has a gas supply port 641B. The gas nozzle 64B is connected to the ozone gas supply source 61B via the gas supply pipe 62B. By opening the gas supply valve 63B, ozone ( _O3 ) gas is supplied from the gas supply port 641B of the gas nozzle 64B to the processing space 20B.

The ozone gas passes through a large number of through-holes in the shower plate 223B and is uniformly supplied to the upper surface 91B of the substrate W. The ozone gas is, for example, ozone diluted with a specific gas. The ozone gas may be mixed with other types of oxidizing gases, etc.

Specifically, in the first holding state or the second holding state, ozone gas is supplied to the upper surface 91B of the substrate W. As a result, particles 252 (polystyrene) deposited between the structures 23 of the substrate W are oxidized and decomposed by the ozone, and are removed from between the structures 23 (FIGS. 5(b), 5(c), 7(b), and 7(c)).

The gas exhaust unit 71B includes a gas exhaust port 711B and a gas exhaust pipe 712B. Gas in the processing space 20B is exhausted to the outside via the gas exhaust port 711B and the gas exhaust pipe 712B. A concentration measurement unit 72B is connected to the gas exhaust pipe 712B. The concentration measurement unit 72B measures the concentration of a specific component in the gas (exhaust gas) exhausted from the processing space 20B.

[Removal of particles 252 by ultraviolet light]
Fig. 13 is a schematic cross-sectional view showing a particle removal unit 5 according to still another embodiment of the present invention. When the suspension 25 is polystyrene latex, the particle removal unit 5 shown in Fig. 13 irradiates ultraviolet light onto the upper surface of the substrate W from which the processing liquid 251 of the suspension 25 has been removed, thereby removing particles 252 (polystyrene) from between the structures 23 of the substrate W. Note that the substrate W is loaded into the particle removal unit 5 in step S6 of Fig. 8 or step S18 of Fig. 10. Therefore, the substrate W processed by the particle removal unit 5 is the substrate W (Fig. 5(a) or Fig. 7(a)) in a state in which the processing liquid 251 (rinsing liquid) of the suspension 25 has been removed and particles 252 (polystyrene) have accumulated.

As shown in FIG. 13, the particle removal unit 5 includes an ultraviolet irradiation section 3C, a substrate holding section 5C, a storage section 7C, a plurality of gas supply sections 10C, an exhaust section 11C, a moving mechanism 13C, and a rotation mechanism 15C.

The substrate holding unit 5C holds the substrate W. Specifically, the substrate holding unit 5C rotates the substrate W around the rotation axis Ab of the substrate holding unit 5C while holding the substrate W horizontally. The rotation axis Ab is approximately parallel to the vertical direction and passes through the center of the substrate W. More specifically, the substrate holding unit 5C includes a spin base 51C and multiple chuck members 53C. The multiple chuck members 53C hold the substrate W in a horizontal position. The spin base 51C is approximately disk-shaped or approximately cylindrical, and supports the multiple chuck members 53C in a horizontal position.

The moving mechanism 13C moves the substrate holding part 5C in the vertical direction. Specifically, the moving mechanism 13C moves the substrate holding part 5C back and forth between a first position and a second position. The first position indicates a position where the substrate holding part 5C is close to the ultraviolet irradiation part 3C. FIG. 13 illustrates the substrate holding part 5C located at the first position. The second position indicates a position where the substrate holding part 5C is far from the ultraviolet irradiation part 3C. The first position is the position of the substrate holding part 5C when processing the substrate W using ultraviolet rays is performed. The second position is the position of the substrate holding part 5C when transferring the substrate W. The moving mechanism 13C includes, for example, a ball screw mechanism.

The rotation mechanism 15C rotates the substrate holder 5C around the rotation axis Ab. As a result, the substrate W held by the substrate holder 5C rotates around the rotation axis Ab. The rotation mechanism 15C includes, for example, a motor.

The ultraviolet irradiator 3C and the substrate holder 5C are disposed along the rotation axis Ab and face each other. The ultraviolet irradiator 3C faces the substrate W across a space SPA. The ultraviolet irradiator 3C generates ultraviolet light. The ultraviolet irradiator 3C irradiates the upper surface of the substrate W with ultraviolet light. For example, the ultraviolet irradiator 3C irradiates the upper surface of the substrate W with ultraviolet light while the substrate W is rotating. As a result, the particles 252 (polystyrene) deposited between the structures 23 of the substrate W are oxidized and decomposed by the ultraviolet light and are removed from between the structures 23 (FIGS. 5(b), 5(c), 7(b), 7(c)).

