JP2015185756A - Substrate processing method and substrate processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate processing method capable of efficiently freezing a liquid film covering a top face of a substrate in frozen cleaning and to provide a substrate processing apparatus.SOLUTION: A liquid is provided to a lower face of a substrate before freezing a liquid film covering a top face of the substrate. Then, in parallel to freezing the liquid film, a gas as an evaporation acceleration gas is provided to the lower face of the substrate. Since the lower face of the substrate is wet, when the gas is provided to the lower face of the substrate, the liquid at the lower face of the substrate is evaporated. The frozen liquid film is thawed and removed. Then, the substrate is dried.

Description

  The present invention relates to a substrate processing method and a substrate processing apparatus for processing a substrate. Examples of substrates to be processed include semiconductor wafers, liquid crystal display substrates, plasma display substrates, FED (Field Emission Display) substrates, optical disk substrates, magnetic disk substrates, magneto-optical disk substrates, and photomasks. Substrate, ceramic substrate, solar cell substrate and the like.

In a manufacturing process of a semiconductor device or a liquid crystal display device, a cleaning process is performed to remove contaminants such as particles from a substrate such as a semiconductor wafer or a glass substrate for a liquid crystal display device.
Patent Document 1 and Patent Document 2 disclose a single-wafer type substrate processing apparatus that performs freeze cleaning. Freezing cleaning is a cleaning method in which a liquid film covering the upper surface of a substrate is frozen and then the thawed liquid film is removed from the substrate.

In the freeze cleaning of Patent Document 1, the supply of pure water to the lower surface of the substrate is stopped before the freezing of the pure water liquid film covering the upper surface of the substrate is started (see paragraphs 0023 to 0027 of Patent Document 1). . Patent Document 1 does not disclose supplying gas to the lower surface of the substrate.
In the freeze cleaning of Patent Document 2, cooled pure water and nitrogen gas are supplied to the lower surface of the substrate during a period in which a liquid film of pure water (DIW) covering the upper surface of the substrate is frozen (Patent Document 2). Paragraphs 0041-0044). In paragraph 0055 of Patent Document 2, it is described that the temperature of the cooling gas supplied to the lower surface of the substrate needs to be lower than the freezing point of pure water.

JP 2013-138073 A JP 2010-80584 A

  In the conventional freeze cleaning, since it was thought that there was a possibility that the freezing of the liquid film might be hindered, the liquid and the gas were not supplied to the lower surface of the substrate during the period of freezing the liquid film. Therefore, in the freeze cleaning of Patent Document 1, the supply of pure water to the lower surface of the substrate is stopped before the freezing of the liquid film is started. In the freezing cleaning of Patent Document 2, although cooled pure water and nitrogen gas are supplied to the lower surface of the substrate, both fluids are cooled and care is taken so as not to prevent freezing of the liquid film. Yes. In particular, the temperature of the cooling gas supplied to the lower surface of the substrate is lower than the freezing point of pure water.

Although freezing cleaning has the advantage that the adhesion force of particles to the substrate can be weakened by the force generated by freezing the liquid film, the cost for generating cold water and cooling gas is generated, so the cost required for processing the substrate is increased. It will increase.
Accordingly, one of the objects of the present invention is to provide a substrate processing method and a substrate processing apparatus capable of efficiently freezing a liquid film covering the upper surface of a substrate in freeze cleaning.

  The invention according to claim 1 for achieving the object includes a liquid film forming step of forming a liquid film covering an upper surface of a substrate, a freezing step of freezing the liquid film after the liquid film forming step, Prior to the start of the freezing step, a liquid is supplied to the lower surface of the substrate by supplying a liquid, and a gas is supplied to the lower surface of the substrate in parallel with the freezing step. And a gas supply step for evaporating the liquid on the lower surface of the substrate.

  According to this method, the liquid is supplied to the lower surface of the substrate before the liquid film covering the upper surface of the substrate is frozen. Thereafter, in parallel with freezing the liquid film, a gas as an evaporation promoting gas is supplied to the lower surface of the substrate. Since the lower surface of the substrate is wet, when gas is supplied to the lower surface of the substrate, the liquid on the lower surface of the substrate evaporates, and the heat of the substrate is absorbed by the liquid as heat of vaporization. Therefore, the substrate is cooled while the liquid film is frozen. Thereby, the liquid film covering the upper surface of the substrate can be efficiently frozen. Therefore, the temperature of the frozen film formed by freezing the liquid film can be lowered. Alternatively, the entire liquid film on the substrate can be frozen in a shorter time. The particle removal rate increases as the temperature of the frozen film decreases. Therefore, the particle removal rate can be increased. In addition, if the liquid film is frozen in a shorter time, the consumption of the cooling gas can be reduced, so that the cost required for processing the substrate can be reduced.

