JP2021073736A - Method and device for processing substrate - Google Patents

Abstract

To provide a substrate processing method and a substrate processing device capable of drying an upper surface of a substrate while effectively suppressing collapse of a pattern.SOLUTION: A substrate processing device 1 includes an organic solvent/hydrofluoric acid mixture supply unit 10 for supplying a surface of a substrate W held horizontally by a spin chuck 5 with steam containing hydrogen fluoride. The substrate processing device 1 performs foreign matters removing step for exposing foreign matters that adhere structures 61 that are about to fall and adjoin mutually to steam containing hydrogen fluoride and removes the foreign matters from the structure 61 by supplying the surface of the substrate W with the steam containing the hydrogen fluoride. In the foreign matters removing step, the foreign matters are removed from the structures 61, thereby the structures 61 that have fallen are elastically restored to an upright state.SELECTED DRAWING: Figure 2

Description

The present invention relates to a substrate processing method and a substrate processing apparatus. The substrates to be processed include, for example, semiconductor wafers, liquid crystal display substrate, plasma display substrate, FED (Field Emission Display) substrate, optical disk substrate, magnetic disk substrate, optical magnetic disk substrate, and photomask. Substrates, ceramic substrates, solar cell substrates, etc. are included.

In the manufacturing process of a semiconductor device, the surface of a substrate such as a semiconductor wafer is treated with a treatment liquid. The single-wafer type substrate processing apparatus that processes substrates one by one supplies a processing liquid to a spin chuck that rotates the substrate and a surface of the substrate that is rotated by the spin chuck while holding the substrate almost horizontally. Equipped with a nozzle for.
In a typical substrate processing step, a chemical solution is supplied to a substrate held by a spin chuck. Water is then supplied to the substrate, which replaces the chemical solution on the substrate with water. After that, a spin-drying step is performed to remove the water on the substrate. In the spin-drying process, the substrate is rotated at high speed, so that the water adhering to the substrate is shaken off and removed (dried). Common water is deionized water.

When a fine pattern is formed on the surface of the substrate, the spin-drying step may not be able to remove the water that has entered the inside of the pattern, which may lead to poor drying. Therefore, an organic solvent such as isopropyl alcohol (IPA) is supplied to the surface of the substrate after treatment with water, and the water that has entered the gaps in the pattern on the surface of the substrate is replaced with the organic solvent. A method of drying the surface has been proposed.

As shown in FIG. 20, in the spin-drying step of drying the substrate by high-speed rotation of the substrate, a liquid surface (interface between air and liquid) is formed in the pattern. In this case, the surface tension of the liquid acts at the contact position between the liquid surface and the pattern. This surface tension is one of the causes of collapsing the pattern.
When the liquid of the organic solvent (hereinafter, simply referred to as “organic solvent”) is supplied to the surface of the substrate after the rinsing treatment and before the spin-drying step as in Patent Document 1 below, the organic solvent gets into the pattern. .. The surface tension of organic solvents is lower than that of typical water. Therefore, the problem of pattern collapse due to surface tension is alleviated.

Japanese Unexamined Patent Publication No. 9-38595

However, in recent years, in order to increase the integration of devices (for example, semiconductor devices) manufactured by using substrate processing, fine and high aspect ratio patterns (convex pattern, line pattern, etc.) have been formed on the surface of the substrate. It has come to be formed. Since the fine and high aspect ratio pattern has low strength, it may collapse due to the surface tension acting on the liquid surface of the organic solvent.
Therefore, an object of the present invention is to provide a substrate processing method and a substrate processing apparatus capable of drying the upper surface of a substrate while effectively suppressing the collapse of a pattern.

The present invention comprises a substrate holding step of holding a substrate horizontally, a liquid film forming step of supplying a treatment liquid to the upper surface of the substrate to form a liquid film of the treatment liquid covering the upper surface of the substrate, and the treatment liquid. A liquid film removing region forming step of partially removing the treatment liquid from the liquid film of the processing liquid to form a liquid film removing region in the liquid film of the treatment liquid, and expanding the liquid film removing region toward the outer periphery of the substrate. In parallel with the step of expanding the liquid film removing region and the step of expanding the liquid film removing region, the atmosphere around the boundary between the liquid film removing region and the liquid film of the treatment liquid is changed to the atmosphere of vapor containing hydrogen fluoride. Provided is a substrate processing method including a step of maintaining a hydrogen fluoride atmosphere.

At the boundary between the liquid film removing region and the liquid film of the treatment liquid (hereinafter, simply referred to as “liquid film boundary”), when the treatment liquid is removed from between adjacent patterns, the pattern may collapse. The inventor of the present application has found the following findings regarding the mechanism of such pattern collapse. That is, when the elastic pattern collapses momentarily, the elasticity of the pattern itself exerts a force to stand (recover) the collapsed pattern to some extent. However, even if the pattern actually has elasticity, the collapsed pattern does not stand up and the collapsed state of the pattern is maintained. According to the inventor of the present application, as one of the factors for maintaining the collapsed state, the tip portion of the pattern that collapses momentarily is adhered to the tip portion of the adjacent pattern via a product interposed on the upper surface of the substrate. As a result, the pattern does not stand up and its collapsed state is maintained. When a silicon substrate is used as the substrate, the silicon oxide is interposed on the upper surface (surface) of the substrate, and therefore, it is considered that the product mainly contains the silicon oxide.

According to this method, the liquid film boundary is the upper surface of the substrate W while the atmosphere around the liquid film boundary is maintained by the vapor containing hydrogen fluoride (hereinafter, may be referred to as “hydrogen fluoride vapor”). Move toward the outer circumference.
Since the liquid film boundary is maintained in the atmosphere of hydrogen fluoride vapor, hydrogen fluoride reacts with the silicon oxide deposited on the liquid film of the treatment liquid, and as shown in the formula (1), H ₂ SiF. It decomposes into _{6 and water.}
SiO ₂ + 6HF → H ₂ SiF ₆ + 2H ₂ O ・ ・ ・ (1)
Thereby, the silicon oxide precipitated in the treatment liquid does not adhere to the pattern, or the silicon oxide adhering to the pattern can be removed.

Since no silicon oxide is attached to the tip of the pattern, the momentarily collapsed pattern stands up due to the elasticity of the pattern itself. As a result, the upper surface of the substrate can be dried while effectively suppressing the collapse of the pattern.
In one embodiment of the present invention, the treatment liquid contained in the liquid film of the treatment liquid has a liquid temperature higher than room temperature in the liquid film removal region expansion step.

By hydrogen fluoride reacts with the silicon oxide, there is a risk that residues (e.g. residues of H ₂ SiF ₆₎ is generated.
According to this method, the treatment liquid contained in the liquid film of the treatment liquid has a liquid temperature higher than room temperature in the step of expanding the liquid film removal region. The melting point of H ₂ SiF ₆ is about 19 ° C., and the evaporation of the residue is promoted as the temperature of the liquid film of the treatment liquid becomes higher than room temperature. As a result, the residue can be evaporated and removed from the upper surface of the substrate.
In one embodiment of the present invention, the liquid film of the treatment liquid formed in the liquid film forming step has a normal temperature. Then, the substrate treatment method includes a heating step of heating the liquid film of the treatment liquid in parallel with the liquid film removal region expansion step.

According to this method, the liquid film of the treatment liquid is heated in parallel with the step of expanding the liquid film removing region. As a result, the treatment liquid contained in the liquid film of the treatment liquid can be provided higher than room temperature in the liquid film removal region expansion step by using a simple method.
In one embodiment of the present invention, the liquid film of the treatment liquid formed by the liquid film forming step includes a liquid film of a hydrofluoric acid-containing liquid containing hydrofluoric acid. The space above the substrate is a cutoff space cut off from the surroundings. Then, the hydrogen fluoride atmosphere maintaining step is a step in which the hydrofluoric acid contained in the liquid film of the hydrofluoric acid-containing liquid evaporates in the blocking space and the vapor containing hydrogen fluoride is supplied to the blocking space. Including.

According to this method, hydrofluoric acid contained in the liquid film of the treatment liquid evaporates in the blocking space, and vapor containing hydrogen fluoride is supplied to the blocking space. As a result, a method of moving the liquid film boundary toward the outer periphery of the substrate while maintaining the atmosphere around the liquid film boundary with vapor containing hydrogen fluoride can be realized without separately supplying a gas into the blocking space.
In one embodiment of the present invention, the liquid film of the hydrofluoric acid-containing liquid includes a liquid film of a mixed liquid of an organic solvent and hydrofluoric acid having a surface tension lower than that of water.

According to this method, the liquid film of the hydrofluoric acid-containing liquid contains a liquid film of a mixed liquid of an organic solvent and hydrofluoric acid having a surface tension lower than that of water. Since the liquid film of the hydrofluoric acid-containing liquid contains an organic solvent, the surface tension of the liquid contained in the liquid film of the hydrofluoric acid-containing liquid can be lowered, and thus the collapse of the pattern can be further suppressed.
In one embodiment of the present invention, the space above the substrate is a blocking space cut off from its surroundings. Then, in the hydrogen fluoride atmosphere holding step, the vapor containing hydrogen fluoride is supplied to the blocking space in order to maintain the atmosphere around the liquid film of the treatment liquid in the atmosphere of the vapor containing hydrogen fluoride. Includes hydrogen fluoride vapor supply process.

According to this method, steam containing hydrogen fluoride is supplied to the cut-off space cut off from the surroundings. As a result, the space can be filled with the vapor containing hydrogen fluoride, and as a result, the liquid film removing region is formed on the substrate while maintaining the atmosphere around the liquid film boundary with the atmosphere of the vapor containing hydrogen fluoride. Can be expanded toward the outer circumference of.

The liquid film of the treatment liquid may be a liquid film of an organic solvent having a surface tension lower than that of water.
In one embodiment of the present invention, the hydrogen fluoride-containing vapor supplied by the hydrogen fluoride vapor supply step includes a vapor containing an organic solvent having a surface tension lower than that of water and hydrogen fluoride.
According to this method, since the vapor containing hydrogen fluoride supplied by the hydrogen fluoride vapor supply step contains not only hydrogen fluoride but also an organic solvent, the boundary with the liquid film removing region in the liquid film of the treatment liquid. The vapor of the organic solvent can be supplied to the vicinity, whereby the collapse of the pattern at the liquid film boundary can be suppressed.

The liquid film of the treatment liquid may be a liquid film of water.
In one embodiment of the present invention, the hydrogen fluoride vapor supply step includes a step of spraying the steam containing hydrogen fluoride toward the upper surface of the substrate.
According to this method, expansion of the liquid film removing region can be promoted by blowing vapor containing hydrogen fluoride onto the liquid film removing region. Therefore, by spraying the vapor containing hydrogen fluoride toward the upper surface of the substrate, not only the vapor containing hydrogen fluoride is supplied to the blocking space blocked from the surroundings, but also the liquid film removal area is expanded. Can be promoted.

The present invention is held by a substrate holding unit that holds the substrate horizontally, a rotating unit that rotates the substrate held by the substrate holding unit around a rotation axis passing through a central portion thereof, and the substrate holding unit. A blocking space forming unit for forming a blocking space blocked from the surroundings above the substrate, and a hydrofluoric acid-containing liquid supply unit for supplying a hydrofluoric acid-containing liquid containing hydrofluoric acid to the upper surface of the substrate. And a control device for controlling the hydrofluoric acid-containing liquid supply unit, and the control device supplies the hydrofluoric acid-containing liquid to the upper surface of the substrate to cover the upper surface of the substrate with hydrofluoric acid. A liquid film forming step of forming a liquid film of the liquid and a liquid film removing region are formed in the liquid film of the hydrofluoric acid-containing liquid by partially removing the hydrofluoric acid-containing liquid from the liquid film of the hydrofluoric acid-containing liquid. In parallel with the liquid film removing region forming step, the liquid film removing region expanding step of expanding the liquid film removing region toward the outer periphery of the substrate, and the liquid film removing region expanding step, the liquid film removing region and the said A hydrofluoric acid atmosphere holding step of maintaining the atmosphere around the boundary of the hydrofluoric acid-containing liquid with the liquid film in the atmosphere of steam containing hydrogen fluoride is executed, and the hydrofluoric acid atmosphere holding step is the hydrofluoric acid-containing liquid. Provided is a substrate processing apparatus including a step of supplying hydrofluoric acid containing hydrogen fluoride to the blocking space by evaporating hydrofluoric acid contained in the liquid film of the liquid in the blocking space.

