JP2002367952A - Method and equipment for processing substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of reducing the usage amount of an organic solvent by reducing the unnecessary consumption of the organic solvent used for substituting for a processing liquid attaching to a substrate on the surface of the substrate, when drawing up the substrate out of the processing liquid after dipping it in the processing liquid, and drying it up. SOLUTION: A processing chamber 14 which surrounds a processing bath 10 wherein pure water 12 is stored and a wafer W is dipped in the pure water is depressurized. Thereafter, depressurization is stopped and the processing chamber is airtightly closed. With IPA steam being supplied into the depressurized and closed processing chamber from an upper part of it, the wafer is drawn out of the pure water by means of a lifter 30. After the wafer is completely drawn out of the pure water and the supply of the IPA steam into the processing chamber is stopped, the processing chamber is depressurized again to dry up the wafer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a semiconductor wafer,
Substrate processing method and substrate processing in which a substrate such as a glass substrate for a flat panel display such as a liquid crystal display device, a glass substrate for a photomask, and a substrate for an optical disk are immersed in a processing liquid and then exposed from the processing liquid and dried. Related to the device.

[0002]

2. Description of the Related Art As a method of drying a substrate such as a semiconductor wafer after immersing the substrate in a processing liquid, a method of drying the substrate while exposing the substrate from the processing liquid is generally performed.
In this method, a substrate is immersed in a processing liquid, for example, pure water (rinse liquid) stored in a processing tank disposed inside a processing chamber, and then the substrate is pulled up from the pure water by a lifter mechanism. Alternatively, pure water is discharged from the processing tank while the substrate is held in the processing tank, and the substrate is exposed from the pure water. At this time, a vapor of a water-soluble organic solvent, for example, isopropyl alcohol (IPA) is supplied into the processing chamber using an inert gas, for example, nitrogen gas as a carrier gas. The IPA vapor supplied into the processing chamber condenses on the surface of the substrate kept at a lower temperature, and the pure water attached to the substrate surface is replaced by the IPA. When the substrate is completely exposed from the pure water and the pure water is replaced with IPA on the entire surface of the substrate, the inside of the processing chamber is evacuated by evacuating the processing chamber. Thereby, the IPA condensed on the substrate surface evaporates quickly, and the substrate is dried.

[0003]

In the conventional processing method described above, the IPA vapor supplied into the processing chamber reaches the inner wall surface of the processing chamber, the wall surface of the processing tank, the lifter mechanism, and the like. Both surfaces are cooler than the IPA vapor. For this reason, the surface of unnecessary parts such as the inner wall surface of the processing chamber, the wall surface of the processing tank, and the lifter mechanism can
Condensation of the PA vapor occurs. IPA that did not condense
After the pure water is replaced with IPA on the entire surface of the substrate,
Air is exhausted from the processing chamber. As a result of these,
There is a problem that IPA is wasted and the amount of IPA used cannot be reduced.

The present invention has been made in view of the above circumstances, and when a substrate is immersed in a processing liquid and then exposed from the processing liquid and dried, the processing liquid adhering to the substrate is removed. To provide a substrate processing method capable of reducing the use amount of an organic solvent by reducing wasteful consumption of an organic solvent used for substitution on a substrate surface, and to appropriately carry out the method. It is an object of the present invention to provide a substrate processing apparatus capable of performing the above.

[0005]

The invention according to claim 1 is
After immersing the substrate in the processing solution stored in the processing tank,
In a substrate processing method of exposing and drying a substrate from a processing liquid, a depressurizing step of depressurizing a space above a liquid surface including a liquid surface of the processing liquid in the processing bath, A sealing step of sealing the space, and after this sealing step, a vapor supply step of supplying a vapor of an organic solvent from above to the depressurized and sealed space, and an organic solvent into the depressurized and sealed space. A substrate exposing step of exposing the substrate from the processing liquid in the processing tank while supplying steam.