  According to the second aspect of the present invention, the liquid supply step supplies the liquid to the lower surface of the substrate while supplying the gas to the lower surface of the substrate before the freezing step is started. A step of wetting a lower surface, wherein the gas supplying step supplies the gas to the lower surface of the substrate at a supply flow rate larger than the gas supply flow rate in the liquid supply step in parallel with the freezing step. The substrate processing method according to claim 1, comprising a step of evaporating the liquid on the lower surface of the substrate. The type of gas supplied to the substrate in the liquid supply step may be the same as or different from the gas supplied to the substrate in the gas supply step. The temperature may be the same or different.

  According to this method, a large flow rate of gas is supplied to the lower surface of the substrate while the liquid film is frozen. Thereby, the evaporation of the liquid on the lower surface of the substrate is further promoted. Thereby, the liquid film covering the upper surface of the substrate can be efficiently frozen. Moreover, since gas is not always supplied with a large flow rate, but the gas flow rate is temporarily increased, an increase in gas consumption can be suppressed. Thereby, the increase in the cost required for processing the substrate can be suppressed.

A third aspect of the present invention is the substrate processing method according to the first or second aspect, wherein the gas supplied to the lower surface of the substrate in the gas supplying step is a room temperature gas.
According to this method, a normal temperature gas is supplied to the lower surface of the substrate while the liquid film is frozen. Therefore, it is not necessary to adjust the temperature of the gas supplied to the lower surface of the substrate. Therefore, the cost required for adjusting the gas temperature can be reduced. Thereby, the cost required for processing the substrate can be reduced.

The invention described in claim 4 is the substrate processing method according to any one of claims 1 to 3, wherein the liquid supplied to the lower surface of the substrate in the liquid supply step is a liquid having a temperature lower than room temperature. is there.
According to this method, before the liquid film covering the upper surface of the substrate is frozen, the liquid having a temperature lower than room temperature is supplied to the lower surface of the substrate. Thereby, the substrate and the liquid film are cooled. Or the temperature rise of a board | substrate and a liquid film is suppressed. Therefore, the liquid film covering the upper surface of the substrate can be efficiently frozen.

The invention according to claim 5 is the substrate processing according to any one of claims 1 to 4, wherein the liquid supplied to the lower surface of the substrate in the liquid supply step is a liquid having higher volatility than water. Is the method.
According to this method, before the liquid film covering the upper surface of the substrate is frozen, a liquid that is more volatile than water is supplied to the lower surface of the substrate. Therefore, the lower surface of the substrate gets wet with a liquid that easily evaporates. Since the liquid adhering to the lower surface of the substrate easily evaporates, the liquid on the lower surface of the substrate can be efficiently evaporated by supplying gas. Thereby, a board | substrate can be cooled efficiently.

  According to a sixth aspect of the present invention, there is provided a substrate holding means for holding a substrate, a liquid film forming means for forming a liquid film covering an upper surface of the substrate held by the substrate holding means, and freezing for freezing the liquid film. And a liquid supply means for wetting the lower surface of the substrate by supplying liquid to the lower surface of the substrate held by the substrate holding means; and a gas is supplied to the lower surface of the substrate held by the substrate holding means Accordingly, the substrate processing apparatus includes a gas supply unit that evaporates the liquid on the lower surface of the substrate, and a control unit that controls the liquid film forming unit, the freezing unit, the liquid supply unit, and the gas supply unit. The control means includes a liquid film forming step for forming a liquid film covering an upper surface of the substrate, a freezing step for freezing the liquid film after the liquid film forming step, and before the freezing step is started. In parallel with the liquid supply step for wetting the lower surface of the substrate by supplying liquid to the lower surface of the substrate and the freezing step, the gas for evaporating the liquid on the lower surface of the substrate by supplying gas to the lower surface of the substrate And a supply step. According to this configuration, it is possible to achieve an effect similar to the effect described with respect to the invention of claim 1.

It is the schematic diagram which looked at the inside of the processing unit with which the substrate processing apparatus concerning one embodiment of the present invention was equipped horizontally. It is a time chart which shows an example of the processing performed by a processing unit. It is a schematic diagram which shows the state of a board | substrate when the process shown in FIG. 2 is performed.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a schematic view of the inside of a processing unit 2 provided in a substrate processing apparatus 1 according to an embodiment of the present invention viewed horizontally.
The substrate processing apparatus 1 is a single-wafer type apparatus that processes a disk-shaped substrate W such as a semiconductor wafer one by one. The substrate processing apparatus 1 includes a processing unit 2 that processes the substrate W, a transfer robot (not shown) that transfers the substrate W to the processing unit 2, and a control device 3 that controls the substrate processing apparatus 1.

  The processing unit 2 is a single-wafer type unit that processes a plurality of substrates W one by one using a processing liquid. The processing unit 2 includes a box-shaped chamber 4 having an internal space, and a substrate W around the vertical rotation axis A1 passing through the central portion of the substrate W while holding a single substrate W in a horizontal posture in the chamber 4. A spin chuck 5 for rotating W. The processing unit 2 further includes a cup 37 surrounding the spin chuck 5 around the rotation axis A1, and a disc-shaped blocking plate 39 disposed above the spin chuck 5 in a horizontal posture.