In the present invention, a substrate holding unit that holds a substrate horizontally, a rotating unit that rotates a substrate held by the substrate holding unit around a rotation axis passing through a central portion thereof, and a processing liquid on the upper surface of the substrate. A processing liquid supply unit for supplying the above, a blocking space forming unit for forming a blocking space blocked from the surroundings above the substrate held by the substrate holding unit, and a vapor in the blocking space. A hydrogen fluoride vapor supply unit for supplying vapor containing hydrogen phosphite and a control device for controlling the rotation unit, the treatment liquid supply unit, and the hydrogen fluoride steam supply unit are included, and the control device horizontally holds a substrate. A substrate holding step of holding, a liquid film forming step of supplying a treatment liquid to the upper surface of the substrate to form a liquid film of the treatment liquid covering the upper surface of the substrate, and a portion of the treatment liquid from the liquid film of the treatment liquid. A liquid film removing region forming step of forming a liquid film removing region on the liquid film of the treatment liquid, and a liquid film removing region expanding step of expanding the liquid film removing region toward the outer periphery of the substrate. In parallel with the step of expanding the liquid film removing region, a hydrogen fluoride atmosphere maintaining step of maintaining the atmosphere around the boundary between the liquid film removing region and the liquid film of the treatment liquid in the atmosphere of vapor containing hydrogen fluoride. In the hydrogen fluoride atmosphere holding step, the vapor containing hydrogen fluoride is placed in the blocking space in order to maintain the atmosphere around the liquid film of the treatment liquid in the atmosphere of the vapor containing hydrogen fluoride. Provided is a substrate processing apparatus including a hydrogen fluoride vapor supply step of supplying.

The blocking space forming unit is arranged so as to face the upper surface of the substrate held by the substrate holding unit, and includes an opposing member that forms a blocking space blocked from the surroundings with the upper surface of the substrate. You may be.
The present invention is a substrate processing method for processing a substrate having a pattern including a plurality of convex structures on its surface, and a foreign substance that adheres to each other adjacent structures that have fallen down is a steam containing hydrogen fluoride. Provided is a substrate processing method comprising a foreign matter removing step of removing a foreign matter from the structure by exposing to the structure, and elastically restoring the collapsed structure to the upright state by removing the foreign matter from the structure. ..
In one embodiment of the present invention, the substrate processing method further includes a back surface heating step of heating the back surface of the substrate in parallel with the foreign matter removing step.
The present invention includes a substrate holding unit that holds a substrate having a pattern having a pattern including a plurality of convex structures on its surface, and a steam supply unit for supplying steam containing hydrogen fluoride to the surface of the substrate. The control device includes a control device that controls the steam supply unit, and the control device supplies foreign matter that adheres to each other adjacent structures that have fallen down by supplying the steam to the surface of the substrate. Provided is a substrate processing apparatus for elastically restoring a collapsed structure to the upright state by executing a foreign matter removing step of removing the foreign matter from the structure and removing the foreign matter from the structure.

FIG. 1 is a plan view for explaining the internal layout of the substrate processing apparatus according to the first embodiment of the present invention. FIG. 2 is a schematic cross-sectional view for explaining a configuration example of a processing unit provided in the substrate processing apparatus. FIG. 3 is a block diagram for explaining the electrical configuration of the main part of the substrate processing apparatus. FIG. 4 is an enlarged cross-sectional view showing the surface of the substrate to be processed by the processing unit. FIG. 5 is a flow chart for explaining a first substrate processing example by the substrate processing apparatus. FIG. 6 is a time chart for explaining the rinsing step and the drying step included in the first substrate processing example. FIG. 7A is a schematic cross-sectional view for explaining the paddle process (T1 in FIG. 6). FIG. 7B is a schematic cross-sectional view for explaining the atmosphere forming step (T2 in FIG. 6). FIG. 7C is a schematic cross-sectional view for explaining the liquid film removing region forming step (T3 in FIG. 6). FIG. 7D is a schematic cross-sectional view for explaining the liquid film removing region expansion step (T4 in FIG. 6). FIG. 7E is a diagram showing a state following FIG. 7D in the liquid film removing region expansion step. FIG. 7F is a schematic cross-sectional view for explaining the spin-drying process (T5 of FIG. 6). FIG. 8 is an enlarged cross-sectional view showing the state of the surface of the substrate in the drying region expansion step. FIG. 9 is an enlarged cross-sectional view showing the state of the surface of the substrate in the reference form. FIG. 10 is a schematic cross-sectional view for explaining a configuration example of a processing unit provided in the substrate processing apparatus according to the second embodiment of the present invention. FIG. 11 is a block diagram for explaining the electrical configuration of the main part of the substrate processing apparatus. FIG. 12 is a time chart for explaining the rinsing step and the drying step included in the second substrate processing example executed by the substrate processing apparatus. FIG. 13A is a schematic cross-sectional view for explaining the paddle process (T11 in FIG. 12). FIG. 13B is a schematic cross-sectional view for explaining the atmosphere forming step (T12 in FIG. 12). FIG. 13C is a schematic cross-sectional view for explaining the liquid film removing region forming step (T13 in FIG. 12). FIG. 13D is a schematic cross-sectional view for explaining the liquid film removing region expansion step (T14 in FIG. 12). FIG. 13E is a diagram showing a state following FIG. 13D in the liquid film removing region expansion step. FIG. 13F is a schematic cross-sectional view for explaining the spin-drying process (T15 of FIG. 12). FIG. 14 is a schematic cross-sectional view for explaining a configuration example of a processing unit provided in the substrate processing apparatus according to the third embodiment of the present invention. FIG. 15 is a block diagram for explaining the electrical configuration of the main part of the substrate processing apparatus. FIG. 16 is a time chart for explaining a rinsing step and a drying step performed by the substrate processing apparatus. FIG. 17A is a schematic cross-sectional view for explaining the paddle process (T21 in FIG. 16). FIG. 17B is a schematic cross-sectional view for explaining the atmosphere forming step (T22 in FIG. 16). FIG. 17C is a schematic cross-sectional view for explaining the liquid film removing region forming step (T23 in FIG. 16). FIG. 17D is a schematic cross-sectional view for explaining the liquid film removing region expansion step (T24 in FIG. 16). FIG. 17E is a diagram showing a state following FIG. 17D in the liquid film removing region expansion step. FIG. 17F is a schematic cross-sectional view for explaining the spin-drying process (T25 of FIG. 16). 18A and 18B are image diagrams showing the results of the recovery test. FIG. 19 is a diagram showing a modified example of the present invention. FIG. 20 is a schematic cross-sectional view for explaining the principle of pattern collapse due to surface tension.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a schematic plan view for explaining the internal layout of the substrate processing apparatus 1 according to the first embodiment of the present invention. The substrate processing device 1 is a single-wafer type device that processes substrates W such as silicon wafers one by one. In this embodiment, the substrate W is a disc-shaped substrate. The substrate processing apparatus 1 includes a plurality of processing units 2 for processing the substrate W with a processing liquid, a load port LP on which a carrier C accommodating a plurality of substrates W processed by the processing unit 2 is placed, and a load port. It includes transfer robots IR and CR that transfer the substrate W between the LP and the processing unit 2, and a control device 3 that controls the substrate processing device 1. The transfer robot IR transfers the substrate W between the carrier C and the transfer robot CR. The transfer robot CR transfers the substrate W between the transfer robot IR and the processing unit 2. The plurality of processing units 2 have, for example, a similar configuration.

FIG. 2 is a schematic cross-sectional view for explaining a configuration example of the processing unit 2.
The processing unit 2 holds the box-shaped chamber 4 and one substrate W in the chamber 4 in a horizontal posture, and rotates the substrate W around the vertical rotation axis A1 passing through the center of the substrate W. (Substrate holding unit, rotating unit) 5, a chemical solution supply unit (treatment solution supply unit) 6 for supplying a chemical solution to the upper surface of the substrate W held by the spin chuck 5, and a spin chuck 5. A rinse solution supply unit (treatment solution supply unit) 7 for supplying a rinse solution (treatment solution) to the upper surface of the substrate W, and a hot plate (heating unit) for heating the substrate W held by the spin chuck 5 from the lower surface side. ) 8, the opposing member 9 facing the upper surface of the substrate W held by the spin chuck 5, and IPA (isopropyl alcohol) and hydrofluoric acid (hydrogen fluoride (hydrogen fluoride), which are examples of organic solvents having a surface tension lower than that of water. A mixed solution (treatment solution, hereinafter referred to as "organic solvent / hydrofluoric acid mixed solution") with (HF) solution). In FIG. 6, the IPA / HF (liquid) is placed on the substrate W held by the spin chuck 5. It includes an organic solvent / hydrofluoric acid mixed liquid supply unit (hydrofluoric acid-containing liquid supply unit) 10 for supplying, and a tubular cup (not shown) that surrounds the spin chuck 5.

The chamber 4 has a box-shaped partition wall (not shown) that houses the spin chuck 5 and the nozzle. Clean air (air filtered by a filter) is supplied into the partition wall by an FFU (fan filter unit, not shown). Further, the gas in the chamber 4 is exhausted through an exhaust duct (not shown). The processing of the substrate W is performed in a state where a downflow (downflow) flowing downward in the chamber 4 is formed in the chamber 4.

As the spin chuck 5, a holding type chuck that sandwiches the substrate W in the horizontal direction and holds the substrate W horizontally is adopted. Specifically, the spin chuck 5 includes a spin motor 13, a spin shaft 14 integrated with a drive shaft of the spin motor 13, and a disc-shaped spin base substantially horizontally attached to the upper end of the spin shaft 14. Including 15.
On the upper surface of the spin base 15, a plurality of (three or more, for example, six) holding members 16 are arranged on the peripheral edge thereof. The plurality of sandwiching members 16 are arranged on the upper peripheral edge of the spin base 15 at appropriate intervals on the circumference corresponding to the outer peripheral shape of the substrate W.

Further, the spin chuck 5 is not limited to the holding type, for example, the substrate W is held in a horizontal posture by vacuum-sucking the back surface of the substrate W, and further rotates around a vertical rotation axis in that state. By doing so, a vacuum suction type (vacuum chuck) that rotates the substrate W held by the spin chuck 5 may be adopted.
The chemical solution supply unit 6 includes a chemical solution nozzle 17, a chemical solution pipe 18 connected to the chemical solution nozzle 17, a chemical solution valve 19 interposed in the chemical solution pipe 18, and a first nozzle moving unit 20 for moving the chemical solution nozzle 17. including. The chemical solution nozzle 17 is, for example, a straight nozzle that discharges a liquid in a continuous flow state. The chemical solution from the chemical solution supply source is supplied to the chemical solution pipe 18.

When the chemical solution valve 19 is opened, the chemical solution supplied from the chemical solution pipe 18 to the chemical solution nozzle 17 is discharged downward from the chemical solution nozzle 17. When the chemical solution valve 19 is closed, the discharge of the chemical solution from the chemical solution nozzle 17 is stopped. The first nozzle moving unit 20 has a processing position where the chemical solution discharged from the chemical solution nozzle 17 is supplied to the upper surface of the substrate W and a retracted position where the chemical solution nozzle 17 is retracted to the side of the spin chuck 5 in a plan view. The chemical solution nozzle 17 is moved between them.

Specific examples of the chemical solution are an etching solution and a cleaning chemical solution. More specifically, the chemicals include sulfuric acid, acetic acid, nitric acid, hydrochloric acid, hydrofluoric acid, aqueous ammonia, hydrogen peroxide solution, organic acids (eg citric acid, oxalic acid, etc.), organic alkalis (eg, TMAH: tetramethylammonium hydro). It may be a liquid containing at least one of (oxide, etc.), a surfactant, and an antioxidant.

