JP2006278955A - Method and device for substrate processing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for substrate processing which can control the consumption volume of a processing liquid regardless of a state of a substrate; and to provide a device for substrate processing. <P>SOLUTION: A substrate W to be treated is held by a spin chuck 1 and is contained in a sealable processing chamber 12. The pressure of space in the processing chamber 12 can be reduced by a gas suction mechanism 17 through an exhaust/suction passage 13, a three way valve 14, and an exhaust passage 16. When a chemical liquid processing step is carried out by supplying a chemical liquid from a chemical liquid nozzle 2 to the substrate W, the inside of the processing chamber 12 becomes a state of reduced pressure. The whole surface of the substrate W can be covered by a little chemical liquid, even if the surface of the substrate W is a hydrophobic surface because the wettability for the processing liquid of the substrate W is good in a state of reduced pressure. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a substrate processing method and a substrate processing apparatus for processing a substrate by supplying a processing liquid (chemical solution or pure water) to the substrate. Substrates to be processed include, for example, semiconductor wafers, glass substrates for liquid crystal display devices, glass substrates for plasma displays, optical disk substrates, magnetic disk substrates, magneto-optical disk substrates, photomask substrates, and the like. .

In a manufacturing process of a semiconductor device, a substrate processing apparatus that performs processing using a processing liquid on a semiconductor substrate (semiconductor wafer) is used. A single-wafer type substrate processing apparatus that processes substrates one by one is a spin chuck that rotates while holding the substrate almost horizontally, and a processing liquid (chemical solution or pure water) to the substrate held by the spin chuck. And a treatment liquid nozzle to be supplied.
When a substrate is processed with a chemical solution, the spin chuck is rotated while the chemical solution is continuously discharged from the processing solution nozzle, and the substrate surface is processed while forming a flow of the chemical solution on the spin chuck (continuous) Discharge processing) has been performed conventionally. As another method, while the spin chuck is stopped or rotated at a very low speed, the processing liquid is supplied from the processing liquid nozzle to the substrate surface and accumulated on the surface, and the liquid film is held on the substrate surface. A liquid piling process (paddle process) for advancing the process is known. By using this method, the consumption of the chemical solution can be reduced.
JP 2001-237214 A

In recent years, along with miniaturization of patterns formed on substrates and higher performance of devices, miniaturization of hole diameters formed in films on substrates and changes in film types have been proposed and implemented. . Along with this, the surface of the substrate (the surface of the thin film formed on the substrate) is sometimes in a hydrophobic state.
If the surface of the substrate is in a hydrophobic state, it becomes difficult to cover the entire surface of the substrate with the processing liquid, which may cause in-plane non-uniformity of the processing.

Therefore, when performing continuous ejection processing, the processing liquid is continuously supplied onto the substrate at a large flow rate so as to cover the entire surface of the substrate, but this increases the consumption of the processing liquid. ing.
In addition, in the case of performing the liquid deposition process, the processing liquid is supplied until a liquid film covering the entire surface of the substrate is formed. However, the amount of processing liquid required for this is increased.

As described above, in the prior art, a large amount of processing liquid is required when processing a substrate in a hydrophobic state, which increases the substrate processing cost.
SUMMARY OF THE INVENTION An object of the present invention is to provide a substrate processing method and a substrate processing apparatus that can suppress the consumption of processing liquid regardless of the state of the substrate.

  The invention according to claim 1 for achieving the above object includes a substrate holding step of holding the substrate (W) by the substrate holding mechanism (1), and being held by the substrate holding mechanism during the substrate holding step. A processing liquid supply step for supplying the processing liquid to the substrate being held, and a space containing the substrate held by the substrate holding mechanism is held in a reduced pressure state below a predetermined atmospheric pressure below atmospheric pressure during the processing liquid supply step. And a decompression step. The alphanumeric characters in parentheses indicate corresponding components in the embodiments described later. The same applies hereinafter.

  According to this method, when the processing liquid is supplied to the substrate held by the substrate holding mechanism, the space including the substrate is equal to or lower than a predetermined atmospheric pressure (for example, 930 hPa or lower, more preferably 500 hPa or lower, lower than atmospheric pressure). The pressure is preferably reduced to 300 hPa or less, most preferably 30 hPa or less. As a result of verification by the inventor, the apparent contact angle of the treatment liquid with respect to the substrate is reduced in the reduced pressure space of the predetermined atmospheric pressure or less, and even when the substrate surface is a hydrophobic surface, the treatment liquid is Good wettability with respect to the substrate surface. Based on such knowledge, the present invention supplies the processing liquid to the substrate under a reduced pressure environment, so that even if the substrate surface is a hydrophobic surface, the entire surface of the substrate surface can be covered with a small amount of processing liquid. It is possible to cover. As a result, the consumption of the processing liquid can be suppressed regardless of the state of the substrate.