  The spin chuck 5 includes a disc-shaped spin base 6 held in a horizontal posture, a plurality of chuck pins 7 projecting upward from the outer peripheral portion of the upper surface of the spin base 6, and the spin base 6 and the chuck pins 7 as rotational axes. A spin motor 8 that rotates about A1. The plurality of chuck pins 7 are between a closed position where the plurality of chuck pins 7 hold the substrate W horizontally above the spin base 6 and an open position where the gripping of the substrate W by the plurality of chuck pins 7 is released. , Movable with respect to the spin base 6. Although not shown, the spin chuck 5 includes a chuck opening / closing mechanism that moves a plurality of chuck pins 7 between a closed position and an open position.

  The processing unit 2 includes a lower surface nozzle 9 that discharges the processing liquid toward the center of the lower surface of the substrate W. The processing unit 2 is further provided with a lower room temperature pure water pipe 10 that guides pure water (deionized water: Deionzied Water) at room temperature (for example, 20 to 30 ° C.) to the lower surface nozzle 9 and a lower room temperature pure water pipe 10. The lower room temperature pure water valve 11, the cold water pipe 12 for guiding cold water (pure water having a temperature lower than room temperature) lower than room temperature (for example, pure water lower than room temperature) to the lower surface nozzle 9, and the lower cold water pipe 12 It includes an intervening chilled water valve 13 and a cooler (not shown) that lowers the temperature of pure water supplied from the chilled water pipe 12 to the lower surface nozzle 9 to a temperature lower than room temperature.

  The processing unit 2 further includes a cylindrical lower gas flow path 15 formed by the outer peripheral surface of the lower surface nozzle 9 and the inner peripheral surface of the spin base 6, and a lower gas for introducing nitrogen gas at room temperature to the lower gas flow path 15. A pipe 16, a lower gas valve 17 interposed in the lower gas pipe 16, and a lower gas flow rate adjusting valve 18 that increases or decreases the flow rate of nitrogen gas supplied from the lower gas pipe 16 to the lower gas flow path 15. . The lower gas flow path 15 includes an annular upward discharge port 14 that opens at the center of the upper surface of the spin base 6.

  The processing unit 2 includes a chemical solution nozzle 19 that discharges SC-1 (an aqueous solution containing ammonia and hydrogen peroxide), which is an example of a chemical solution, a nozzle arm 20 having a chemical solution nozzle 19 attached to the tip, and a nozzle. And a chemical nozzle moving unit 21 that moves the chemical nozzle 19 between the processing position and the retracted position by moving the arm 20. The processing unit 2 further includes a chemical liquid pipe 22 that guides the chemical liquid to the chemical liquid nozzle 19 and a chemical liquid valve 23 interposed in the chemical liquid pipe 22. The processing position is a position where the processing liquid discharged from the chemical liquid nozzle 19 is deposited on any position within the upper surface of the substrate W. The retracted position is a position where the chemical nozzle 19 is retracted from above the substrate W.

  The processing unit 2 includes a pure water nozzle 24 for discharging pure water downward, a nozzle arm 25 to which the pure water nozzle 24 is attached at the tip, and a movement of the nozzle arm 25 to thereby change the processing position and the retreat position. And a pure water nozzle moving unit 26 for moving the pure water nozzle 24 therebetween. The processing unit 2 further includes a room temperature pure water pipe 27 that guides room temperature pure water to the pure water nozzle 24, a room temperature pure water valve 28 interposed in the room temperature pure water pipe 27, and a temperature lower than room temperature (for example, 0 .5 ° C.) cold water pipe 29 for introducing cold water to the pure water nozzle 24, a cold water valve 30 interposed in the cold water pipe 29, and the temperature of pure water supplied from the cold water pipe 29 to the pure water nozzle 24 from room temperature. And a cooler (not shown) for lowering the temperature to a lower temperature.

  The processing unit 2 includes a cooling gas nozzle 31 that discharges nitrogen gas having a temperature lower than the freezing point of water at one atmospheric pressure (for example, −100 to −20 ° C., specifically −150 ° C.) downward, and a cooling gas nozzle 31. A nozzle arm 32 attached to the tip portion and a cooling gas nozzle moving unit 33 for moving the cooling gas nozzle 31 between the processing position and the retracted position by moving the nozzle arm 32 are included. The processing unit 2 further includes a cooling gas pipe 34 for introducing a low-temperature nitrogen gas to the cooling gas nozzle 31, a cooling gas valve 35 interposed in the cooling gas pipe 34, and a gas supplied from the cooling gas pipe 34 to the cooling gas nozzle 31. A cooler (not shown) that lowers the temperature of water to a temperature lower than the freezing point of water, and a cooling gas flow rate adjustment valve 36 that increases or decreases the flow rate of nitrogen gas supplied from the cooling gas pipe 34 to the cooling gas nozzle 31. Including.