The rinse liquid supply unit 7 moves the rinse liquid nozzle 21, the rinse liquid pipe 22 connected to the rinse liquid nozzle 21, the rinse liquid valve 23 interposed in the rinse liquid pipe 22, and the rinse liquid nozzle 21. The nozzle moving unit 24 of 2 is included. The rinse liquid nozzle 21 is, for example, a straight nozzle that discharges liquid in a continuous flow state. The rinse liquid pipe 22 is supplied with a rinse liquid at room temperature (about 23 ° C.) from the rinse liquid supply source.

When the rinse liquid valve 23 is opened, the rinse liquid supplied from the rinse liquid pipe 22 to the rinse liquid nozzle 21 is discharged downward from the rinse liquid nozzle 21. When the rinse liquid valve 23 is closed, the discharge of the rinse liquid from the rinse liquid nozzle 21 is stopped. The second nozzle moving unit 24 has a processing position where the chemical liquid discharged from the rinsing liquid nozzle 21 is supplied to the upper surface of the substrate W and a retracting position where the rinsing liquid nozzle 21 is retracted to the side of the spin chuck 5 in a plan view. The rinse liquid nozzle 21 is moved between and.

Specific examples of the rinsing solution are, for example, deionized water (DIW), but not limited to DIW, carbonated water, electrolytic ionized water, hydrogen water, ozone water, and hydrochloric acid water having a dilution concentration (for example, about 10 ppm to 100 ppm). It may be either.
The chemical solution nozzle 17 and the rinse solution nozzle 21 do not need to be provided so as to be scannable. For example, the chemical solution nozzle 17 and the rinse solution nozzle 21 are fixedly provided above the spin chuck 5 and are provided at predetermined positions on the upper surface of the substrate W. Alternatively, a so-called fixed nozzle form in which the rinse liquid) is applied may be adopted.

The hot plate 8 has a disk shape having substantially the same diameter as the substrate W or a diameter slightly smaller than that of the substrate W, and is in a horizontal posture. The hot plate 8 is arranged between the upper surface of the spin base 15 and the lower surface of the substrate W held by the spin chuck 5. The hot plate 8 is configured by embedding a heater 8a inside, for example, a ceramic plate body. The heat generated by the heater 8a warms the upper surface of the hot plate 8. The hot plate 8 is supported from below by the vertical support rod 25. The support rod 25 is inserted into the spin base 15 and the spin shaft 14. The support rod 25 is in non-contact with the spin base 15 and the spin shaft 14. The support rod 25 is provided so as to be non-rotatable and movable with respect to the chamber 4. That is, even if the spin chuck 5 rotates, the hot plate 8 does not rotate. Therefore, when the spin chuck 5 rotates the substrate W, the substrate W and the hot plate 8 rotate relative to each other around the rotation axis A1.

A hot plate elevating unit 26 for elevating and elevating the hot plate 8 in a horizontal posture is connected to the support rod 25. By driving the hot plate elevating unit 26, the hot plate 8 is provided at an upper position where the upper surface thereof is close to the upper surface of the spin base 15 at a predetermined minute interval and below the upper position, and is provided from the hot plate 8. It is provided so as to be able to move up and down from a lower position where radiant heat hardly reaches the lower surface of the substrate W. By raising and lowering the hot plate 8, the distance between the hot plate 8 and the substrate W is changed.

The facing member 9 includes a blocking plate 27, an upper spin shaft 28 rotatably provided on the blocking plate 27, and an upper nozzle 29 penetrating the central portion of the blocking plate 27 in the vertical direction. The blocking plate 27 includes a horizontally arranged disc portion 30 and a tubular portion 31 provided along the outer peripheral edge of the disc portion 30. The disk portion 30 has a disk shape having a diameter substantially the same as or larger than that of the substrate W. The disk portion 30 has a circular substrate facing surface 43 facing the entire upper surface of the substrate W on its lower surface. A cylindrical through hole 44 that vertically penetrates the disk portion 30 is formed in the central portion of the substrate facing surface 43. The through hole 44 is partitioned by a cylindrical inner peripheral surface.

The tubular portion 31 may have a truncated cone shape. As shown in FIG. 2, the tubular portion 31 may extend downward so as to extend outward from the outer peripheral edge of the disc portion 30. Further, as shown in FIG. 2, the thickness of the tubular portion 31 may decrease as it approaches the lower end of the tubular portion 31.
The upper spin shaft 28 is rotatably provided around a rotation axis A2 (an axis corresponding to the rotation axis A1 of the substrate W) extending vertically through the center of the blocking plate 27. The upper spin shaft 28 has a cylindrical shape. The inner peripheral surface of the upper spin shaft 28 is formed as a cylindrical surface centered on the rotation axis A2. The internal space of the upper spin shaft 28 communicates with the through hole 44 of the blocking plate 27. The upper spin shaft 28 is rotatably supported by a support arm 32 extending horizontally above the blocking plate 27.

In this embodiment, the upper nozzle 29 functions as a central axis nozzle. The upper nozzle 29 is arranged above the spin chuck 5. The upper nozzle 29 is supported by the support arm 32. The upper nozzle 29 is non-rotatable with respect to the support arm 32. The upper nozzle 29 moves up and down together with the blocking plate 27, the upper spin shaft 28, and the support arm 32. The upper nozzle 29 forms a central discharge port 33 at the lower end thereof, which faces the central portion of the upper surface of the substrate W held by the spin chuck 5. The central discharge port 33 is arranged at substantially the same height as the substrate facing surface 43 of the blocking plate 27 or above the substrate facing surface 43. A cylindrical tubular gap 34 is formed between the upper nozzle 29, the blocking plate 27, and the upper spin shaft 28, and the tubular gap 34 is a flow path through which an inert gas such as nitrogen gas flows. Is functioning as. The lower end of the tubular gap 34 opens in an annular shape surrounding the upper nozzle 29 to form a peripheral discharge port 35.

A blocking plate rotating unit 36 having a configuration including an electric motor and the like is coupled to the blocking plate 27. The blocking plate rotating unit 36 rotates the blocking plate 27 and the upper spin shaft 28 around the rotation axis A2 with respect to the support arm 32.
Further, the support arm 32 is coupled with an opposing member elevating unit 37 having a configuration including an electric motor, a ball screw, and the like. The facing member elevating unit 37 raises and lowers the facing member 9 (blocking plate 27 and the upper spin shaft 28) and the upper nozzle 29 in the vertical direction together with the support arm 32.

In the facing member evacuation unit 37, the blocking plate 27 is close to the upper surface of the substrate W whose substrate facing surface 43 is held by the spin chuck 5, and the height of the lower end of the tubular portion 31 is lower than the height of the substrate W. It is moved up and down between a blocking position (see FIG. 7B, etc.) located at the position of 1 and a retracting position (see FIG. 2) retracted above the blocking position. The facing member elevating unit 37 can hold the blocking plate 27 at, for example, three positions (blocking position, proximity position, and retracting position). The blocking position is such that the substrate facing surface 43 forms a blocking space 38 (see FIG. 7B or the like) between the substrate facing surface 43 and the upper surface of the substrate W. Although the blocking space 38 is not completely isolated from the surrounding space, there is no inflow of gas from the surrounding space into the blocking space 38. That is, the cutoff space 38 is substantially cut off from the space around it. In this embodiment, the facing member 9 and the facing member elevating unit 37 form a blocking space forming unit for forming the blocking space 38.

The organic solvent / hydrofluoric acid mixed solution supply unit 10 supplies the organic solvent / hydrofluoric acid mixed solution to the upper nozzle 29. The organic solvent / hydrofluoric acid mixed liquid supply unit 10 was connected to the organic solvent liquid pipe 39 connected to the upper nozzle 29, the organic solvent liquid valve 40 interposed in the organic solvent liquid pipe 39, and the upper nozzle 29. The hydrofluoric acid pipe 41 and the hydrofluoric acid valve 42 interposed in the hydrofluoric acid pipe 41 are included. By opening the organic solvent liquid valve 40 and the hydrofluoric acid valve 42 at the same time, for example, the organic solvent liquid at room temperature and the hydrofluoric acid are supplied to the upper nozzle 29, whereby the organic solvent / hydrofluoric acid mixed liquid is supplied to the central portion. It is discharged downward from the discharge port 33.

FIG. 3 is a block diagram for explaining the electrical configuration of the main part of the substrate processing apparatus 1.
The control device 3 is configured by using, for example, a microcomputer. The control device 3 has an arithmetic unit such as a CPU, a fixed memory device, a storage unit such as a hard disk drive, and an input / output unit. The storage unit stores the program executed by the arithmetic unit.

Further, the control device 3 includes a spin motor 13, an opposing member elevating unit 37, a blocking plate rotating unit 36, a first nozzle moving unit 20, a second nozzle moving unit 24, a heater 8a, and the like according to a predetermined program. Control the operation. Further, the control device 3 opens and closes the chemical liquid valve 19, the rinse liquid valve 23, the organic solvent liquid valve 40, the hydrofluoric acid valve 42, and the like according to a predetermined program.

FIG. 4 is an enlarged cross-sectional view showing the surface of the substrate W to be processed by the processing unit 2. The substrate W to be processed is, for example, a silicon wafer, and the pattern P is formed on the surface (upper surface 62) which is the pattern forming surface thereof. The pattern P is, for example, a fine pattern. As shown in FIG. 4, the pattern P may be a structure in which structures 61 having a convex shape (columnar shape) are arranged in a matrix. In this case, the line width W1 of the structure 61 is provided, for example, about 10 nm to 45 nm, and the gap W2 of the pattern P is provided, for example, about 10 nm to several μm. The film thickness T of the pattern P is, for example, about 1 μm. Further, in the pattern P, for example, the aspect ratio (ratio of the film thickness T to the line width W1) may be, for example, about 5 to 500 (typically, about 5 to 50).

Further, the pattern P may be a pattern in which line-shaped patterns formed by fine trenches are repeatedly arranged. Further, the pattern P may be formed by providing a plurality of micropores (voids or pores) in the thin film.
The pattern P includes, for example, an insulating film. Further, the pattern P may include a conductor film. More specifically, the pattern P is formed by a laminated film in which a plurality of films are laminated, and may further include an insulating film and a conductor film. The pattern P may be a pattern composed of a monolayer film. The insulating film may be a silicon oxide film (SiO ₂ film) or a silicon nitride film (SiN film). Further, the conductor film may be an amorphous silicon film into which impurities for lowering the resistance are introduced, or may be a metal film (for example, a metal wiring film).

Further, the pattern P may be a hydrophilic film. As the hydrophilic film, a TEOS film (a type of silicon oxide film) can be exemplified.
FIG. 5 is a flow chart for explaining a first substrate processing example by the substrate processing apparatus 1. FIG. 6 is a time chart for explaining a rinsing step (S3 in FIG. 5) and a drying step (S4 in FIG. 5) included in the first substrate processing example. 7A-7F are schematic diagrams for explaining the drying step (S4 in FIG. 5). FIG. 8 is an enlarged cross-sectional view showing the state of the surface of the substrate W in the liquid film removing region expansion step T14.

A first substrate processing example will be described with reference to FIGS. 1 to 6. 7A to 8 will be referred to as appropriate.
The untreated substrate W (for example, a circular substrate having a diameter of 450 mm) is carried into the processing unit 2 from the carrier C by the transfer robots IR and CR, and is carried into the chamber 4, and the substrate W moves upward on its surface (pattern forming surface). The substrate W is delivered to the spin chuck 5 in a state of being directed toward the spin chuck 5, and the substrate W is held by the spin chuck 5 (S1: substrate carry-in (substrate holding step) in FIG. Prior to carrying in the substrate W, the chemical solution nozzle 17 and the rinse solution nozzle 21 are retracted to the home position set on the side of the spin chuck 5. Further, the blocking plate 27 is also retracted to the retracted position.