  Furthermore, the cost of substrate processing can be reduced by reducing the amount of processing liquid used. Further, in the case where the processing liquid supplied to the substrate is collected and reused, the amount of the processing liquid exposed to the air is reduced, so that the life of the processing liquid can be extended, and the result is also the result. As a result, the amount of processing solution used is reduced. Thereby, cost reduction can be expected.

Furthermore, mist generated from the processing liquid can be reduced by reducing the amount of the processing liquid used. This can reduce or prevent defects due to mist reattaching to the surface of the substrate.
Furthermore, since the wettability of the substrate with respect to the processing liquid is improved, the processing liquid can be distributed between minute patterns formed on the substrate or in minute holes. As a result, the substrate surface can be processed with the treatment liquid all over, and for example, when cleaning the substrate surface with the treatment liquid, an improvement in cleaning efficiency can be expected.

A second aspect of the present invention is the substrate processing method according to the first aspect, wherein the processing liquid contains a chemical solution or pure water.
Under the reduced pressure environment as described above, even when the substrate surface is a hydrophobic surface, the substrate surface exhibits good wettability with respect to both chemicals and pure water. Therefore, even when the treatment liquid contains either a chemical solution or pure water, the above-described effects can be obtained.

  In particular, when both chemical and pure water are used as the treatment liquid, the chemical solution is first supplied to the substrate surface to perform the chemical treatment process, and then the supply of the chemical solution is stopped and pure water is supplied to the substrate surface instead. The pure water supply process can be performed. In this case, a rinsing process for replacing the chemical solution on the substrate with pure water is performed by supplying pure water. However, since the substrate exhibits good wettability with respect to pure water, The entire surface of the substrate can be cleaned. Of course, pure water for cleaning also enters between minute patterns on the substrate and into minute holes, so that excellent rinsing efficiency can be obtained.

According to a third aspect of the present invention, the substrate is held horizontally by the substrate holding mechanism, a processing liquid is deposited on the surface of the horizontally held substrate, and a liquid film of the processing liquid is held. The substrate processing method according to claim 1, further comprising a liquid filling step of processing the surface of the substrate with a processing liquid to be formed.
In this method, the substrate is held horizontally, and the processing liquid is deposited on the surface of the substrate. By performing such a liquid accumulation process in a reduced pressure space of the predetermined atmospheric pressure or less, if a small amount of processing liquid is supplied onto the substrate, a liquid film covering the entire surface of the substrate can be easily formed by this processing liquid. can do. In this way, since the amount of processing liquid required for the liquid accumulation process can be reduced, the substrate processing cost can be reduced. In addition, even when the used processing liquid is collected and reused, the amount of processing liquid exposed to the atmosphere can be reduced, so that the life of the processing liquid can be extended, thereby reducing costs. Can be realized.

In the case where a substrate holding and rotating mechanism is used as the substrate holding mechanism, in the liquid filling step, the rotation of the substrate by the substrate holding and rotating mechanism may be stopped, and the liquid film is broken by the substrate holding and rotating mechanism. It is good also as rotating a board | substrate in the low-speed rotation state which is not.
According to a fourth aspect of the present invention, the substrate holding mechanism is a substrate holding and rotating mechanism capable of holding and rotating a substrate, which is performed in parallel with the decompression step after the processing with the processing liquid, 4. The substrate processing method according to claim 1, further comprising a drying step of rotating the substrate by a holding and rotating mechanism to remove the processing liquid on the surface of the substrate.

  In this method, even in a drying process in which the substrate is rotated and the processing liquid on the substrate surface is removed by centrifugal force, the substrate is placed in a reduced-pressure atmosphere of the predetermined atmospheric pressure or less. Thereby, since the drying process is performed in an atmosphere with a reduced oxygen concentration, the generation of so-called watermarks on the substrate surface can be suppressed or prevented, and a favorable drying process can be realized.

According to a fifth aspect of the present invention, the substrate holding mechanism is accommodated in a process chamber (12) that can be sealed, and the decompression step places the process chamber in a sealed state and exhausts the internal space of the process chamber. The substrate processing method according to claim 1, further comprising a step of reducing the pressure.
In this method, the processing chamber is hermetically sealed, and the space including the substrate held by the substrate holding mechanism can be reduced to the predetermined atmospheric pressure or less by exhausting the internal space of the processing chamber.

  According to a sixth aspect of the present invention, the substrate holding mechanism includes a base member (25) facing one surface of the substrate, and the pressure reducing step is performed on the base member from the other surface side of the substrate by a lid member (51). The method includes: housing the substrate in a sealed space (50) sealed by the base member and the lid member, and evacuating and reducing the pressure of the sealed space. Item 5. The substrate processing method according to any one of Items 1 to 4.