  The cup 37 can be moved up and down in the vertical direction between an upper position and a lower position. The upper position is a processing position where the upper end of the cup 37 is positioned above the holding position of the substrate W by the spin chuck 5. The lower position is a retracted position (position shown in FIG. 1) in which the upper end of the cup 37 is positioned below the holding position of the substrate W by the spin chuck 5. The processing unit 2 includes a cup elevating unit 38 that elevates and lowers the cup 37 between an upper position and a lower position. In a state where the cup 37 is positioned at the upper position, the processing liquid discharged from the substrate W to the periphery thereof is received by the cup 37 and collected in the cup 37. Then, the processing liquid collected in the cup 37 is recovered or discarded.

  The blocking plate 39 is supported in a horizontal posture by a support shaft 41 extending in the vertical direction along the rotation axis A1. The center line of the blocking plate 39 is disposed on the rotation axis A1. The blocking plate 39 includes a circular lower surface (opposing surface) whose outer diameter is larger than the diameter of the substrate W, and a downward discharge port 40 that opens at the center of the lower surface of the blocking plate 39. The blocking plate 39 is disposed below the support shaft 41. The support shaft 41 is supported by a support arm 42 that extends horizontally above the blocking plate 39.

  The processing unit 2 includes a blocking plate lifting / lowering unit 43 that lifts and lowers the blocking plate 39. The blocking plate lifting / lowering unit 43 moves the support arm 42 in the vertical direction, so that the lower surface of the blocking plate 39 is lowered to the height at which the scan nozzle such as the chemical solution nozzle 19 cannot enter between the substrate W and the blocking plate 39. The blocking plate 39 is moved up and down between a proximity position close to the upper surface and a retracted position (position shown in FIG. 1) above the proximity position. The blocking plate lifting / lowering unit 43 can position the blocking plate 39 at an arbitrary position (height) from the lower position to the upper position.

  The processing unit 2 includes an upper surface nozzle 44 that discharges the processing liquid downward via a downward discharge port 40 that opens at the center of the lower surface of the blocking plate 39. The processing unit 2 further includes an upper hot water pipe 45 that guides hot water (pure water having a temperature higher than normal temperature) having a temperature higher than normal temperature (for example, 50 to 90 ° C .; specifically, 80 ° C.) to the upper surface nozzle 44; An upper hot water valve 46 interposed in the hot water pipe 45, a heater (not shown) for raising the temperature of pure water supplied from the upper hot water pipe 45 to the upper surface nozzle 44 to a temperature higher than normal temperature, and a rinse liquid An upper rinse liquid pipe 47 that guides the liquid to the upper surface nozzle 44, and an upper rinse liquid valve 48 interposed in the upper rinse liquid pipe 47.

The processing unit 2 includes a cylindrical upper gas passage 49 formed by the outer peripheral surface of the upper surface nozzle 44 and the inner peripheral surface of the blocking plate 39, and an upper gas pipe 50 that guides nitrogen gas at room temperature to the upper gas passage 49. And an upper gas valve 51 interposed in the upper gas pipe 50. The upper gas flow path 49 is disposed above the downward discharge port 40 that opens on the opposing surface of the blocking plate 39.
FIG. 2 is a process diagram illustrating an example of a processing method performed by the processing unit 2. FIG. 3 is a schematic diagram illustrating a state of the substrate W when the process illustrated in FIG. 2 is performed. In the following, reference is made to FIG. 1 and FIG. Reference is made to FIG. 3 as appropriate.

When the substrate W is processed by the processing unit 2, a loading process (step S <b> 1 in FIG. 2) for loading the substrate W into the processing unit 2 is performed.
Specifically, the control device 3 opens the lower gas valve 17 and starts discharging nitrogen gas at the first flow rate (for example, 50 L / min) to the upward discharge port 14 of the spin base 6. Thereafter, the control device 3 controls the transport robot so that the substrate W held by the hand of the transport robot is placed on the plurality of chuck pins 7 in a state where the blocking plate 39 and the like are retracted. In addition, after the substrate W is placed on the plurality of chuck pins 7, the control device 3 causes the plurality of chuck pins 7 to grip the substrate W and retracts the hand of the transfer robot from the chamber 4.