After the transfer robot CR has retracted to the outside of the processing unit 2, the control device 3 executes the chemical solution step (step S2 in FIG. 5). Specifically, the control device 3 controls the spin motor 13 to rotate the spin base 15 at a predetermined liquid processing speed (for example, about 800 rpm). Further, the control device 3 moves the chemical solution nozzle 17 from the retracted position to the processing position by controlling the first nozzle moving unit 20. After that, the control device 3 opens the chemical solution valve 19 and discharges the chemical solution from the chemical solution nozzle 17 toward the upper surface of the rotating substrate W. The chemical solution discharged from the chemical solution nozzle 17 is supplied to the upper surface of the substrate W and then flows outward along the upper surface of the substrate W by centrifugal force. Further, the control device 3 moves the supply position of the chemical solution with respect to the upper surface of the substrate W between the central portion and the peripheral portion while the substrate W is rotating. As a result, the supply position of the chemical solution passes through the entire upper surface of the substrate W, the entire upper surface of the substrate W is scanned, and the entire upper surface of the substrate W is uniformly processed. When a predetermined period elapses from the start of ejection of the chemical solution, the control device 3 closes the chemical solution valve 19 to stop the discharge of the chemical solution from the chemical solution nozzle 17, and then controls the first nozzle moving unit 20. , The chemical solution nozzle 17 is retracted from above the spin chuck 5.

Next, the control device 3 executes a rinsing step (step S3 in FIG. 5). The rinsing step is a step of replacing the chemical solution on the substrate W with the rinse solution and removing the chemical solution from the substrate W. Specifically, the control device 3 moves the rinse liquid nozzle 21 from the retracted position to the processing position by controlling the second nozzle moving unit 24. After that, the control device 3 opens the rinse liquid valve 23 and discharges the rinse liquid from the rinse liquid nozzle 21 toward the upper surface of the rotating substrate W. The rinse liquid discharged from the rinse liquid nozzle 21 is supplied to the upper surface of the substrate W and then flows outward along the upper surface of the substrate W by centrifugal force. Further, the control device 3 moves the supply position of the rinse liquid with respect to the upper surface of the substrate W between the central portion and the peripheral portion while the substrate W is rotating. As a result, the rinse liquid supply position passes over the entire upper surface of the substrate W, the entire upper surface of the substrate W is scanned, and the entire upper surface of the substrate W is uniformly processed. When a predetermined period has elapsed from the start of discharging the rinse liquid, the control device 3 closes the rinse liquid valve 23 to stop the discharge of the rinse liquid from the rinse liquid nozzle 21, and then causes the second nozzle moving unit 24 to move. By controlling, the rinse liquid nozzle 21 is retracted from above the spin chuck 5.

After a predetermined period has elapsed from the start of supply of the rinse liquid, the control device 3 controls the spin motor 13 to process the rotation speed of the substrate W with the liquid in a state where the entire upper surface of the substrate W is covered with the rinse liquid. The speed is gradually reduced from the speed to the paddle speed (zero or a low rotation speed of about 40 rpm or less. In the first substrate processing example, for example, about 10 rpm). After that, the rotation speed of the substrate W is maintained at the paddle speed (paddle rinse step T41 (liquid film forming step)). As a result, a liquid film of the rinse liquid covering the entire upper surface of the substrate W is supported on the upper surface of the substrate W in a paddle shape. In this state, the centrifugal force acting on the liquid film of the rinse liquid on the upper surface of the substrate W is smaller than the surface tension acting between the rinse liquid and the upper surface of the substrate W, or the centrifugal force and the surface tension mentioned above. Are almost in competition with each other. Due to the deceleration of the substrate W, the centrifugal force acting on the rinse liquid on the substrate W weakens, and the amount of the rinse liquid discharged from the substrate W decreases.

When a predetermined period elapses after decelerating the substrate W to the paddle speed, the control device 3 closes the rinse liquid valve 23 and stops the discharge of the rinse liquid from the rinse liquid nozzle 21. After that, the control device 3 controls the second nozzle moving unit 24 to return the rinse liquid nozzle 21 to the retracted position.
When a predetermined period elapses after decelerating the substrate W to the paddle speed, the paddle rinsing step T41 is completed (the rinsing step (S3 in FIG. 5) is completed), and the execution of the drying step (step S4) is started. .. The drying step (step S4) includes a paddle step T1 (see FIG. 6) in which a liquid film of an organic solvent / hydrofluoric acid mixed liquid (liquid film of a hydrofluoric acid-containing liquid) 51 is held on the upper surface of the substrate W, and a blocking space 38. In the atmosphere forming step T2 (see FIG. 6), which fills (forms) an atmosphere containing a large amount of hydrogen fluoride vapor (HF vapor), and the organic solvent / hydrofluoric acid from the liquid film 51 of the organic solvent / hydrofluoric acid mixed solution. A liquid film removing region forming step T3 (see FIG. 6) in which the mixed liquid is partially eliminated to form a circular liquid film removing region 52 in the central portion of the liquid film 51 of the organic solvent / hydrofluoric acid mixed liquid, and the liquid. A liquid film removing area expanding step T4 (see FIG. 6) that expands the film removing area 52 toward the outer periphery of the substrate W, and a spin drying step T5 (see FIG. 6) in which the substrate W is shaken off and rotated at a drying rate to dry the upper surface of the substrate W. (See FIG. 6). After the drying step (S4 in FIG. 5) is completed, the transfer robot CR enters the processing unit 2 and carries out the processed substrate W to the outside of the processing unit 2 (step S5 in FIG. 5). The substrate W is passed from the transfer robot CR to the transfer robot IR, and is housed in the carrier C by the transfer robot IR.

The drying step (S4 in FIG. 5) will be described in detail.
Prior to the start of the paddle step T1, the control device 3 controls the opposing member elevating unit 37 to lower the blocking plate 27 from the retracted position to the close position. After the cutoff plate 27 is arranged at a close position, the control device 3 opens the organic solvent liquid valve 40 and the hydrofluoric acid valve 42 while keeping the rotation of the substrate W at the paddle speed, and opens the central discharge port of the cutoff plate 27. The organic solvent / hydrofluoric acid mixed solution is discharged from 33. As a result, the rinsing liquid contained in the liquid film on the upper surface of the substrate W is sequentially replaced with the organic solvent / hydrofluoric acid mixed liquid. As a result, as shown in FIG. 7A, a liquid film 51 of the organic solvent / hydrofluoric acid mixed solution covering the entire upper surface of the substrate W is held in a paddle shape on the upper surface of the substrate W (paddle step T1). The thickness of the bulk portion 54 (see FIG. 8) of the liquid film 51 of the organic solvent / hydrofluoric acid mixed solution is larger than the height of the pattern P. When almost all the liquid film over the entire upper surface of the substrate W is replaced with the liquid film 51 of the organic solvent / hydrofluoric acid mixed solution, the control device 3 closes the organic solvent liquid valve 40 and the hydrofluoric acid valve 42 and discharges the central portion. The discharge of the organic solvent / hydrofluoric acid mixed solution from the outlet 33 is stopped. As a result, the paddle step T1 is completed.

When a silicon substrate is used as the substrate W, silicon oxide may be deposited on the liquid film 51 of the organic solvent / hydrofluoric acid mixed solution. This silicon oxide was produced in the chemical solution step (S2 in FIG. 5) for the substrate W, and remained on the substrate W until the drying step (S4 in FIG. 5).
After the discharge of the organic solvent / hydrofluoric acid mixed solution is stopped, the control device 3 controls the facing member elevating unit 37 to lower the blocking plate 27 from the close position to the blocking position. As a result, a blocking space 38 (see FIG. 7B) is formed between the substrate facing surface 43 and the upper surface of the substrate W.

Further, after the discharge of the organic solvent / hydrofluoric acid mixed solution is stopped, the control device 3 controls the heater 8a to generate heat of the hot plate 8. As a result, the substrate W is heated from the lower surface side, and the temperature of the liquid film 51 of the organic solvent / hydrofluoric acid mixed solution on the substrate W is raised. By this heating, the liquid film 51 of the organic solvent / hydrofluoric acid mixed solution on the substrate W _{is higher than the melting point of H 2} SiF ₆ (about 19 ° C.) and the boiling point of IPA (about 82.4). It is warmed to a predetermined temperature (° C) lower than (° C). By raising the temperature of the organic solvent liquid contained in the liquid film 51 of the organic solvent / hydrofluoric acid mixture, the performance of replacing the rinse liquid with the organic solvent can be improved.

Then, the control device 3 rotates the substrate W at a paddle speed while the supply of the processing liquid and the processing gas to the substrate W are stopped (the discharge of the inert gas from the ambient discharge port 35 is also stopped). By raising the temperature of the liquid film 51 of the organic solvent / hydrofluoric acid mixed solution, the hydrofluoric acid contained in the liquid film 51 of the organic solvent / hydrofluoric acid mixed solution is evaporated. Hydrogen fluoride vapor (hereinafter referred to as "hydrogen fluoride vapor") generated by this evaporation is supplied to the blocking space 38. Since hydrofluoric acid has a boiling point of about 19 ° C., it boils even at room temperature (for example, about 23 ° C.), but by raising the temperature of the liquid film 51 of the organic solvent / hydrofluoric acid mixed solution to about 70 to 80 ° C. The evaporation of hydrofluoric acid can be further promoted. As a result, as shown in FIG. 7B, the atmosphere of the blocking space 38 is filled with hydrogen fluoride vapor (HF vapor) (atmosphere forming step T2).

When a predetermined period elapses from the end of the paddle step T1, the control device 3 controls the spin motor 13 to accelerate the rotation speed of the substrate W. Specifically, the control device 3 gradually increases the rotation speed of the substrate W toward the first rotation speed (for example, about 50 rpm). As the rotation speed of the substrate W increases, the centrifugal force due to the rotation of the substrate W increases, which spreads the organic solvent / hydrofluoric acid mixed solution in the central portion of the substrate W outward. As a result, as shown in FIG. 7C, the liquid film 51 of the organic solvent / hydrofluoric acid mixed solution is partially removed in the central portion of the substrate W, and as a result, the small-diameter circular liquid film is removed in the central portion of the substrate W. The region 52 is formed (liquid film removal region forming step T3). The formation of the liquid film removing region 52 is performed in a state where the blocking space 38 is filled with hydrogen fluoride vapor (HF vapor). That is, the atmosphere around the boundary 53 (hereinafter referred to as “liquid film boundary 53”) with the liquid film removing region 52 in the liquid film 51 of the organic solvent / hydrofluoric acid mixed solution becomes the atmosphere of hydrogen fluoride vapor (HF vapor). Be kept.

After forming the liquid film removing region 52, the control device 3 controls the spin motor 13 to maintain the rotation speed of the substrate W at the first rotation speed (for example, about 50 rpm). As a result, the liquid film removing region 52 slowly expands (liquid film removing region expanding step T4). As the liquid film removing region 52 expands, the liquid film boundary 53 moves outward in the radial direction, as shown in FIG. 7D. As shown in FIG. 7E, in the liquid film removing region expansion step T4, the liquid film removing region 52 is expanded over the entire upper surface of the substrate W. That is, the liquid film boundary 53 also moves to the upper peripheral edge of the substrate W. The expansion of the liquid film removing region 52 is also performed in a state where the blocking space 38 is filled with hydrogen fluoride vapor (HF vapor) (hydrogen fluoride atmosphere holding step). That is, the liquid film boundary 53 moves from the central portion of the substrate W to the upper peripheral edge of the substrate W while the atmosphere around the liquid film boundary 53 is maintained by hydrogen fluoride vapor (HF vapor).

As shown in FIG. 8, as the liquid film boundary 53 moves, an organic solvent / hydrofluoric acid mixed liquid (substantially an organic solvent liquid due to the evaporation of hydrofluoric acid) is formed between the patterns P on the surface of the substrate W. It is sequentially removed from the central portion of the substrate W toward the upper peripheral edge of the substrate W. There is a difference in surface tension acting on the pattern P through which the liquid film boundary 53 passes, which causes the pattern P to momentarily collapse toward the bulk portion 54 side (that is, the outer side of the substrate W). The organic solvent liquid (IPA liquid) has a lower surface tension than water, but since the pattern P is a fine pattern, momentary pattern collapse occurs.