In this method, a sealed space surrounding the substrate can be formed by the base member provided in the substrate holding mechanism and the lid member in close contact with the base member, and the sealed space is decompressed to the predetermined pressure or less. . As a result, the volume of the space that needs to be depressurized is reduced, so that the control of the atmospheric pressure in the space where the substrate is placed is facilitated.
The invention according to claim 7 is a substrate holding mechanism (1) for holding the substrate (W) and a processing liquid supply mechanism (2-9, 58-) for supplying a processing liquid to the substrate held by the substrate holding mechanism. 60) and a pressure reducing mechanism (13, 16, 17) for reducing the space including the substrate held by the substrate holding mechanism to a predetermined atmospheric pressure lower than the atmospheric pressure. is there.

  With this configuration, the substrate can be processed with the processing liquid in the reduced pressure space of the predetermined atmospheric pressure or less. As a result, the apparent contact angle of the processing liquid with respect to the substrate surface decreases, and the substrate exhibits good wettability with respect to the processing liquid. Thereby, even if the substrate surface is a hydrophobic surface, the substrate treatment with the treatment liquid can be performed satisfactorily. Furthermore, since the necessary amount of processing liquid can be reduced, the substrate processing cost can be reduced. In addition, since the amount of processing liquid to be used can be reduced, mist generated from the processing liquid can be reduced. Therefore, it is possible to suppress or prevent such mist from re-adhering to the surface of the substrate. Can be improved.

The processing liquid supply mechanism may include a chemical liquid supply mechanism (2, 4, 5, 6, 58 to 60) for supplying a chemical liquid as the processing liquid. The processing liquid supply mechanism may include a pure water supply mechanism (3, 7, 8, 9, 58 to 60) for supplying pure water as the processing liquid.
The substrate holding mechanism may be accommodated in a processing chamber that surrounds the substrate holding mechanism and can be sealed. In this case, the pressure reducing mechanism may exhaust the internal space of the processing chamber to reduce the pressure below the predetermined atmospheric pressure.

  The substrate holding mechanism may include a base member (25) facing one surface of the substrate. In this case, a sealed space (50) is formed in close contact with the base member from the other surface side of the substrate, and a lid member (51) for accommodating the substrate is further provided in the sealed space. It is preferable. In the case of this configuration, it is preferable that the pressure reducing mechanism exhausts the inside of a sealed space formed by the base member and the lid member to reduce the pressure below the predetermined atmospheric pressure.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is an illustrative view showing a basic configuration of a substrate processing apparatus according to a first embodiment of the present invention. This substrate processing apparatus is a single wafer type apparatus that processes substrates one by one, and includes a spin chuck 1 that holds a single substrate W in a substantially horizontal posture and rotates it around a vertical axis. Further, the substrate processing apparatus includes a chemical nozzle 2 that supplies a chemical liquid as a processing liquid toward the vicinity of the rotation center of the surface of the substrate W held on the spin chuck 1, and an upper surface of the substrate W held on the spin chuck 1. And a pure water nozzle 3 for supplying pure water (deionized water) as a treatment liquid toward the vicinity of the rotation center of the water. A chemical liquid from a chemical liquid supply source 4 is supplied to the chemical liquid nozzle 2 via a chemical liquid supply path 5, and a chemical liquid valve 6 for switching supply / stop of the chemical liquid is interposed in the chemical liquid supply path 5. Yes. Similarly, pure water from a pure water supply source 7 is supplied to the pure water nozzle 3 via a pure water supply path 8, and the pure water supply path 8 is a pure water that switches between supply and stop of pure water. A water valve 9 is interposed.

  The spin chuck 1 is accommodated in a processing cup 11 that receives a processing liquid that scatters around during liquid processing. Further, the processing cup 11 has an openable / closable substrate loading / unloading port (not shown) for loading and unloading the substrate W, and is accommodated in a processing chamber 12 capable of forming a sealed space inside. . The internal space of the processing chamber 12 can be exhausted through the exhaust / air supply path 13 and can introduce an external gas (inert gas such as nitrogen gas or clean air). More specifically, a three-way valve 14 is interposed in the exhaust / air supply path 13, and the three-way valve 14 is configured to connect the exhaust / air supply path 13 to either the gas introduction path 15 or the exhaust path 16. It is switched to connect to The gas introduction path 15 communicates with the space in the clean room in which the substrate processing apparatus is arranged, and may introduce clean air in the clean room. It may be connected to a gas supply source such as an air supply source. The exhaust path 16 is connected to a gas suction mechanism 17 such as a vacuum pump.

  On the other hand, the atmosphere inside the processing cup 11 is exhausted from below through the exhaust path 20. As a result, an atmosphere can be taken into the processing cup 11 from the opening on the upper surface and a downward flow can be formed downward, and the atmosphere containing the mist of the processing liquid generated in the processing cup 11 is exhausted through the exhaust passage 20. Can be exhausted through. The exhaust path 20 is connected to an exhaust facility 21 such as an exhaust utility in a factory where the substrate processing apparatus is installed. An opening / closing mechanism 22 such as a damper for opening / closing the exhaust passage 20 is provided at the inlet of the exhaust passage 20.