Next, a chemical supply process (step S2 in FIG. 2) for supplying SC-1 as an example of the chemical to the upper surface of the substrate W is performed.
Specifically, the control device 3 causes the spin motor 8 to start rotating the substrate W so that the substrate W rotates at a liquid processing speed (for example, 800 rpm), and the chemical nozzle 19 is moved from the retracted position to the processing position. The chemical solution nozzle moving unit 21 is controlled to move. Thereafter, the control device 3 opens the chemical liquid valve 23 and causes the chemical liquid nozzle 19 to start discharging SC-1. Thereby, SC-1 is supplied to the entire upper surface of the substrate W, and an SC-1 liquid film covering the entire upper surface of the substrate W is formed on the substrate W. When a predetermined time elapses after the chemical liquid valve 23 is opened, the control device 3 closes the chemical liquid valve 23 and causes the chemical nozzle 19 to finish discharging SC-1. Thereafter, the control device 3 moves the chemical nozzle 19 to the retracted position. While the chemical nozzle 19 is discharging SC-1, the control device 3 may stop the SC-1 liquid landing position on the upper surface of the substrate W at the central portion, or between the central portion and the peripheral portion. You may move it with.

Next, an upper surface rinsing liquid supply step (step S3 in FIG. 2) for supplying room temperature pure water, which is an example of a rinsing liquid, to the upper surface of the substrate W, and a lower surface of the substrate W, which is an example of a rinsing liquid, The lower surface rinsing liquid supply step (step S3 in FIG. 2) to be supplied to is performed in parallel.
Regarding the upper surface rinsing liquid supply step, the control device 3 controls the pure water nozzle moving unit 26 so that the pure water nozzle 24 moves from the retracted position to the processing position. Thereafter, the control device 3 opens the normal temperature pure water valve 28 and causes the pure water nozzle 24 to start discharging normal temperature pure water. Thereby, SC-1 adhering to the upper surface of the substrate W is washed away with pure water, and the entire upper surface of the substrate W is covered with a liquid film of pure water. When a predetermined time elapses after the room temperature pure water valve 28 is opened, the control device 3 closes the room temperature pure water valve 28 and causes the pure water nozzle 24 to finish discharging pure water.

  Regarding the lower surface rinsing liquid supply step, the control device 3 opens the lower room temperature pure water valve 11 and causes the lower surface nozzle 9 to start discharging normal temperature pure water. Thereby, the SC-1 mist and the like adhering to the lower surface of the substrate W are washed away with pure water. When a predetermined time elapses after the lower normal temperature valve is opened, the control device 3 closes the lower normal temperature pure water valve 11 and causes the lower surface nozzle 9 to finish discharging pure water. The control device 3 opens and closes the lower room temperature pure water valve 11 so that the lower surface nozzle 9 discharges pure water during at least a part of the period during which the pure water nozzle 24 discharges pure water.

Next, a liquid film forming step (step S4 in FIG. 2) for supplying cold water, which is an example of a liquid to be solidified, to the upper surface of the substrate W, and cold water, which is an example of a low-temperature liquid lower than room temperature, are applied to the lower surface of the substrate W. The liquid supply process to supply (step S4 in FIG. 2) is performed in parallel.
Regarding the liquid film forming step, the control device 3 controls the spin motor 8 so that the substrate W rotates at a liquid film forming speed (for example, 150 rpm) smaller than the liquid processing speed. Furthermore, the control device 3 opens the cold water valve 30 and causes the pure water nozzle 24 located at the processing position to start discharging cold water. When a predetermined time elapses after the cold water valve 30 is opened, the control device 3 closes the cold water valve 30 and causes the pure water nozzle 24 to finish discharging pure water. Thereafter, the control device 3 moves the pure water nozzle 24 to the retracted position.

  Regarding the liquid supply process, the control device 3 opens the lower chilled water valve 13 in a state where the upward discharge port 14 is discharging nitrogen gas at the first flow rate, and causes the lower surface nozzle 9 to start discharging chilled water. When a predetermined time elapses after the lower chilled water valve 13 is opened, the control device 3 closes the lower chilled water valve and causes the lower surface nozzle 9 to finish discharging pure water. The control device 3 opens and closes the chilled water valve 13 so that the lower surface nozzle 9 discharges pure water during at least a part of the period during which the pure water nozzle 24 discharges pure water.

  The cold water discharged from the pure water nozzle 24 is supplied to the entire upper surface of the substrate W. Similarly, the cold water discharged from the lower surface nozzle 9 is supplied to the entire lower surface of the substrate W. Thereby, the substrate W is cooled by the cold water, and the temperature of the substrate W approaches the temperature of the cold water. The cold water discharged from the pure water nozzle 24 forms a liquid film that covers the entire upper surface of the substrate W. At this time, the thickness of the liquid film of the cold water is adjusted to a size depending on a plurality of factors (such as the rotation speed of the substrate W, the surface tension of the liquid, and the surface state of the substrate W (whether it is hydrophobic)). The thickness of the cold water liquid film covering the entire upper surface of the substrate W is, for example, 50 μm in the region inside the outer peripheral portion of the liquid film.

  Next, freezing that freezes the liquid film of pure water covering the upper surface of the substrate W by discharging low-temperature nitrogen gas, which is an example of a cooling gas having a temperature lower than the freezing point of the solidification target liquid, toward the upper surface of the substrate W. A liquid film of pure water that covers the upper surface of the substrate W by evaporating the liquid adhering to the lower surface of the substrate W by supplying nitrogen gas at room temperature to the lower surface of the substrate W by supplying a process (step S5 in FIG. 2). The gas supply step (step S5 in FIG. 2) that promotes or assists freezing is performed in parallel.