FIG. 9 is an enlarged cross-sectional view showing the state of the surface of the substrate W in the reference form. This reference embodiment is different from the first substrate processing example in that in the liquid film removing region expansion step, the atmosphere around the upper surface of the substrate W is changed to dry air without providing the blocking space 38. There is.
In the case of FIG. 9, it is considered that the collapsed state of the pattern P that collapsed momentarily is maintained. That is, when the elastic pattern collapses momentarily, the elasticity of the pattern P itself exerts a force to stand (recover) the collapsed pattern P to some extent. However, the tip PA of the pattern P that collapses momentarily passes through the silicon oxide (that is, the product 55 (foreign matter)) deposited on the liquid film 51 of the organic solvent / hydrofluoric acid mixed solution. It adheres to the tip of the pattern adjacent to P and the bulk portion 54 side (that is, the outer side of the substrate W). As a result, the standing (recovery) of the pattern P is prevented, and the collapsed state of the pattern P is maintained. It is considered that pattern collapse occurs in the entire area of the substrate W by such a mechanism.

On the other hand, as shown in FIG. 8, in the first substrate treatment example, the liquid film is maintained in the atmosphere around the liquid film boundary 53 by hydrogen fluoride vapor (HF vapor, vapor containing hydrogen fluoride). The boundary 53 moves from the center of the upper surface of the substrate W to the peripheral edge of the upper surface of the substrate W. When the atmosphere around the liquid film boundary 53 is maintained by hydrogen fluoride vapor (HF vapor), it reacts with the silicon oxide precipitated on the liquid film 51 of the organic solvent / hydrofluoric acid mixed solution, and the formula (2) ), It decomposes into _{H 2} SiF _{6 and water.}
SiO ₂ + 6HF → H ₂ SiF ₆ + 2H ₂ O ・ ・ ・ (2)
Therefore, hydrogen fluoride contained in the atmosphere around the liquid film boundary 53 reacts with the silicon oxide precipitated on the liquid film 51 of the organic solvent / hydrofluoric acid mixed solution, and as a result, the organic solvent / hydrofluoric acid mixture is mixed. The silicon oxide deposited on the liquid film 51 of the liquid did not adhere to the tip Pa of the pattern P, or the silicon oxide adhered to the tip Pa of the pattern P (that is, the product 55 (see FIG. 9). )) Is also removed from the tip Pa of the pattern P (foreign matter removing step).

Further, in the liquid film removing region expansion step T4, the liquid film 51 of the organic solvent / hydrofluoric acid mixed solution is maintained at about 70 to 80 ° C. Therefore, the hydrogen fluoride contained in the hydrogen fluoride vapor (HF vapor) reacts with the silicon oxide to generate a residue of _{H 2} SiF _6. However, the silicon oxide is contained in the liquid film 51 of the organic solvent / hydrofluoric acid mixed solution, and the organic solvent / hydrofluoric acid mixed solution having a liquid temperature of about 70 to 80 ° C. (substantially due to the evaporation of the hydrofluoric acid). By contacting the liquid with an organic solvent liquid), evaporation of such a residue is promoted. Since the melting point of H ₂ SiF ₆ is about 19 ° C., in an environment of about 70 to 80 ° C., the residue of evaporation is accelerated. Thereby, the residue can be evaporated and removed from the surface of the substrate W.

Further, since the liquid temperature of the liquid film 51 of the organic solvent / hydrofluoric acid mixed liquid _{is higher than the melting point of H 2} SiF ₆ (about 19 ° C.) and lower than the boiling point of IPA (about 82.4 ° C.). while the liquid film 51 of the organic solvent / hydrofluoric acid mixture keeping the film form, it is possible to achieve removal of the residue H ₂ SiF _6.
As shown in FIG. 7F, after the liquid film removing region 52 is expanded over the entire upper surface of the substrate W, the control device 3 further accelerates the rotation of the substrate W to a shake-off drying speed (for example, about 1500 rpm). As a result, the liquid on the upper surface of the substrate W can be shaken off, whereby the upper surface of the substrate W can be completely dried.

When a predetermined period elapses from the acceleration of the rotation of the substrate W, the control device 3 controls the spin motor 13 to stop the rotation of the spin chuck 5. As a result, the drying step (S4 in FIG. 5) is completed.
After the drying step (S4 in FIG. 5) is completed, the control device 3 controls the heater 8a to stop the heat generation of the hot plate 8. Further, the control device 3 controls the opposing member elevating unit 37 to raise the blocking plate 27 from the retracted position to the close position. As a result, the blocking space 38 disappears. After that, the substrate W is carried out by the transfer robot CR.

As described above, according to this embodiment, the liquid film boundary 53 extends from the center of the upper surface of the substrate W to the upper peripheral edge of the substrate W while the atmosphere around the liquid film boundary 53 is maintained by hydrogen fluoride vapor (HF vapor). Moving. When the atmosphere around the liquid film boundary 53 is maintained by hydrogen fluoride vapor (HF vapor), the hydrogen fluoride contained in the hydrogen fluoride vapor (HF vapor) is the liquid film of the organic solvent / hydrofluoric acid mixed solution. reacts with silicon oxide which is precipitated in _51, decomposes into and water H 2 SiF _6.

As a result, the silicon oxide deposited on the liquid film 51 of the organic solvent / hydrofluoric acid mixed solution does not adhere to the tip Pa of the pattern P, or the silicon oxide adheres to the tip Pa of the pattern P ( That is, the product 55 (see FIG. 9)) is also removed from the tip Pa of the pattern P.
Further, in the liquid film removing region expansion step T4, the liquid film 51 of the organic solvent / hydrofluoric acid mixed solution is maintained at about 70 to 80 ° C. Therefore, the hydrogen fluoride contained in the hydrogen fluoride vapor (HF vapor) reacts with the silicon oxide to generate a residue of _{H 2} SiF _6. However, the silicon oxide is contained in the liquid film 51 of the organic solvent / hydrofluoric acid mixed solution, and the organic solvent / hydrofluoric acid mixed solution having a liquid temperature of about 70 to 80 ° C. (substantially due to the evaporation of the hydrofluoric acid). By contacting the liquid with an organic solvent liquid), evaporation of such a residue is promoted. Since the melting point of H ₂ SiF ₆ is about 19 ° C., in an environment of about 70 to 80 ° C., the residue of evaporation is accelerated. Thereby, the residue can be evaporated and removed from the surface of the substrate W.

As a result, at each liquid film boundary 53, even if the pattern P is momentarily collapsed, the collapsed state is not maintained, and then the pattern P itself stands up (restored) due to its elasticity. It is also one of the factors that the pattern P is restored that the collapsed shape is not memorized in the momentary collapse. Therefore, the upper surface of the substrate W can be dried while effectively suppressing the collapse of the pattern P.

FIG. 10 is a schematic cross-sectional view for explaining a configuration example of the processing unit 202 provided in the substrate processing apparatus 201 according to the second embodiment of the present invention.
In the embodiment shown in the second embodiment, the same reference numerals as those in the cases of FIGS. 1 to 8 are assigned to the parts common to the first embodiment described above, and the description thereof will be omitted.
In the treatment unit 202, instead of the organic solvent / hydrofluoric acid mixed liquid supply unit 10 (see FIG. 2), an IPA (isopropyl alcohol) liquid, which is an example of an organic solvent liquid having a surface tension lower than that of water, is applied to the spin chuck 5. An organic solvent liquid supply unit 203 for supplying on the held substrate W and a hydrogen fluoride vapor supply for supplying hydrogen fluoride vapor (HF vapor) on the substrate W held in the spin chuck 5. It differs from the processing unit 2 according to the first embodiment in that it includes the unit 204. Further, the processing unit 202 supplies hot water, which is an example of a heating fluid, to the lower surface of the substrate W held by the spin chuck 5 (the back surface opposite to the pattern forming surface) instead of the hot plate 8. It differs from the processing unit 2 in that the supply unit 205 is provided as a heating unit.

The organic solvent liquid supply unit 203 includes an organic solvent liquid pipe 206 for supplying the organic solvent liquid to the upper nozzle 29, an organic solvent liquid valve 207 for opening and closing the organic solvent liquid pipe 206, and an organic solvent liquid pipe 206. Includes a flow rate adjusting valve 208 for adjusting the discharge flow rate of the organic solvent liquid from the upper nozzle 29 by adjusting the opening degree of the above. Although not shown, the flow rate adjusting valve 208 includes a valve body having a valve seat inside, a valve body that opens and closes the valve seat, and an actuator that moves the valve body between an open position and a closed position. .. The same applies to other flow rate adjusting valves.

The hydrogen fluoride steam supply unit 204 includes a hydrogen fluoride steam pipe 209 for supplying hydrogen fluoride steam (HF vapor) to the upper nozzle 29 and a hydrogen fluoride steam valve for opening and closing the hydrogen fluoride steam pipe 209. Including 210. The hydrogen fluoride vapor (HF vapor) supplied to the hydrogen fluoride vapor pipe 209 may contain a carrier gas (for example, an inert gas such as nitrogen gas).

When the organic solvent liquid valve 207 is opened with the hydrogen fluoride vapor valve 210 closed, the organic solvent liquid is supplied to the upper nozzle 29, and the organic solvent liquid is directed downward from the central discharge port 33, for example, at room temperature. Is discharged.
On the other hand, when the hydrogen fluoride vapor valve 210 is opened with the organic solvent liquid valve 207 closed, hydrogen fluoride vapor is supplied to the upper nozzle 29, and hydrogen fluoride vapor is directed downward from the central discharge port 33. (HF vapor) is discharged. The discharge flow rate of hydrogen fluoride vapor from the central discharge port 33 can be changed by adjusting the opening degree of the flow rate adjusting valve 208.

The bottom surface supply unit 205 includes a bottom surface nozzle 211 that discharges the heating fluid upward, a heating fluid pipe 212 that guides the heating fluid to the bottom surface nozzle 211, and a heating fluid valve 213 interposed in the heating fluid pipe 212. At the upper end of the lower surface nozzle 211, a discharge port 211a facing the central portion of the lower surface (back surface) of the substrate W held by the spin chuck 5 is formed. When the heating fluid valve 213 is opened, the heating fluid is discharged upward from the discharge port 211a.

In this embodiment, the heating fluid is a heating liquid heated to a high temperature (eg, a temperature close to the boiling point of IPA (about 82.4 ° C.) (about 70-80 ° C.). As a type of heating liquid, pure water. (DIW) can be mentioned, but may be carbonated water, electrolytic ionized water, hydrogen water, ozone water, IPA (isopropyl alcohol) or hydrochloric acid water having a diluted concentration (for example, about 10 to 100 ppm). Further, instead of the heating liquid, a heating gas heated to a heating high temperature (for example, a temperature (about 70 to 80 ° C.) close to the boiling point (about 82.4 ° C.) of IPA) may be discharged.

FIG. 11 is a block diagram for explaining the electrical configuration of the main part of the substrate processing apparatus 201.
The control device 3 controls the operations of the spin motor 13, the opposing member elevating unit 37, the blocking plate rotating unit 36, the first nozzle moving unit 20, the second nozzle moving unit 24, and the like according to a predetermined program. Further, the control device 3 opens and closes the chemical liquid valve 19, the rinse liquid valve 23, the organic solvent liquid valve 207, the hydrogen fluoride vapor valve 210, the heating fluid valve 213, and the like according to a predetermined program. Further, the control device 3 adjusts the opening degree of the flow rate adjusting valve 208 according to a predetermined program.

FIG. 12 is a time chart for explaining a rinsing step (S3 in FIG. 5) and a drying step (S4 in FIG. 5) included in the second substrate processing example executed in the substrate processing apparatus 201. 13A to 13F are schematic diagrams for explaining the drying step (S4 in FIG. 5).
The second substrate processing example includes the same steps as those of steps S1 to S5 of FIG. 5, similarly to the first substrate processing example.