  The spin chuck 1 supports a substantially disc-shaped spin base 25 facing the lower surface of the substrate W, a plurality of chuck pins 26 erected on the upper surface of the spin base 25, and the spin base 25 in a substantially horizontal posture. And a rotation drive mechanism (motor) 28 that applies a rotational force to the rotation shaft 27. The rotating shaft 27 is disposed along the vertical direction, and the spin base 25 is fixed substantially horizontally at the upper end thereof. The plurality of chuck pins 26 erected on the upper surface of the spin base 25 can come into contact with the end surface of the substrate W, and can sandwich the substrate W. Therefore, when the rotation shaft 27 is rotated around the vertical axis by the rotation drive mechanism 28, the substrate W is rotated around the vertical axis while maintaining the horizontal posture.

  In this embodiment, the rotary shaft 27 is a hollow shaft, and the lower surface treatment liquid supply pipe 30 is inserted into the rotary shaft 27. The upper end of the lower surface processing liquid supply pipe passes through the spin base 25 and faces the rotation center of the lower surface of the substrate W, and forms a lower surface processing liquid nozzle 31 that discharges the processing liquid toward the rotation center. Yes. Pure water as a treatment liquid is supplied to the lower surface treatment liquid supply pipe 30 from a pure water supply source 32 through a pure water supply path 33, and pure water is supplied to the pure water supply path 33. A deionized water valve 34 for switching between supply and stop is provided.

  The chemical solution supply source 4 includes a chemical solution tank 40 that stores the chemical solution, and a chemical solution pump 41 that pumps the chemical solution from the chemical solution tank 40 and sends it out to the chemical solution supply path 5. A chemical recovery path 10 is provided between the processing cup 11 and the chemical tank 40, and the chemical liquid after being used for processing the substrate W is transferred to the chemical tank 40 via the chemical recovery path 10. It is collected and can be reused.

  FIG. 2 is a block diagram for explaining a configuration for controlling each part of the substrate processing apparatus. This substrate processing apparatus is provided with a control device 45 for controlling the operations of the above-described units. The control device 45 controls each operation of the chemical liquid valve 6, the pure water valve 9, the three-way valve 14, the gas suction mechanism 17, the opening / closing mechanism 22, the rotation drive mechanism 28, the pure water valve 34, and the chemical liquid pump 41.

  FIG. 3 is a flowchart for explaining the operation of the substrate processing apparatus. The substrate processing flow (FIG. 3A) showing the flow of the substrate processing step and the change in the atmospheric pressure (environmental pressure) of the atmosphere of the substrate W to be processed. The environmental pressure flow (FIG. 3B) showing is shown in contrast. In the substrate loading / unloading process for loading an unprocessed substrate W, the substrate loading / unloading opening of the processing chamber 12 is opened, and the atmospheric pressure in the processing chamber 12 becomes atmospheric pressure (1030 hPa). At this time, the control device 45 stops the rotation drive mechanism 28 and controls the chemical solution valve 6 and the pure water valves 9 and 34 to the closed state, and the three-way valve 14 is connected to the gas introduction path 15 side and is opened and closed. The mechanism 22 is controlled to be opened. The chemical pump 41 may be in a stopped state, but may be held in a driving state when a circulation line for circulating the chemical liquid from the chemical liquid supply path 5 to the chemical liquid tank 40 is provided.

  In this state, an unprocessed substrate W is loaded and delivered to the spin chuck 1 by a substrate transfer robot (not shown). If the processed substrate W that has been processed before is held on the spin chuck 1, the substrate transfer robot first receives the processed substrate W from the spin chuck 1 and discharges it to the outside of the processing chamber 12. Then, the unprocessed substrate W is transferred to the spin chuck 1 in the processing chamber 12.

  Next, a chemical treatment process is performed. At this time, the control device 45 causes the rotation drive mechanism 28 to rotate the rotation shaft 27 at a predetermined chemical solution processing rotation speed. As a result, the substrate W is rotated at the chemical solution processing rotation speed. In this state, the control device 45 opens the chemical liquid valve 6 and discharges the chemical liquid from the chemical liquid supply path 5 from the chemical liquid nozzle 2 toward the center of the upper surface of the substrate W. Thereby, on the upper surface of the substrate W, the supplied chemical solution receives a centrifugal force and spreads outward from the center of rotation to cover the entire upper surface of the substrate W.