  Regarding the freezing process, the control device 3 controls the spin motor 8 so that the substrate W rotates at a freezing speed (for example, 50 rpm) smaller than the liquid film forming speed. Further, the control device 3 controls the cooling gas nozzle moving unit 33 so that the cooling gas nozzle 31 moves from the retracted position to the processing position. Thereafter, the control device 3 opens the cooling gas valve 35 and causes the cooling gas nozzle 31 to start discharging low temperature nitrogen gas. Then, the control device 3 moves the cooling gas nozzle 31 outwardly (in a direction away from the rotation axis A1) while the cooling gas nozzle 31 is discharging low-temperature nitrogen gas toward the upper surface of the substrate W. Thereby, the frozen part of the liquid film spreads outward, and the entire liquid film freezes. After the liquid film on the substrate W has changed to a frozen film, the control device 3 closes the cooling gas valve 35 and causes the cooling gas nozzle 31 to finish discharging low temperature nitrogen gas. Thereafter, the control device 3 moves the cooling gas nozzle 31 to the retracted position.

  Regarding the gas supply process, the control device 3 adjusts the lower gas flow rate so that the discharge flow rate of nitrogen gas from the upward discharge port 14 increases to a second flow rate (for example, 100 L / min) larger than the first flow rate. The opening degree of the valve 18 is increased. And the control apparatus 3 starts the reduction | decrease of the discharge flow rate of the nitrogen gas from the upward discharge port 14 during the period when the cooling gas nozzle 31 is discharging low temperature nitrogen gas. At this time, the control device 3 decreases the opening degree of the lower gas flow rate adjustment valve 18 so that the discharge flow rate of nitrogen gas from the upward discharge port 14 decreases from the second flow rate to the first flow rate.

  The increase in the nitrogen gas discharge flow rate is preferably started simultaneously with the start of the discharge of the low-temperature nitrogen gas or before the start of the discharge of the low-temperature nitrogen gas. It may be started after it has been started. Further, the decrease in the discharge flow rate of the nitrogen gas is preferably terminated during the period in which the cooling gas nozzle 31 is discharging low-temperature nitrogen gas, but the decrease in the period in which the cooling gas nozzle 31 is discharging low-temperature nitrogen gas. It may be terminated later.

  Nitrogen gas discharged from the upward discharge port 14 is supplied to the lower surface of the substrate W. As shown in FIG. 3, the lower surface of the substrate W is wet with pure water supplied in the liquid supply process. Evaporation of the pure water on the lower surface of the substrate W is promoted by supplying nitrogen gas. In particular, since the discharge flow rate of nitrogen gas from the upward discharge port 14 is increased to the second flow rate, evaporation of pure water is further promoted. The substrate W is cooled as the pure water on the lower surface of the substrate W evaporates. Thereby, the temperature of the frozen film formed by freezing the liquid film can be lowered. Alternatively, the entire liquid film on the substrate W can be frozen in a shorter time. In this way, freezing of the liquid film of pure water covering the upper surface of the substrate W is promoted or assisted.

Next, a frozen film removing step (FIG. 5) of thawing and removing the frozen film on the substrate W by discharging hot water, which is an example of a thawing solution having a temperature higher than the freezing point of the liquid to be solidified, toward the upper surface of the substrate W. Step S6) of 2 is performed.
Specifically, the control device 3 controls the spin motor 8 so that the substrate W rotates at a frozen film removal speed (for example, 2000 rpm) larger than the freezing speed. Further, the control device 3 opens the upper gas valve 51 to start the discharge of nitrogen gas to the downward discharge port 40 of the blocking plate 39. Further, the control device 3 controls the shielding plate lifting / lowering unit 43 so that the shielding plate 39 moves from the retracted position to the processing position. Thereafter, the control device 3 opens the upper hot water valve 46 and causes the upper surface nozzle 44 to start discharging hot water. The frozen film on the substrate W is thawed by supplying hot water and discharged from the substrate W to the periphery thereof. Thereby, the entire upper surface of the substrate W is covered with hot water. When a predetermined time elapses after the upper hot water valve 46 is opened, the control device 3 closes the upper hot water valve 46 and causes the upper surface nozzle 44 to finish discharging hot water.