Specifically, the ultraviolet irradiation unit 3C includes an electrode 33C, an electrode 35C, and a quartz glass plate 31C. The electrode 33C has a generally flat plate shape. The electrode 35C has a generally flat plate shape. The electrode 35C also has a plurality of openings 351C. The electrode 35C faces the electrode 33C across a space. The electrode 35C is located on the quartz glass plate 31C side of the electrode 33C. The quartz glass plate 31C is provided on the substrate W side.

Discharge gas is present in the space between electrodes 33C and 35C. A high-frequency high voltage is applied between electrodes 33C and 35C. As a result, the discharge gas is excited into an excimer state. The discharge gas generates ultraviolet light when returning from the excimer state to the ground state. The ultraviolet light passes through opening 351C of electrode 35C, and then passes through quartz glass plate 31C to be irradiated onto substrate W.

The accommodation unit 7C accommodates the substrate holding unit 5C, the moving mechanism 13C, and the rotating mechanism 15C. The ultraviolet irradiation unit 3C closes the upper opening of the accommodation unit 7C. Therefore, the ultraviolet irradiation unit 3C and the accommodation unit 7C function as a chamber.

Each of the gas supply units 10C supplies an inert gas to the space SPA through a through hole 71C. The inert gas is, for example, nitrogen or argon. The exhaust unit 11C exhausts the gas inside the storage unit 7C through a through hole 73C.

The above describes the embodiments of the present invention with reference to the drawings. However, the present invention is not limited to the above embodiments, and can be implemented in various aspects without departing from the gist of the present invention. In addition, the components disclosed in the above embodiments can be modified as appropriate. For example, a component among all the components shown in one embodiment may be added to a component of another embodiment, or some of all the components shown in one embodiment may be deleted from the embodiment.

In addition, the drawings mainly show each component in a schematic manner in order to facilitate understanding of the invention, and the thickness, length, number, spacing, etc. of each component shown in the drawings may differ from the actual ones due to the convenience of creating the drawings. Furthermore, the configuration of each component shown in the above embodiment is one example and is not particularly limited, and it goes without saying that various modifications are possible within a range that does not substantially deviate from the effects of the present invention.

The present invention relates to a substrate processing method and a substrate processing apparatus, and has industrial applicability.

5 Particle removal unit 12 Spin chuck (substrate holder)
13 Spin motor (substrate rotation part)
14 Chemical nozzle (chemical supply unit)
17 Suspension nozzle (suspension supply unit)
21 Control unit 31 Rinse liquid nozzle (rinse liquid supply unit)
34 Substrate heating unit 100 Substrate processing apparatus W Substrate

Claims (26)