In the following, with reference to FIGS. 10 to 12, the second substrate processing example will be described focusing on a portion different from the first substrate processing example. 13A to 13F will be referred to as appropriate.
The drying step (S4 in FIG. 5) according to the second substrate treatment example includes a paddle step T11 (see FIG. 12) in which a liquid film (liquid film of the treatment liquid) 251 of the organic solvent liquid is held on the upper surface of the substrate W. In the atmosphere forming step T12 (see FIG. 12) in which the cutoff space 38 is filled (formed) with an atmosphere containing a large amount of hydrogen fluoride vapor, the organic solvent liquid is partially removed from the liquid film 251 of the organic solvent liquid. The liquid film removing region forming step T13 (see FIG. 12) for forming a circular liquid film removing region 252 in the central portion of the liquid film 251 of the organic solvent liquid, and the liquid film removing region 252 facing the outer periphery of the substrate W. It includes a liquid film removing region expanding step T14 (see FIG. 12) to be expanded, and a spin drying step T15 (see FIG. 12) in which the substrate W is shaken off and rotated at a drying rate to dry the upper surface of the substrate W.

The drying step (S4 in FIG. 5) according to the second substrate processing example will be described in detail.
Prior to the start of the paddle step T11, the control device 3 controls the opposing member elevating unit 37 to lower the blocking plate 27 from the retracted position to the close position. After the cutoff plate 27 is arranged at a close position, the control device 3 opens the organic solvent liquid valve 207 while closing the hydrogen fluoride vapor valve 210 while keeping the rotation of the substrate W at the paddle speed, and opens the cutoff plate 27. The organic solvent liquid is discharged from the central discharge port 33. As a result, the rinse liquid contained in the liquid film on the upper surface of the substrate W is sequentially replaced with the organic solvent liquid. As a result, as shown in FIG. 13A, a liquid film 251 of the organic solvent liquid covering the entire upper surface of the substrate W is held in a paddle shape on the upper surface of the substrate W (paddle step T11). The thickness of the bulk portion of the liquid film 251 of the organic solvent liquid is larger than the height of the pattern P. When almost all the liquid film on the entire upper surface of the substrate W is replaced with the liquid film 251 of the organic solvent liquid, the control device 3 closes the organic solvent liquid valve 207 and discharges the organic solvent liquid from the central discharge port 33. To stop. As a result, the paddle step T11 is completed.

When a silicon substrate is used as the substrate W, silicon oxide may be deposited on the liquid film 251 of the organic solvent liquid. This silicon oxide was produced in the chemical solution step (S2 in FIG. 5) for the substrate W, and remained on the substrate W until the drying step (S4 in FIG. 5).
After the discharge of the organic solvent liquid is stopped, the control device 3 controls the opposing member elevating unit 37 to lower the blocking plate 27 from the close position to the blocking position. As a result, a blocking space 38 (see FIG. 13B) is formed between the substrate facing surface 43 and the upper surface of the substrate W.

Further, after the discharge of the organic solvent liquid is stopped, the control device 3 opens the heating fluid valve 213. As a result, the heating fluid is discharged upward from the discharge port 211a of the lower surface nozzle 211, and the heating fluid is supplied to the lower surface (back surface) of the substrate W. As a result, the heating fluid discharged from the discharge port 211a of the lower surface nozzle 211 lands on the lower surface of the substrate W to form a liquid film of the heating fluid covering the lower surface of the substrate W. As a result, the substrate W is heated from the lower surface side, and the temperature of the liquid film 251 of the organic solvent liquid on the substrate W is raised (back surface heating step). Due to this heating, the liquid film 251 of the organic solvent liquid on the substrate W _{is higher than the melting point of H 2} SiF ₆ (about 19 ° C.) and lower than the boiling point of IPA (about 82.4 ° C.). It is warmed to a predetermined temperature). The discharge flow rate of the heating fluid from the lower surface nozzle 211 is set to a size such that the heating fluid does not wrap around from the peripheral edge portion of the substrate W to the surface side. By raising the temperature of the organic solvent liquid contained in the liquid film 251 of the organic solvent liquid, the performance of replacing the rinse liquid with the organic solvent can be improved.

Further, the control device 3 opens the hydrogen fluoride vapor valve 210 while closing the organic solvent liquid valve 207 while maintaining the rotation of the substrate W at the paddle speed, and fluorinated from the central discharge port 33 of the shutoff plate 27. Discharge hydrogen vapor. The discharge flow rate of hydrogen fluoride vapor at this time is a small flow rate (for example, about 5 (liters / minute). By discharging hydrogen fluoride vapor (HF vapor) from the central discharge port 33 for a predetermined time, the cutoff space 38 Is filled with hydrogen fluoride vapor (HF vapor) (atmosphere forming step T12).

When a predetermined period elapses from the end of the paddle step T11, the control device 3 controls the spin motor 13 to accelerate the rotation speed of the substrate W. Specifically, the control device 3 gradually increases the rotation speed of the substrate W toward the first rotation speed (for example, about 50 rpm). As the rotation speed of the substrate W increases, the centrifugal force due to the rotation of the substrate W increases, which causes the organic solvent liquid in the central portion of the substrate W to spread outward. As a result, as shown in FIG. 13C, the liquid film 251 of the organic solvent liquid is partially removed in the central portion of the substrate W, and as a result, a small-diameter circular liquid film removing region 252 is formed in the central portion of the substrate W. (Liquid film removal region forming step T13). The formation of the liquid film removing region 252 is performed in a state where the blocking space 38 is filled with hydrogen fluoride vapor (HF vapor). That is, the atmosphere around the boundary 253 (hereinafter, referred to as “liquid film boundary 253”) with the liquid film removing region 252 in the liquid film 251 of the organic solvent liquid is maintained in the atmosphere of hydrogen fluoride vapor (HF vapor).

After forming the liquid film removing region 252, the control device 3 controls the spin motor 13 to maintain the rotation speed of the substrate W at the first rotation speed (for example, about 50 rpm). As a result, the liquid film removing region 252 slowly expands (liquid film removing region expanding step T14). As the liquid film removing region 252 expands, the liquid film boundary 253 moves outward in the radial direction, as shown in FIG. 13D. As shown in FIG. 13E, in the liquid film removing region expansion step T14, the liquid film removing region 252 is expanded over the entire upper surface of the substrate W. That is, the liquid film boundary 253 also moves to the upper peripheral edge of the substrate W. The expansion of the liquid film removing region 252 is also performed in a state where the blocking space 38 is filled with hydrogen fluoride vapor (HF vapor) (hydrogen fluoride atmosphere holding step). That is, the liquid film boundary 253 moves from the central portion of the substrate W to the upper peripheral edge of the substrate W while the atmosphere around the liquid film boundary 253 is maintained by hydrogen fluoride vapor (HF vapor).

In the liquid film removing region expansion step T14, as the liquid film boundary 253 moves, the organic solvent liquid flows from between the patterns P (see FIG. 4) on the surface of the substrate W from the central portion of the substrate W to the upper peripheral edge of the substrate W. It is removed in order toward it. There is a difference in surface tension acting on the pattern P through which the liquid film boundary 253 passes, which causes the pattern P to momentarily collapse toward the bulk portion side (that is, the outside of the substrate W).

In the second substrate processing example, the liquid film boundary 253 moves from the center of the upper surface of the substrate W to the upper peripheral edge of the substrate W while the atmosphere around the liquid film boundary 253 is maintained by hydrogen fluoride vapor (HF vapor). .. When the atmosphere around the liquid film boundary 253 is maintained by hydrogen fluoride vapor (HF vapor), hydrogen fluoride contained in hydrogen fluoride vapor (HF vapor) is deposited on the liquid film 251 of the organic solvent liquid. and which reacts with silicon _oxide, it decomposes into and water H 2 SiF _6.

Therefore, hydrogen fluoride contained in the atmosphere around the liquid film boundary 253 reacts with the silicon oxide deposited on the liquid film 251 of the organic solvent liquid, and as a result, precipitates on the liquid film 251 of the organic solvent liquid. The silicon oxide is not attached to the tip Pa of the pattern P (see FIG. 4), or the silicon oxide (that is, the product 55 (see FIG. 9)) attached to the tip Pa of the pattern P is also present. It is removed from the tip Pa of the pattern P.

Further, in the liquid film removing region expansion step T14, the liquid film 251 of the organic solvent liquid is maintained at about 70 to 80 ° C. Therefore, the hydrogen fluoride contained in the hydrogen fluoride vapor (HF vapor) reacts with the silicon oxide to generate a residue of _{H 2} SiF _6. However, the evaporation of such a residue is promoted by contacting the silicon oxide with the organic solvent liquid having a liquid temperature of about 70 to 80 ° C. contained in the liquid film 251 of the organic solvent liquid. Since the melting point of H ₂ SiF ₆ is about 19 ° C., in an environment of about 70 to 80 ° C., the residue of evaporation is accelerated. Thereby, the residue can be evaporated and removed from the surface of the substrate W.

Further, since the liquid temperature of the liquid film 251 of the organic solvent liquid _{is higher than the melting point of H 2} SiF ₆ (about 19 ° C.) and lower than the boiling point of IPA (about 82.4 ° C.), the organic solvent liquid it can be a liquid film 251 while maintaining the _membrane, to better remove residual H 2 SiF _6.
As shown in FIG. 13F, after the liquid film removing region 252 expands to the entire upper surface of the substrate W, the control device 3 closes the heating fluid valve 213 to stop the discharge of the heating fluid to the lower surface of the substrate W. .. Further, the control device 3 adjusts the opening degree of the flow rate adjusting valve 208 to increase the discharge flow rate of hydrogen fluoride vapor (HF vapor) discharged from the central discharge port 33 to a large flow rate (for example, about 150 (liters / minute)). The control device 3 further accelerates the rotation of the substrate W to a shake-off drying rate (for example, about 1500 rpm), whereby the liquid on the upper surface of the substrate W can be shaken off, whereby the substrate W can be shaken off. The upper surface of W can be completely dried.

After the drying step (S4 in FIG. 5) is completed, the control device 3 controls the opposing member elevating unit 37 to raise the blocking plate 27 from the retracted position to the close position. As a result, the blocking space 38 disappears. Further, the control device 3 closes the hydrogen fluoride vapor valve 210 to stop the discharge of hydrogen fluoride vapor (HF vapor) from the central discharge port 33. After that, the substrate W is carried out by the transfer robot CR.

As described above, according to the second embodiment, the action and effect equivalent to the action and effect described in relation to the first embodiment are exhibited.
FIG. 14 is a schematic cross-sectional view for explaining a configuration example of the processing unit 302 provided in the substrate processing apparatus 301 according to the third embodiment of the present invention.
In the embodiment shown in the third embodiment, the same reference numerals as those in the cases of FIGS. 10 to 13F are attached to the parts common to the above-mentioned second embodiment, and the description thereof will be omitted.

The treatment unit 302 replaces the organic solvent liquid supply unit 203 (see FIG. 10) and the hydrogen fluoride vapor supply unit 204 (see FIG. 10) with an IPA (IPA) of an example of an organic solvent liquid having a surface tension lower than that of water. An organic solvent liquid supply unit 303 for supplying vapor containing (isopropyl alcohol) (hereinafter referred to as "organic solvent vapor") onto the substrate W held by the spin chuck 5, and a substrate held by the spin chuck 5. It differs from the processing unit 202 according to the second embodiment in that it includes a hydrogen fluoride vapor supply unit 304 for supplying hydrogen fluoride vapor (HF vapor) on W. Further, the processing unit 202 supplies hot water, which is an example of a heating fluid, to the lower surface of the substrate W held by the spin chuck 5 (the back surface opposite to the pattern forming surface) instead of the hot plate 8. The supply unit 205 is provided as a heating unit.

Further, the processing unit 302 is different from the processing unit 202 in that the processing unit 302 includes a rinsing liquid supply unit 305 for supplying the rinsing liquid on the substrate W held by the spin chuck 5 instead of the rinsing liquid supply unit 7. doing.
The organic solvent liquid supply unit 303 includes an organic solvent vapor pipe 306 for supplying organic solvent vapor to the upper nozzle 29, an organic solvent vapor valve 307 for opening and closing the organic solvent vapor vapor pipe 306, and an organic solvent vapor vapor pipe 306. It includes a flow rate adjusting valve 308 for adjusting the opening degree and adjusting the supply flow rate of the organic solvent vapor to the upper nozzle 29. The organic solvent vapor supplied to the organic solvent vapor pipe 306 may contain a carrier gas (for example, an inert gas such as nitrogen gas).