  Prior to opening the chemical liquid valve 6 and supplying the chemical liquid, the control device 45 operates the gas suction mechanism 17 and connects the three-way valve 14 to the exhaust passage 16 side. At the same time, the control device 45 closes the opening / closing mechanism 22. After the substrate W is loaded, the processing chamber 12 is closed by closing the substrate loading / unloading port. Thereby, the space in the processing chamber 12 forms a sealed space, and this sealed space is exhausted by the gas suction mechanism 17 through the exhaust / air supply path 13 and the three-way valve 14. Thus, the sealed space in the processing chamber 12 is in a reduced pressure state of 930 hPa or less. More preferably, the space in the processing chamber 12 is held under reduced pressure to 500 hPa or less, more preferably 300 hPa or less (more preferably 30 hPa or less) during the chemical treatment process.

  In the case where the sealed space in the processing chamber 12 is in this reduced pressure atmosphere and the chemical liquid valve 6 is opened and the chemical liquid is supplied from the chemical liquid nozzle 2 to the upper surface of the substrate W, the surface of the substrate W is a hydrophobic surface. Even so, the substrate W exhibits good wettability with respect to the chemical solution, and the entire upper surface of the substrate W is covered with the chemical solution by supplying a small amount of the chemical solution. Thus, the chemical treatment is performed for a predetermined time.

  The rotation speed of the substrate W (rotation speed of the spin chuck 1) in the chemical treatment process is, for example, about 100 to 1000 rpm. When the chemical liquid is continuously discharged from the chemical liquid nozzle 2 while rotating the substrate W at such a chemical liquid processing rotation speed, the supplied chemical liquid spreads quickly on the upper surface of the substrate W, and is excluded from the peripheral portion to the outside. Go. In this way, the upper surface of the substrate W can be efficiently processed while supplying new chemical solutions one after another to each portion of the upper surface of the substrate W. The chemical liquid that has been removed to the outside of the substrate W is received by the inner wall surface of the processing cup 11, and is collected into the chemical liquid tank 40 through the chemical liquid recovery path 10. The collected chemical solution is guided again from the chemical solution tank 40 to the chemical solution supply path 5 and reused.

Since the wettability of the surface of the substrate W to the chemical liquid is good, the chemical liquid may be supplied at a small flow rate. Thereby, since the quantity of the chemical | medical solution which contacts an atmosphere on the board | substrate W can be decreased, the durable life of a chemical | medical solution can be lengthened. As a result, the usage amount of the chemical solution is reduced, so that the substrate processing cost can be reduced.
In addition, since it is sufficient to supply the chemical liquid from the chemical liquid nozzle 2 at a small flow rate, mist generated from the chemical liquid is reduced. Thereby, since contamination due to mist reattachment to the surface of the substrate W can be suppressed, the quality of the substrate processing can be improved.

Furthermore, since the wettability of the surface of the substrate W to the chemical solution is good, even when a fine pattern or hole is formed on the surface of the substrate W, the chemical solution is distributed well in such a pattern or hole. Efficient chemical treatment can be performed.
The chemical treatment process can also be performed by a so-called liquid accumulation process (paddle process). In this case, the control device 45 controls the rotation drive mechanism 28 to control the spin chuck 1 to a rotation stop state or to a low speed rotation state (for example, 10 to 50 rpm or less). In this state, the controller 45 opens the chemical liquid valve 6 for a certain period of time necessary to form a chemical liquid film covering the entire upper surface of the substrate W. As a result, the chemical liquid is deposited on the horizontal substrate W, and a liquid film covering the entire upper surface of the substrate W is formed. During this time, the spin chuck 1 is held in the low-speed rotation state or the rotation stop state so that the liquid film is not broken. In order to hold the liquid film of the chemical solution on the substrate W, the control device 45 may perform control to open the chemical solution valve 6 intermittently as necessary, or to hold the liquid film on the substrate W. The opening degree of the chemical liquid valve 6 may be controlled so that the chemical liquid is supplied at a minute flow rate required for the operation. In this case, for example, a chemical liquid valve 6 having a flow rate adjusting function may be used.

Even in the case where such a liquid deposition process is performed, the surface of the substrate W placed in a reduced-pressure atmosphere can have an apparently good wettability with respect to the chemical solution, and thus covers the entire upper surface of the substrate W. The amount of chemical solution required to form a liquid film is reduced. Thereby, the usage-amount of a chemical | medical solution can be suppressed and the cost of a board | substrate process can be reduced.
When the chemical treatment process is completed in this manner, a rinsing process for washing away the chemical on the substrate W is then performed. In this rinsing process, the control device 45 controls the chemical liquid valve 6 to be closed and opens the pure water valve 9 to discharge pure water from the pure water nozzle 3 onto the substrate W. Further, the control device 45 stops the gas suction mechanism 17 and connects the three-way valve 14 to the gas introduction path 15 side. At the same time, the control device 45 opens the opening / closing mechanism 22. Therefore, in the rinsing step, gas is introduced into the processing chamber 12 via the gas introduction path 15 and the exhaust / air supply path 13, so that the atmospheric pressure inside the processing chamber 12 becomes atmospheric pressure.