A substrate processing method for processing a substrate having a pattern including a plurality of structures, comprising:
a suspension supplying step of supplying a suspension, which is a mixture of a treatment liquid and a plurality of particles that are not dissolved in the treatment liquid, onto an upper surface of the substrate to form a liquid film of the suspension on the upper surface of the substrate;
a processing liquid removal step of removing the processing liquid from the upper surface of the substrate so that the particles are deposited between the structures adjacent to each other. The substrate processing method according to claim 1 , further comprising a particle removing step of removing the particles deposited between the structures by a non-liquid. A substrate processing method for processing a substrate having a pattern including a plurality of structures, comprising:
a suspension supplying step of supplying a suspension, which is a mixture of a treatment liquid and a plurality of particles that are not dissolved in the treatment liquid, onto an upper surface of the substrate to form a liquid film of the suspension on the upper surface of the substrate;
a processing liquid removal step of removing the processing liquid from the upper surface of the substrate such that the particles remain between the adjacent structures and support the structures;
A method for processing a substrate, comprising: The particles are inorganic,
the non-liquid is a vapor of a chemical liquid;
The substrate processing method according to claim 2 , wherein in the particle removing step, the particles are removed from between the structures by supplying vapor of the chemical liquid to the upper surface of the substrate. The substrate processing method according to claim 1 , wherein the particles are silica. the particles are organic;
the non-liquid is ultraviolet light or ozone;
3. The substrate processing method according to claim 2, wherein in the particle removal step, the particles are removed from between the structures by supplying the ozone to an upper surface of the substrate or by irradiating the ultraviolet light to the upper surface of the substrate. The method of claim 6 , wherein the particles are polystyrene. The substrate processing method according to claim 1 , wherein the processing liquid is a rinse liquid. The substrate processing method according to claim 1 , wherein a size of the particles is smaller than a distance between the adjacent structures. 10. The substrate processing method according to claim 1 , wherein in the process of removing the processing liquid, the processing liquid is removed from the substrate by rotating the substrate. The execution time of the processing liquid removal step is longer than the execution time of the predetermined step,
11. The substrate processing method according to claim 10 , wherein the predetermined step is a step of shaking off a processing liquid, which is the same as the processing liquid and does not contain the particles, from the substrate by rotation. The substrate processing method according to claim 2, further comprising a substrate heating step of heating the substrate after the processing liquid removal step and before the particle removal step. a chemical supplying step of supplying a chemical onto the upper surface of the substrate before the suspension supplying step;
a rinsing liquid supplying step of supplying a rinsing liquid to the upper surface of the substrate subsequent to the chemical liquid supplying step, thereby rinsing away the chemical liquid;
The substrate processing method according to claim 1 , wherein the suspension supplying step is performed subsequent to the rinsing liquid supplying step. A substrate processing apparatus for processing a substrate having a pattern including a plurality of structures,
a suspension supply unit that supplies a suspension, which is a mixture of a treatment liquid and a plurality of particles that are not dissolved in the treatment liquid, to an upper surface of the substrate to form a liquid film of the suspension on the upper surface of the substrate;
A control unit that executes processing liquid removal control;
Equipped with
The processing liquid removal control refers to control for removing the processing liquid from the upper surface of the substrate while depositing the particles between the structures adjacent to each other. The substrate processing apparatus according to claim 14 , further comprising a particle removal unit that removes the particles deposited between the structures by a non-liquid. A substrate processing apparatus for processing a substrate having a pattern including a plurality of structures,
a suspension supply unit that supplies a suspension, which is a mixture of a treatment liquid and a plurality of particles that are not dissolved in the treatment liquid, to an upper surface of the substrate to form a liquid film of the suspension on the upper surface of the substrate;
A control unit that executes processing liquid removal control;
Equipped with
The processing liquid removal control refers to control for removing the processing liquid from the upper surface of the substrate while leaving the particles between adjacent structures and supporting the structures with the particles. The particles are inorganic,
the non-liquid is a vapor of a chemical liquid;
The substrate processing apparatus according to claim 15 , wherein the particle removal unit removes the particles from between the structures by supplying vapor of the chemical liquid to an upper surface of the substrate. The substrate processing apparatus according to claim 14 , wherein the particles are silica. the particles are organic;
the non-liquid is ultraviolet light or ozone;
The substrate processing apparatus according to claim 15 , wherein the particle removal unit removes the particles from between the structures by supplying the ozone to an upper surface of the substrate or irradiating the ultraviolet light to the upper surface of the substrate. The substrate processing apparatus of claim 19 , wherein the particles are polystyrene. The substrate processing apparatus according to claim 14 , wherein the processing liquid is a rinse liquid. The substrate processing apparatus according to claim 14 , wherein a size of the particles is smaller than a distance between the adjacent structures. A substrate holder for holding the substrate;
a substrate rotation unit that rotates the substrate by rotating the substrate holding unit,
The substrate processing apparatus according to claim 14 , wherein the processing liquid removal control refers to control for rotating the substrate by the substrate rotating section. The execution time of the processing liquid removal control is longer than the execution time of the predetermined process,
24. The substrate processing apparatus according to claim 23 , wherein the predetermined step is a step of shaking off a processing liquid, which is the same as the processing liquid and does not contain the particles, from the substrate by rotation. The substrate processing apparatus according to claim 15 , further comprising a substrate heating section that heats the substrate after the processing liquid removal control is performed and before the particle removal process is performed by the particle removing unit. a chemical supply unit that supplies a chemical liquid to an upper surface of the substrate before the suspension supply unit supplies the suspension;
a rinse liquid supply unit that supplies a rinse liquid to the upper surface of the substrate subsequent to the supplying process of the chemical liquid by the chemical liquid supply unit to wash away the chemical liquid,
26. The substrate processing apparatus according to claim 14 , wherein the suspension supplying section supplies the suspension to the upper surface of the substrate after the rinsing liquid supplying section supplies the rinsing liquid.

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