The hydrogen fluoride steam supply unit 304 includes a hydrogen fluoride steam pipe 309 for supplying hydrogen fluoride steam (HF vapor) to the upper nozzle 29 and a hydrogen fluoride steam valve for opening and closing the hydrogen fluoride steam pipe 309. It includes 310 and a flow rate adjusting valve 311 for adjusting the opening degree of the hydrogen fluoride steam pipe 309 to adjust the supply flow rate of hydrogen fluoride steam to the upper nozzle 29. The hydrogen fluoride vapor (HF vapor) supplied to the hydrogen fluoride vapor pipe 309 may contain a carrier gas (for example, an inert gas such as nitrogen gas).

The rinse liquid supply unit 305 includes a rinse liquid pipe 312 for supplying the rinse liquid to the upper nozzle 29, and a rinse liquid valve 313 for opening and closing the rinse liquid pipe 312.
When the rinse liquid valve 313 is closed and the organic solvent vapor valve 307 and the hydrogen fluoride vapor valve 310 are opened at the same time, the organic solvent vapor and the hydrogen fluoride vapor are supplied to the upper nozzle 29, and the organic solvent is supplied. An organic solvent / hydrogen fluoride mixed vapor (IPA / HF vapor) containing hydrogen fluoride and hydrogen fluoride is discharged downward from the central discharge port 33. Further, the discharge flow rate of the organic solvent / hydrogen fluoride mixed vapor (IPA / HF vapor) of the hydrogen fluoride vapor from the central discharge port 33 is adjusted by adjusting the opening degree of the flow rate adjusting valve 308 and adjusting the opening degree of the flow rate adjusting valve 311. Can be changed by.

On the other hand, when the rinse liquid valve 313 is opened with the organic solvent vapor valve 307 and the hydrogen fluoride vapor valve 310 closed, the rinse liquid valve 313 is supplied to the upper nozzle 29 and faces downward from the central discharge port 33. Rinse liquid is discharged.
FIG. 15 is a block diagram for explaining the electrical configuration of the main part of the substrate processing apparatus 301.

The control device 3 controls the operations of the spin motor 13, the opposing member elevating unit 37, the blocking plate rotating unit 36, the first nozzle moving unit 20, and the like according to a predetermined program. Further, the control device 3 opens and closes the chemical solution valve 19, the rinse solution valve 23, the heating fluid valve 213, the organic solvent vapor valve 307, the hydrogen fluoride vapor valve 310, the rinse solution valve 313, and the like according to a predetermined program. Further, the control device 3 adjusts the opening degrees of the flow rate adjusting valves 308 and 311 according to a predetermined program.

FIG. 16 is a time chart for explaining a rinsing step (S3 in FIG. 5) and a drying step (S4 in FIG. 5) included in the third substrate processing example executed in the substrate processing apparatus 301. 17A to 17F are schematic views for explaining a drying step (S4 in FIG. 5).
The third substrate processing example includes the same steps as those of steps S1 to S5 of FIG. 5, similarly to the first substrate processing example and the second substrate processing example.

In the following, with reference to FIGS. 14 to 16, the third substrate processing example will be described focusing on a portion different from the second substrate processing example. 17A to 17F will be referred to as appropriate.
In the rinsing step (S3 in FIG. 5, including the paddle rinsing step T41) according to the second substrate processing example, the rinsing liquid discharged from the central discharge port 33 is used to rinse the upper surface of the substrate W. Be given. Specifically, the control device 3 opens the rinse liquid valve 313 while closing the organic solvent vapor valve 307 and the hydrogen fluoride vapor valve 310. As a result, the rinse liquid is discharged from the central discharge port 33. In the paddle rinsing step T41, the rotation speed of the substrate W is maintained at the paddle speed. As a result, as shown in FIG. 17A, a liquid film 351 of the rinse liquid (liquid film of the treatment liquid) covering the entire upper surface of the substrate W is held in a paddle shape on the upper surface of the substrate W. The thickness of the bulk portion of the liquid film 351 of the rinse liquid is larger than the height of the pattern P. When a predetermined period elapses after decelerating the substrate W to the paddle speed, the control device 3 closes the rinse liquid valve 313 and stops the discharge of the rinse liquid from the central discharge port 33. After that, a drying step (S4 in FIG. 5) is executed.

In the drying step (S4 in FIG. 5) according to the third substrate treatment example, the barrier space 38 is filled (formed) with an atmosphere containing a large amount of organic solvent / hydrogen fluoride mixed vapor (IPA / HF vapor). Forming step T22 (see FIG. 16) and a liquid film in which the organic solvent liquid is partially removed from the liquid film 351 of the rinse liquid to form a circular liquid film removing region 352 in the central portion of the liquid film 351 of the rinse liquid. The removal region forming step T23 (see FIG. 16), the liquid film removing region expanding step T24 (see FIG. 16) for expanding the liquid film removing region 352 toward the outer periphery of the substrate W, and the substrate W being shaken off and rotated at a drying speed. A spin-drying step T25 (see FIG. 16) for drying the upper surface of the substrate W is included. That is, the drying step (S4 in FIG. 5) according to the third substrate processing example does not include a step corresponding to the paddle step T1 (see FIG. 6) and the paddle step T11 (see FIG. 12).

The drying step (S4 in FIG. 5) according to the third substrate processing example will be described in detail.
When a silicon substrate is used as the substrate W, silicon oxide may be deposited on the liquid film 351 of the rinsing liquid. This silicon oxide was produced in the chemical solution step (S2 in FIG. 5) for the substrate W, and remained on the substrate W until the drying step (S4 in FIG. 5).

Prior to the start of the atmosphere forming step T22, the control device 3 controls the facing member elevating unit 37 to lower the blocking plate 27 from the retracted position to the blocking position. As a result, a blocking space 38 (see FIG. 17B) is formed between the substrate facing surface 43 and the upper surface of the substrate W.
Further, after the discharge of the organic solvent liquid is stopped, the control device 3 opens the heating fluid valve 213. As a result, the substrate W is heated from the lower surface side, and the temperature of the rinse liquid film 351 on the substrate W is raised to about 70 to 80 ° C.

Further, the control device 3 closes the rinse liquid valve 313 and simultaneously opens the organic solvent vapor valve 307 and the hydrogen fluoride vapor valve 310 while maintaining the rotation of the substrate W at the paddle speed, and the center of the shutoff plate 27. The organic solvent / hydrogen fluoride mixed vapor (IPA / HF valve) is discharged from the unit discharge port 33. The discharge flow rate of the organic solvent / hydrogen fluoride mixed vapor (IPA / HF vapor) at this time is a small flow rate (for example, about 5 (liters / minute). By discharging the IPA / HF vapor) for a predetermined time, the blocking space 38 is filled with the organic solvent / hydrogen fluoride mixed vapor (IPA / HF vapor) (atmosphere forming step T22).

When a predetermined period elapses from the end of the paddle rinse step T41, the control device 3 controls the spin motor 13 to accelerate the rotation speed of the substrate W. Specifically, the control device 3 gradually increases the rotation speed of the substrate W toward the first rotation speed (for example, about 50 rpm). As the rotation speed of the substrate W increases, the centrifugal force due to the rotation of the substrate W increases, which causes the organic solvent liquid in the central portion of the substrate W to spread outward. As a result, as shown in FIG. 17C, the liquid film 351 of the rinse liquid is partially removed in the central portion of the substrate W, and as a result, a small-diameter circular liquid film removing region 352 is formed in the central portion of the substrate W. (Liquid film removal region forming step T23). The formation of the liquid film removing region 352 is performed in a state where the blocking space 38 is filled with the organic solvent / hydrogen fluoride mixed vapor (IPA / HF vapor). That is, the atmosphere around the boundary 353 (hereinafter referred to as "liquid film boundary 353") with the liquid film removing region 352 in the liquid film 351 of the rinse liquid is the atmosphere of the organic solvent / hydrogen fluoride mixed vapor (IPA / HF vapor). Is kept in.

After forming the liquid film removing region 352, the control device 3 controls the spin motor 13 to maintain the rotation speed of the substrate W at the first rotation speed (for example, about 50 rpm). As a result, the liquid film removing region 352 slowly expands (liquid film removing region expanding step T24). As the liquid film removing region 352 expands, the liquid film boundary 353 moves outward in the radial direction, as shown in FIG. 17D. As shown in FIG. 17E, in the liquid film removing region expanding step T24, the liquid film removing region 352 is expanded over the entire upper surface of the substrate W. That is, the liquid film boundary 353 also moves to the upper peripheral edge of the substrate W. The expansion of the liquid film removing region 352 is also performed in a state where the blocking space 38 is filled with the organic solvent / hydrogen fluoride mixed vapor (IPA / HF vapor) (hydrogen fluoride atmosphere holding step). That is, the liquid film boundary 353 moves from the central portion of the substrate W to the upper peripheral edge of the substrate W while the atmosphere around the liquid film boundary 353 is maintained by the organic solvent / hydrogen fluoride mixed vapor (IPA / HF vapor). ..

In the liquid film removing region expansion step T24, as the liquid film boundary 353 moves, the rinse liquid is directed from the central portion of the substrate W to the upper peripheral edge of the substrate W from between the patterns P (see FIG. 4) on the surface of the substrate W. Will be removed in order. There is a difference in surface tension acting on the pattern P through which the liquid film boundary 353 passes, which causes the pattern P to momentarily collapse toward the bulk portion side (that is, the outer side of the substrate W).

In the third substrate treatment example, the liquid film boundary 353 is moved from the center of the upper surface of the substrate W to the substrate W while the atmosphere around the liquid film boundary 353 is maintained by the organic solvent / hydrogen fluoride mixed vapor (IPA / HF vapor). Move to the upper edge of the surface. When the atmosphere around the liquid film boundary 353 is maintained in the organic solvent / hydrogen fluoride mixed vapor (IPA / HF vapor), the hydrogen fluoride contained in the organic solvent / hydrogen fluoride mixed vapor (IPA / HF vapor) is contained. but reacts with silicon oxide which is deposited on the liquid film 351 of the rinsing liquid, decomposes and water H ₂ SiF _6.

Therefore, hydrogen fluoride contained in the atmosphere around the liquid film boundary 353 reacts with the silicon oxide deposited on the liquid film 351 of the rinse liquid, and as a result, it is precipitated on the liquid film 351 of the rinse liquid. The silicon oxide does not adhere to the tip Pa of the pattern P (see FIG. 4), or the silicon oxide (that is, the product 55 (see FIG. 9)) adhering to the tip Pa of the pattern P also has the pattern. It is removed from the tip Pa of P.

Further, in the liquid film removing region expansion step T24, the liquid film 351 of the rinse liquid is maintained at about 70 to 80 ° C. Therefore, hydrogen fluoride contained in the organic solvent / hydrogen fluoride mixed vapor (IPA / HF vapor) reacts with the silicon oxide to generate a residue of _{H 2} SiF _6. However, the evaporation of such a residue is promoted by contacting the silicon oxide with the rinsing liquid having a liquid temperature of about 70 to 80 ° C. contained in the liquid film 351 of the rinsing liquid. Since the melting point of H ₂ SiF ₆ is about 19 ° C., in an environment of about 70 to 80 ° C., the residue of evaporation is accelerated. Thereby, the residue can be evaporated and removed from the surface of the substrate W.

Further, in the third substrate treatment example, the liquid film boundary 353 moves toward the outer periphery of the substrate W while keeping the circumference of the liquid film boundary 353 in the liquid film 351 of the rinse liquid as the organic solvent vapor. In the vicinity of the liquid film boundary 353 inside the liquid film 351 of the rinse liquid, marangoni convection flowing in a direction away from the liquid film boundary 353 is generated due to the difference in the concentration of the organic solvent. Therefore, regardless of the position of the liquid film boundary 353, marangoni convection continues to occur in the vicinity of the liquid film boundary 353 inside the liquid film 351 of the rinse liquid.