Next, a final rinsing liquid supply step (step S7 in FIG. 2) for supplying pure water at room temperature, which is an example of a rinsing liquid, to the upper surface of the substrate W is performed.
Specifically, the control device 3 controls the spin motor 8 so that the substrate W rotates at a final rinse speed (for example, 500 rpm) smaller than the frozen film removal speed. Thereafter, the control device 3 opens the upper rinse liquid valve 48 in a state where the blocking plate 39 is located at the processing position, and causes the upper surface nozzle 44 to start discharging pure water at room temperature. As a result, the pure water liquid film on the substrate W is replaced with the pure water discharged from the upper surface nozzle 44, and a pure water liquid film covering the entire upper surface of the substrate W is formed. When a predetermined time elapses after the upper rinse liquid valve 48 is opened, the control device 3 closes the upper rinse liquid valve 48 and causes the upper surface nozzle 44 to finish discharging pure water.

Next, a drying process (step S8 in FIG. 2) for drying the substrate W by high-speed rotation of the substrate W is performed.
Specifically, the control device 3 has a drying speed (for example, higher than the final rinse speed) in a state where the blocking plate 39 is close to the upper surface of the substrate W and the downward discharge port 40 is discharging nitrogen gas. The spin motor 8 is controlled so that the substrate W rotates at 2500 rpm. Thereby, a large centrifugal force is applied to the liquid adhering to the substrate W, and the liquid is shaken off from the substrate W to the periphery thereof. Therefore, the liquid is removed from the substrate W, and the substrate W is dried. When a predetermined time elapses after the high-speed rotation of the substrate W is started, the control device 3 causes the spin motor 8 to stop the rotation of the substrate W.

Next, an unloading step (Step S9 in FIG. 2) for unloading the substrate W from the processing unit 2 is performed.
Specifically, the control device 3 controls the shield plate lifting / lowering unit 43 so that the shield plate 39 moves to the retracted position. Further, the control device 3 closes the upper gas valve 51 and the lower gas valve 17 to end the discharge of nitrogen gas from the downward discharge port 40 and the upward discharge port 14. Further, the control device 3 causes the plurality of chuck pins 7 to release the grip of the substrate W. In this state, the control device 3 causes the hand of the transfer robot to enter the chamber 4. Then, the control device 3 holds the substrate W on the plurality of chuck pins 7 in the hand of the transfer robot. Thereafter, the control device 3 and the hand of the transfer robot are retracted from the chamber 4. Thereby, the processed substrate W is unloaded from the chamber 4.

  As described above, in this embodiment, the liquid is supplied to the lower surface of the substrate W before the liquid film covering the upper surface of the substrate W is frozen. Thereafter, as shown in FIG. 3, a gas as an evaporation promoting gas is supplied to the lower surface of the substrate W in parallel with freezing the liquid film. Since the lower surface of the substrate W is wet, when gas is supplied to the lower surface of the substrate W, the liquid on the lower surface of the substrate W evaporates and the heat of the substrate W is absorbed by the liquid as heat of vaporization. Therefore, the substrate W is cooled while the liquid film is frozen. Thereby, the liquid film covering the upper surface of the substrate W can be efficiently frozen. Therefore, the temperature of the frozen film formed by freezing the liquid film can be lowered. Alternatively, the entire liquid film on the substrate W can be frozen in a shorter time. The particle removal rate increases as the temperature of the frozen film decreases. Therefore, the particle removal rate can be increased. Further, if the liquid film is frozen in a shorter time, the consumption amount of the cooling gas can be reduced, so that the cost required for processing the substrate W can be reduced.

  In the present embodiment, a large flow of gas is supplied to the lower surface of the substrate W during the period in which the liquid film is frozen. Thereby, the evaporation of the liquid on the lower surface of the substrate W is further promoted. Thereby, the liquid film covering the upper surface of the substrate W can be efficiently frozen. Moreover, since gas is not always supplied with a large flow rate, but the gas flow rate is temporarily increased, an increase in gas consumption can be suppressed. Thereby, an increase in cost required for processing the substrate W can be suppressed.

In the present embodiment, a normal temperature gas is supplied to the lower surface of the substrate W during the period in which the liquid film is frozen. Therefore, it is not necessary to adjust the temperature of the gas supplied to the lower surface of the substrate W. Therefore, the cost required for adjusting the gas temperature can be reduced. Thereby, the cost required for processing the substrate W can be reduced.
In the present embodiment, in the liquid supply process (step S4), a liquid having a temperature lower than normal temperature is supplied to the lower surface of the substrate W. Thereby, the substrate W and the liquid film are cooled. Or the temperature rise of the board | substrate W and a liquid film is suppressed. Therefore, the liquid film covering the upper surface of the substrate W can be efficiently frozen.

Although the description of the embodiment of the present invention has been described above, the present invention is not limited to the contents of the above-described embodiment, and various modifications can be made within the scope of the present invention.
For example, in the above-described embodiment, the case where cold water (pure water having a temperature lower than normal temperature) is supplied to the lower surface of the substrate W in the liquid supply process has been described. However, a volatile solvent (for example, IPA) having higher volatility than water has been described. ) May be supplied to the lower surface of the substrate W in the liquid supply step. In this case, since the liquid adhering to the lower surface of the substrate W is easily evaporated, the substrate W can be efficiently cooled. Moreover, instead of cold water, room-temperature pure water may be supplied to the lower surface of the substrate W.