Further, the control device 45 controls the rotation drive mechanism 28 to rotate the spin chuck 1 at a rinse processing rotation speed (for example, 300 to 1000 rpm). Accordingly, when pure water is supplied from the pure water nozzle 3 toward the center of the upper surface of the rotating substrate W, the pure water is subjected to centrifugal force and spreads outward in the rotational radius. Replace the chemical with pure water.
On the other hand, the control device 45 opens the pure water valve 34, supplies pure water to the lower surface treatment liquid supply pipe 30, and supplies the pure water from the lower surface treatment liquid nozzle 31 toward the rotation center of the lower surface of the substrate W in a rotating state. Discharge. The pure water spreads outward of the substrate W due to centrifugal force, and covers the entire lower surface of the substrate W. Thus, the rinsing process on the lower surface side of the substrate W is also performed.

In this rinsing process, used pure water is guided to the drainage path 18 by a drainage guide member (not shown) so that the pure water used for the rinsing process does not enter the chemical solution recovery path 10.
Even during the rinsing step, the three-way valve 14 is connected to the exhaust passage 16 side by the control of the control device 45, the gas suction mechanism 17 is operated, and the open / close mechanism 22 is closed, so that the atmosphere in the processing chamber 12 is closed. The atmospheric pressure of (the atmosphere in which the substrate W is placed) may be a reduced pressure atmosphere of 930 hPa or less (more preferably, 500 hPa or less, more preferably 300 hPa or less, most preferably 30 hPa or less). In this way, even if the surface of the substrate W is in a hydrophobic state, the substrate W shows apparently good wettability with respect to the pure water supplied from the pure water nozzle 3. As a result, the surface of the substrate W can be rinsed with a small amount of pure water supplied, so that the cost of substrate processing can be reduced. Furthermore, since the amount of mist generated decreases with a decrease in the amount of pure water supplied, contamination caused by mist reattachment to the substrate W can be reduced. At the same time, even if a fine pattern or hole is formed on the surface of the substrate W, pure water reaches the inside of the substrate W, so that an efficient rinsing process is possible.

  After the rinsing process, a drying process is performed in which moisture on the surface of the substrate W is spun off by centrifugal force and the substrate W is dried. That is, the control device 45 closes the pure water valve 9 to stop the supply of pure water from the pure water nozzle 3 and controls the rotation drive mechanism 28 to rotate the spin chuck 1 at a predetermined drying rotational speed. To speed up. In this drying process, the control device 45 connects the three-way valve 14 to the gas introduction path 15 side, stops the gas suction mechanism 17, and opens the opening / closing mechanism 22. Thereby, the internal space of the processing chamber 12 becomes atmospheric pressure (1030 hPa).

  However, also in this drying step, the inside of the processing chamber 12 may be controlled to a reduced pressure atmosphere. That is, under the control of the control device 45, the three-way valve 14 may be connected to the exhaust passage 16 side, the gas suction mechanism 17 may be operated, and the opening / closing mechanism 22 may be closed. Thereby, the inside of the processing chamber 12 is in a reduced pressure state of 930 hPa or less (more preferably, 500 hPa or less, more preferably 300 hPa or less, and most preferably 30 hPa or less). As a result, the substrate W can be dried in an atmosphere with less oxygen, and so-called watermark generation can be suppressed or prevented.

After the drying step, the substrate loading / unloading opening of the processing chamber 12 is opened, and the processing from the substrate loading / unloading step is repeated. Of course, if there is no substrate to be processed next, only the processed substrate W is carried out.
FIG. 4 is an illustrative view showing a basic configuration of a substrate processing apparatus according to a second embodiment of the present invention. 4, parts corresponding to the respective parts shown in FIG. 1 are denoted by the same reference numerals as those in FIG. In this substrate processing apparatus, unlike the above-described first embodiment, the processing chamber 12A that houses the spin chuck 1 and the processing cup 11 does not need to be sealable. Further, the opening / closing mechanism 22 at the inlet of the exhaust passage 20 is also unnecessary.

  In the substrate processing apparatus of this embodiment, a small sealed space 50 surrounding the substrate W held on the spin chuck 1 is formed. More specifically, a lid member 51 that can be moved up and down so as to approach / separate the spin base 25 is provided above the spin chuck 1, and the lid member 51 is brought into close contact with the upper surface of the spin base 25. Thus, a sealed space 50 surrounding the substrate W held by the spin chuck 1 is formed.

The lid member 51 has a flat hollow cylindrical shape that opens the lower surface facing the spin base 25 and closes the upper surface. A seal member (O-ring) 52 is disposed at the lower end of the side wall. Yes. By pressing the lid member 51 against the upper surface of the spin base 25 through the seal member 52, an airtight sealed space 50 is formed.
The lid member 51 is supported by a lower end of a lid member rotation shaft 53 that is disposed coaxially with the rotation shaft 27 of the spin chuck 1, and the lid member rotation shaft 53 is supported by a lifting drive mechanism 55. It is rotatably attached to the motor via a bearing 56. The elevating drive mechanism 55 is controlled by the control device 45 (see FIG. 2).