Particles removed by the chemical solution step (S2 in FIG. 5) or the like may be contained in the liquid film 351 of the rinse solution. Even if particles are contained in the vicinity of the liquid film boundary 353 inside the liquid film 351 of the rinse liquid, the particles receive malangoni convection and are directed toward the bulk portion of the rinse liquid, that is, from the liquid film boundary 353. It moves in the direction of separation, and the particles continue to be taken into the liquid film 351 of the rinsing liquid.

Therefore, as the liquid film removing region 352 expands, the liquid film boundary 353 moves toward the outer periphery of the substrate W while the particles are taken into the bulk portion of the liquid film 351 of the rinse liquid. Then, the particles are discharged from the upper surface of the substrate W together with the liquid film 351 of the rinse liquid without appearing in the liquid film removing region 352. As a result, no particles remain on the upper surface of the substrate W after the substrate W is dried. Therefore, it is possible to suppress or prevent the generation of particles when the substrate W is dried.

As shown in FIG. 17F, after the liquid film removing region 352 expands to the entire upper surface of the substrate W, the control device 3 closes the heating fluid valve 213 to stop the discharge of the heating fluid to the lower surface of the substrate W. .. Further, the control device 3 adjusts the opening degree of the flow rate adjusting valves 308 and 311 to increase the discharge flow rate of the organic solvent / hydrogen fluoride mixed vapor (IPA / HF vapor) discharged from the central discharge port 33. Raise to (for example, about 150 (liters / minute)). Further, the control device 3 further accelerates the rotation of the substrate W to a shake-off drying speed (for example, about 1500 rpm). As a result, the liquid on the upper surface of the substrate W can be shaken off, whereby the upper surface of the substrate W can be completely dried.

After the drying step (S4 in FIG. 5) is completed, the control device 3 controls the opposing member elevating unit 37 to raise the blocking plate 27 from the retracted position to the close position. As a result, the blocking space 38 disappears. Further, the control device 3 closes the organic solvent steam valve 307 and the hydrogen fluoride steam valve 310 to stop the discharge of the organic solvent / hydrogen fluoride mixed vapor (IPA / HF vapor) from the central discharge port 33. After that, the substrate W is carried out by the transfer robot CR.

As described above, according to the third embodiment, the action and effect equivalent to the action and effect described in relation to the first embodiment are exhibited.
<Recovery test>
Next, a recovery test for recovering the collapsed pattern will be described. A semiconductor substrate having a pattern having an aspect ratio of AR16 was used as a sample for the first recovery test. A spin-drying step (corresponding to S5 in FIG. 5) was performed on two samples (sample 1 and sample 2) to collapse the pattern of each sample. The pattern collapse rates in each sample are almost the same.

Sample 1: After that, sample 1 is placed in a blocking space (a space in which the atmosphere is substantially blocked from the surroundings), and while heating sample 1 from the back surface side to about 120 ° C., an IPA solution at about 75 ° C. is applied to the surface of sample 1. In that state, the sample was exposed to the atmosphere in the blocking space for 0.5 minutes. The dropping amount of the IPA solution was about 1 (milliliter).
Sample 2: After that, sample 1 is placed in a blocking space, and while heating sample 1 from the back surface side to about 120 ° C., an IPA / hydrofluoric acid mixed solution at about 75 ° C. is dropped onto the surface of sample 2, and in that state. , 0.5 minutes, exposed to the atmosphere in the blocked space. The dropping amount of the IPA / hydrofluoric acid mixed solution was about 1 (milliliter). The mixing ratio of the IPA solution and hydrofluoric acid (concentrated hydrofluoric acid having a concentration of 50%) in the IPA / hydrofluoric acid mixed solution was 100: 1 by volume.

Then, the samples 1 and 2 were taken out from the cut-off space, and the number of collapsed patterns was determined by analyzing the image by SEM. The collapse rate of sample 1 was as high as 10.6%, whereas the collapse rate of sample 2 was as low as 2.5%.
Further, FIGS. 18A and 18B show SEM image diagrams of Sample 1 and Sample 2, respectively.

Although the three embodiments of the present invention have been described above, the present invention can also be implemented in other embodiments.
For example, as shown in FIG. 19, in the second and third embodiments, a plurality of upper surface nozzles 401 penetrating the blocking plate 27 are provided, and hydrogen fluoride vapor (hydrogen fluoride vapor) is provided in accordance with the expansion of the liquid film removal region 252,352. The top nozzle 401 for discharging HF vapor) or organic solvent / hydrogen fluoride mixed vapor (IPA / HF vapor) may be changed. The upper surface nozzle 401 includes a central nozzle 402 located on the rotation axis A1 of the substrate W and a plurality of peripheral nozzles 403 arranged at positions separated from the rotation axis A1. The plurality of peripheral nozzles 403 are inserted into insertion holes 404 that penetrate the blocking plate 27 vertically, and the discharge ports formed at the lower ends thereof face the inside of the blocking space 38. Hydrogen fluoride vapor (HF vapor) or organic solvent / hydrogen fluoride mixed vapor (IPA / HF vapor) is supplied to the plurality of peripheral nozzles 403 and each peripheral nozzle individually via a valve 405. ing.

In the liquid film removing region expansion step (T14 in FIG. 12 or T24 in FIG. 16), the liquid film boundary 253, 353 is directed from the central portion to the peripheral edge of the substrate W as the liquid film removing region 252,352 is expanded. And move. At this time, only the upper surface nozzle 401 (that is, the upper surface nozzle 401 closest to the liquid film boundary 253, 353) optimal for supplying to the moving liquid film boundary 253, 353 is hydrogen fluoride vapor (HF vapor) or an organic solvent. / Hydrogen fluoride mixed vapor (IPA / HF vapor) may be discharged. That is, as the liquid film removing region 252,352 expands, the upper surface nozzle 401 that discharges hydrogen fluoride vapor (HF vapor) or organic solvent / hydrogen fluoride mixed vapor (IPA / HF vapor) may be switched.

Further, although it has been described that the first to third substrate processing examples are executed in the chamber 4, the first to third substrate processing examples may be performed in a closed chamber in which the internal space is sealed from the surroundings. Good. The internal space of the closed chamber corresponds to the blocking space according to the present invention.
Further, in parallel with the liquid film removal region expansion step (T4 in FIG. 6, T14 in FIG. 12, T24 in FIG. 16) according to the first to third substrate processing examples, the blocking plate 27 is rotated around the rotation axis A2. You may let me.

Further, in the spin-drying step T15 (see FIG. 12) according to the second substrate processing example and the spin-drying step T25 (see FIG. 16) according to the third substrate processing example, the spin-drying steps T15 and T25 are predetermined from the start. When the period elapses, the discharge of hydrogen fluoride vapor (HF vapor) or organic solvent / hydrogen fluoride mixed vapor (IPA / HF vapor) from the central discharge port 33 is interrupted, and then the surrounding discharge port 35 The inert gas from the above may be supplied to the cutoff space 38.

Further, in the first embodiment, it has been described that the organic solvent / hydrofluoric acid mixed solution at room temperature is supplied to the upper surface of the substrate W, but the organic solvent / hydrofluoric acid mixed solution at about 70 to 80 ° C. is the upper surface of the substrate W. It may be supplied to.
Further, in the first embodiment, it has been described that the organic solvent / hydrofluoric acid mixed liquid is supplied to the upper surface of the substrate W by discharging the organic solvent / hydrofluoric acid mixed liquid from the central discharge port 33. The organic solvent liquid and hydrofluoric acid may be individually discharged from a plurality of discharge ports provided on the substrate facing surface 43, and the organic solvent liquid and hydrofluoric acid may be mixed on the upper surface of the substrate W.

Further, in the first embodiment, as an example of the liquid film of the treatment liquid formed on the upper surface of the substrate W, an organic solvent / hydrofluoric acid mixed liquid is given as an example, but the liquid film of the treatment liquid is a liquid of a hydrofluoric acid-containing liquid. A film is sufficient, and in addition to the organic solvent / hydrofluoric acid mixture, a film of a mixture of hydrofluoric acid and other liquids (for example, functional water (ozone water, hydrogen water, carbonated water)) or a hydrofluoric acid solution. A membrane can be exemplified.
Further, in the second embodiment, it has been described that the organic solvent liquid at room temperature is supplied to the upper surface of the substrate W, but the organic solvent liquid at about 70 to 80 ° C. is supplied to the upper surface of the substrate W. You may.

Further, in the first and second embodiments, the rinse liquid supply unit 305 according to the third embodiment may be used instead of the rinse liquid supply unit 7 to supply the rinse liquid to the upper surface of the substrate. .. That is, the rinse liquid may be discharged from the central discharge port 33.
Further, in the first to third embodiments, IPA has been exemplified as an example of an organic solvent, but methanol, ethanol, HFE (hydrofluoroether), acetone and the like can also be exemplified as the organic solvent. Further, the organic solvent may be a fluid mixed with other components as well as a case where it is composed of only a single component. For example, it may be a mixture of IPA and acetone, or it may be a mixture of IPA and methanol.

Further, in the substrate processing apparatus 1 according to the first embodiment, the bottom surface supply unit 205 may be adopted as the heating unit. On the contrary, the hot plate 8 may be adopted as the heating unit in the substrate processing devices 201 and 301 according to the second or third embodiment.
Further, the heating unit may be omitted. In this case, in the liquid film removing region expansion step (T4 in FIG. 6, T14 in FIG. 12, T24 in FIG. 16) according to the first to third substrate treatment examples, the treatment liquid contained in the liquid film of the treatment liquid is kept at room temperature. You may have.

Further, in each of the above-described embodiments, the case where the substrate processing devices 1,201 and 301 are devices for processing the disk-shaped substrate W has been described, but the substrate processing devices 1,201 and 301 are for the liquid crystal display device. It may be an apparatus for processing a polygonal substrate such as a glass substrate.
In addition, various design changes can be made within the scope of the matters described in the claims.

1: Substrate processing device 3: Control device 5: Spin chuck (board holding unit, rotating unit)
8: Hot plate (heating unit)
9: Opposing member (blocking space forming unit)
10: Organic solvent / hydrofluoric acid mixed liquid supply unit (hydrofluoric acid-containing liquid supply unit)
37: Opposing member elevating unit (blocking space forming unit)
51: Liquid film of organic solvent / hydrofluoric acid mixture (liquid film of hydrofluoric acid-containing liquid)
52: Liquid film removal area 53: Liquid film boundary (boundary between the liquid film removal area and the liquid film of the hydrofluoric acid-containing liquid)
55: Product (foreign matter)
61: Structure 201: Substrate processing device 204: Hydrogen fluoride vapor supply unit 205: Bottom surface supply unit (heating unit)
251: Liquid film of organic solvent liquid (liquid film of treatment liquid)
252: Liquid film removal area 253: Liquid film boundary (boundary between the liquid film removal area and the liquid film of the treatment liquid)
301: Substrate processing device 304: Hydrogen fluoride vapor supply unit 351: Rinse liquid film (treatment liquid film)
352: Liquid film removal area 353: Liquid film boundary (boundary between the liquid film removal area and the liquid film of the treatment liquid)

Claims (3)

A substrate processing method for processing a substrate having a pattern including a plurality of convex structures on its surface.
It includes a foreign matter removing step of removing foreign matter that adheres to each other adjacent structures that are about to fall down from the structure by exposing it to steam containing hydrogen fluoride.
A substrate processing method for elastically restoring a collapsed structure to an upright state by removing the foreign matter from the structure. The substrate processing method according to claim 1, further comprising a back surface heating step of heating the back surface of the substrate in parallel with the foreign matter removing step. A substrate holding unit that holds a substrate having a pattern including a plurality of convex structures on its surface,
A steam supply unit for supplying steam containing hydrogen fluoride to the surface of the substrate, and
Including a control device for controlling the steam supply unit.
The control device executes a foreign matter removing step of removing foreign matter that adheres to the structures adjacent to each other that have fallen down from the structure by supplying the steam to the surface of the substrate.
A substrate processing device that elastically restores a collapsed structure to an upright state by removing the foreign matter from the structure.

Images