  In the above-described embodiment, the case where the normal temperature nitrogen gas is supplied to the lower surface of the substrate W in the gas supply process has been described. However, the nitrogen gas is lower than the normal temperature and higher than the freezing point of the liquid on the lower surface of the substrate W May be supplied to the lower surface of the substrate W. In this case, the substrate W is cooled by evaporation of pure water, and the substrate W is cooled by the nitrogen gas supplied to the lower surface of the substrate W, so that the temperature of the frozen film can be further lowered. Alternatively, the entire liquid film on the substrate W can be frozen in a shorter time.

  In the above-described embodiment, the case where the chemical solution is SC-1 has been described. However, the chemical solution is sulfuric acid, acetic acid, nitric acid, hydrochloric acid, hydrofluoric acid, aqueous ammonia, hydrogen peroxide solution, organic acid (for example, citric acid, oxalic acid). Etc.), an organic alkali (for example, TMAH: tetramethylammonium hydroxide, etc.), a surfactant, and a liquid containing at least one of a corrosion inhibitor.

In the above-described embodiment, the case where the rinse liquid is pure water has been described. However, the rinse liquid is carbonated water, electrolytic ion water, hydrogen water, ozone water, IPA (isopropyl alcohol), and dilution concentration (for example, 10 Or about 100 ppm of hydrochloric acid water. IPA is an example of a volatile solvent that is more volatile than water.
Moreover, although the above-mentioned embodiment demonstrated the case where the pure water nozzle 24 discharges the pure water and cold water of normal temperature, the nozzle for exclusive use which discharges the cold water which is an example of the coagulation target liquid (coagulation target liquid nozzle) May be provided. In this case, the coagulation target liquid nozzle may be attached to a dedicated nozzle arm, or may be attached to a nozzle arm for another nozzle.

  Further, two or more of all the embodiments described above may be combined.

1: Substrate processing device 3: Control device (control means)
5: Spin chuck (substrate holding means)
9: Bottom nozzle (liquid supply means)
11: Lower room temperature pure water valve (liquid supply means)
13: Sewage water valve (liquid supply means)
14: Upward discharge port (gas supply means)
17: Lower gas valve (gas supply means)
18: Lower gas flow rate adjustment valve (gas supply means)
24: Pure water nozzle (liquid film forming means)
28: Room temperature pure water valve (liquid film forming means)
30: Cold water valve (liquid film forming means)
31: Cooling gas nozzle (freezing means)
35: Cooling gas valve (freezing means)
36: Cooling gas flow rate adjustment valve (freezing means)
W: Substrate

Claims (6)

A liquid film forming step of forming a liquid film covering the upper surface of the substrate;
A freezing step of freezing the liquid film after the liquid film forming step;
A liquid supplying step of wetting the lower surface of the substrate by supplying liquid to the lower surface of the substrate before the freezing step is started;
In parallel with the freezing step, a gas supply step of evaporating the liquid on the lower surface of the substrate by supplying gas to the lower surface of the substrate, and a substrate processing method. The liquid supply step includes a step of wetting the lower surface of the substrate by supplying liquid to the lower surface of the substrate while supplying gas to the lower surface of the substrate before the freezing step is started,
The gas supply step evaporates the liquid on the lower surface of the substrate by supplying the gas to the lower surface of the substrate at a supply flow rate larger than the gas supply flow rate in the liquid supply step in parallel with the freezing step. The substrate processing method of Claim 1 including a process.   The substrate processing method according to claim 1, wherein the gas supplied to the lower surface of the substrate in the gas supply step is a room temperature gas.   The substrate processing method according to claim 1, wherein the liquid supplied to the lower surface of the substrate in the liquid supply step is a liquid having a temperature lower than room temperature. The substrate processing method according to claim 1, wherein the liquid supplied to the lower surface of the substrate in the liquid supply step is a liquid having higher volatility than water. Substrate holding means for holding the substrate;
A liquid film forming means for forming a liquid film covering an upper surface of the substrate held by the substrate holding means;
Freezing means for freezing the liquid film;
Liquid supply means for wetting the lower surface of the substrate by supplying liquid to the lower surface of the substrate held by the substrate holding means;
Gas supply means for evaporating the liquid on the lower surface of the substrate by supplying gas to the lower surface of the substrate held by the substrate holding means;
Control means for controlling the liquid film forming means, freezing means, liquid supply means, and gas supply means,
The control means includes
A liquid film forming step of forming a liquid film covering the upper surface of the substrate;
A freezing step of freezing the liquid film after the liquid film forming step;
A liquid supplying step of wetting the lower surface of the substrate by supplying liquid to the lower surface of the substrate before the freezing step is started;
In parallel with the freezing step, a gas supply step of evaporating liquid on the lower surface of the substrate by supplying gas to the lower surface of the substrate is performed.

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