  The lid member rotation shaft 53 is a hollow shaft, and an upper surface treatment liquid supply pipe 58 is inserted into the inside thereof. The lower end of the upper surface processing liquid supply pipe 58 forms an upper surface processing liquid nozzle 60 that passes through the top wall 51 a of the lid member 51 and faces the rotation center of the upper surface of the substrate W held by the spin chuck 1. A sealing member (O-ring) 61 is disposed between the upper surface treatment liquid nozzle 60 and the inner wall surface of the through hole of the top wall 51a, thereby ensuring the airtightness of the sealed space 50.

A processing liquid supply path 59 is connected to the upper surface processing liquid supply pipe 58, and a chemical liquid from the chemical liquid valve 6 and pure water from the pure water valve 9 can be supplied to the processing liquid supply path 59. Yes.
On the other hand, the processing liquid supply path is not provided on the lower surface side of the substrate W, and the internal space of the hollow rotating shaft 27 communicates with the sealed space 50 through the central opening of the spin base 25 and is exhausted. / Used as intake passage 63. An exhaust / air supply path 13 communicating with the exhaust / intake path 63 is connected to the lower end of the rotating shaft 27.

The substrate processing flow and the ambient pressure flow are as shown in FIGS. 3A and 3B as in the case of the first embodiment described above.
That is, in the substrate loading / unloading process in which an unprocessed substrate W is loaded or a processed substrate W is unloaded, the control device 45 (see FIG. 2) controls the elevating drive mechanism 55 and the lid member 51. Is disposed at a retracted position spaced above the spin base 25. Therefore, the substrate W is placed in an atmospheric pressure atmosphere.

  In the chemical solution processing step, the control device 45 controls the elevation drive mechanism 55 to bring the lid member 51 into close contact with the upper surface of the spin base 25. As a result, a sealed space 50 is formed between the spin base 25 and the lid member 51. In this state, the control device 45 operates the gas suction mechanism 17 and connects the three-way valve 14 to the exhaust passage 16 side. Thereby, the sealed space 50 is exhausted through the exhaust / air supply paths 63 and 13, and the inside thereof is 930 hPa or less (more preferably, 500 hPa or less, more preferably 300 hPa or less, most preferably 30 hPa or less). The reduced pressure atmosphere.

  In such a state, the control device 45 opens the chemical liquid valve 6. As a result, the chemical liquid is supplied from the upper surface processing liquid nozzle 60 toward the center of the upper surface of the substrate W. In this embodiment, a liquid process (paddle process) is performed in which a chemical film is formed on the upper surface of the substrate W to form a liquid film, and the surface of the substrate W is processed with the chemical liquid constituting the liquid film. Therefore, the control device 45 supplies the chemical liquid for a certain time and closes the chemical liquid valve 6 after the liquid film covering the entire upper surface of the substrate W is formed. Of course, as in the case of the first embodiment described above, the control device 45 intermittently opens the chemical valve 6 as necessary to maintain the liquid film on the substrate W, or at a minute flow rate. You may continue supply of a chemical | medical solution.

The control device 45 also controls the rotation drive mechanism 28 to stop the rotation of the spin chuck 1 or to rotate the spin chuck 1 at a low rotation speed (for example, 10 to 50 rpm) at which the liquid film is not broken. Let it continue. At this time, the lid member 51 and the lid member rotating shaft 53 are rotated together with the spin chuck 1, and the airtight state of the sealed space 50 is maintained.
In the rinsing process, the control device 45 controls the elevating drive mechanism 55 to guide the lid member 51 to a retracted position spaced above the spin base 25. Therefore, the substrate W is placed in an atmospheric pressure atmosphere. In this state, the control device 45 closes the chemical liquid valve 6 and opens the pure water valve 9. Thus, pure water is supplied from the upper surface treatment liquid nozzle 60 toward the center of the upper surface of the substrate W held by the spin chuck 1. On the other hand, the control device 45 rotates the spin chuck 1 at the rinse processing rotation speed. In this way, the chemical solution on the surface of the substrate W is replaced with pure water. Further, the control device stops the gas suction mechanism 17 and connects the three-way valve 14 to the gas introduction path 15 side.

In the drying process, the control device 45 holds the lid member 51 at a retracted position spaced above the spin base 25. Therefore, the substrate W is placed in an atmospheric pressure atmosphere. Then, the control device 45 accelerates the rotation speed of the spin chuck 1 to the drying rotation speed. Thereby, the liquid component on the surface of the substrate W is shaken off by the centrifugal force.
According to this embodiment, in the chemical treatment process, the substrate W is placed in the sealed space 50 whose pressure has been reduced. Therefore, even if the surface of the substrate W is a hydrophobic surface, the surface of the substrate W exhibits good wettability with respect to a chemical solution. As a result, if a small amount of chemical solution is supplied, a liquid film that covers the entire upper surface of the substrate W can be formed. Thereby, since the usage-amount of a chemical | medical solution can be decreased, the cost of a board | substrate process can be reduced. At the same time, the wettability of the surface of the substrate W to the chemical solution is improved. As a result, the chemical solution can be spread to the inside of the fine patterns and holes formed on the surface of the substrate W, so that a good chemical solution treatment is possible. become.

  While the two embodiments of the present invention have been described above, the present invention can also be implemented in other embodiments. For example, in the above-described embodiment, the chemical solution used for substrate processing is recovered and reused. However, the present invention is also applied to a substrate processing apparatus configured to make a used chemical solution disposable. Can do. Also in this case, the chemical solution consumption can be reduced and the cost of substrate processing can be reduced. In addition, various design changes can be made within the scope of the matters described in the claims.

It is an illustration figure which shows the fundamental structure of the substrate processing apparatus which concerns on 1st Embodiment of this invention. It is a block diagram for demonstrating the structure for control of each part of the said substrate processing apparatus. It is a flowchart for demonstrating operation | movement of the said substrate processing apparatus, The substrate processing flow (FIG. 3A) which shows the flow of a substrate processing process, and the environmental pressure which shows the change of the atmospheric pressure (environmental pressure) of the atmosphere of the board | substrate W to be processed. The flow (FIG. 3B) is shown in contrast. It is an illustration figure which shows the fundamental structure of the substrate processing apparatus which concerns on 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Spin chuck 2 Chemical liquid nozzle 3 Pure water nozzle 4 Chemical liquid supply source 5 Chemical liquid supply path 6 Chemical liquid valve 7 Pure water supply source 8 Pure water supply path 9 Pure water valve 10 Chemical liquid recovery path 11 Processing cup 12 Processing chamber 12A Processing chamber 13 Exhaust / Air supply path 14 Three-way valve 15 Gas introduction path 16 Exhaust path 17 Gas suction mechanism 18 Drain path 20 Exhaust path 21 Exhaust equipment 22 Opening / closing mechanism 25 Spin base 26 Chuck pin 27 Rotating shaft 28 Rotation drive mechanism 30 Lower surface processing liquid supply pipe 31 Bottom treatment liquid nozzle 32 Pure water supply source 33 Pure water supply path 34 Pure water valve 40 Chemical liquid tank 41 Chemical liquid pump 45 Controller 50 Sealed space 51 Lid member 51a Top wall 52 Seal member 53 Lid member rotating shaft 54 Support arm 55 Lifting Drive mechanism 56 Bearing 58 Upper surface processing liquid supply pipe 59 Processing liquid supply path 60 Surface treatment liquid nozzle 63 exhaust / supply passageway W substrate

Claims (7)

A substrate holding step of holding the substrate by the substrate holding mechanism;
A treatment liquid supply step for supplying a treatment liquid to the substrate held by the substrate holding mechanism during the substrate holding step;
A substrate processing method characterized in that the processing liquid supply step includes a depressurization step of maintaining a space including the substrate held by the substrate holding mechanism in a depressurized state below a predetermined atmospheric pressure that is lower than the atmospheric pressure.   The substrate processing method according to claim 1, wherein the processing liquid includes a chemical liquid or pure water.   The substrate is held horizontally by the substrate holding mechanism, a processing liquid is deposited on the surface of the horizontally held substrate to hold a liquid film of the processing liquid, and the surface of the substrate is processed by the processing liquid forming the liquid film. The substrate processing method according to claim 1, further comprising a liquid filling step for processing the substrate. The substrate holding mechanism is a substrate holding and rotating mechanism that can hold and rotate a substrate,
2. The method according to claim 1, further comprising a drying step that is performed in parallel with the decompression step after the treatment with the treatment liquid, and that removes the treatment liquid on the substrate surface by rotating the substrate by the substrate holding and rotating mechanism. 4. The substrate processing method according to any one of items 3 to 3. The substrate holding mechanism is housed in a sealable processing chamber,
5. The substrate processing method according to claim 1, wherein the depressurizing step includes a step of bringing the processing chamber into a sealed state and exhausting and depressurizing an internal space of the processing chamber. The substrate holding mechanism includes a base member facing one surface of the substrate,
The depressurizing step includes a step of accommodating the substrate in a sealed space sealed by the base member and the lid member by bringing the lid member into close contact with the base member from the other surface side of the substrate; The substrate processing method according to claim 1, further comprising a step of exhausting and depressurizing. A substrate holding mechanism for holding the substrate;
A processing liquid supply mechanism for supplying a processing liquid to the substrate held by the substrate holding mechanism;
A substrate processing apparatus comprising: a decompression mechanism that decompresses a space including the substrate held by the substrate holding mechanism to a predetermined atmospheric pressure lower than an atmospheric pressure.

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