According to a second aspect of the present invention, there is provided a processing tank in which a processing liquid is stored and a substrate is immersed in the processing liquid; a substrate exposing means for exposing the substrate from the processing liquid in the processing tank; In a substrate processing apparatus comprising: a processing chamber surrounding a periphery of a tank; and vapor supply means for supplying vapor of an organic solvent into the processing chamber from above, a decompression means for decompressing the inside of the processing chamber; A sealing unit that seals the inside of the processing chamber depressurized by the depressurizing unit; and a depressurizing unit that seals the inside of the processing chamber by the sealing unit after depressurizing the inside of the processing chamber. And control means for controlling the supply of the vapor of the organic solvent into the processing chamber.

According to a third aspect of the present invention, in the substrate processing apparatus according to the second aspect, the decompression means has an intake port near a surface of the processing solution in the processing tank and exhausts the inside of the processing chamber. It is characterized by being a vacuum exhaust means.

According to the substrate processing method of the first aspect of the present invention, after the space above the liquid surface of the processing liquid in the processing tank is depressurized, the depressurization is stopped to seal the space. An organic solvent vapor is supplied from above into the closed and decompressed space. Since the vapor of the organic solvent is supplied into the space that is depressurized and sealed as described above, the vapor of the organic solvent immediately becomes saturated or supersaturated in the space. When the vapor of the organic solvent is continuously supplied into the space in such a state from above, the vapor is liquefied in the upper portion of the space to form mist (fine droplets), and this mist formation continues. The mist formed in the upper part of the space falls on the surface of the processing liquid in the processing tank or onto the surface of the substrate exposed from the processing liquid due to its own weight. Then, the mist of the organic solvent that has reached the surface of the substrate is replaced with the processing liquid attached to the surface of the substrate.
When the substrate is completely exposed from the processing liquid and the processing liquid is replaced with an organic solvent over the entire surface of the substrate, the sealed state of the space is released and vacuum evacuation is performed, whereby the organic solvent on the substrate surface is quickly evaporated. Then, the substrate is dried. As described above, since the vapor of the organic solvent supplied into the space becomes a mist at the upper part of the space and diffuses toward the substrate, the condensation of the vapor of the organic solvent on the surface of the unnecessary part is reduced, and the organic solvent is reduced. Waste of solvent is reduced.

In the substrate processing apparatus according to the second aspect of the present invention, the inside of the processing chamber is depressurized by the decompression means, and thereafter, the inside of the processing chamber is sealed by the sealing means. The vapor of the organic solvent is supplied from above into the sealed and decompressed processing chamber by the vapor supply means. Since the vapor of the organic solvent is supplied into the processing chamber which is depressurized and sealed as described above, the vapor of the organic solvent is immediately saturated or supersaturated in the processing chamber. When the vapor of the organic solvent is continuously supplied into the processing chamber in such a state from the upper portion, the vapor is liquefied at the upper portion of the processing chamber to form a mist, and the formation of the mist continues. The mist formed in the upper part of the processing chamber falls on the surface of the processing liquid in the processing tank or onto the surface of the substrate exposed from the processing liquid by the substrate exposing means due to its own weight. Then, the mist of the organic solvent that has reached the surface of the substrate is replaced with the processing liquid attached to the surface of the substrate. When the substrate is completely exposed from the processing liquid and the processing liquid is replaced with an organic solvent over the entire surface of the substrate, the sealed state of the processing chamber is released, and the organic solvent on the substrate surface is quickly removed by performing vacuum evacuation. After evaporation, the substrate is dried. As described above, since the vapor of the organic solvent supplied into the processing chamber becomes a mist at the upper part of the processing chamber and diffuses toward the substrate, the condensation of the vapor of the organic solvent on the surface of the unnecessary portion is reduced. In addition, wasteful consumption of the organic solvent is reduced.

In the substrate processing apparatus according to the third aspect of the present invention,
Since the vapor of the processing liquid, e.g., water vapor, evaporating from the processing liquid in the processing tank is sucked through the intake port arranged near the liquid surface of the processing liquid and efficiently discharged from the processing chamber,
Water vapor is prevented from diffusing into the processing chamber.
For this reason, it is possible to prevent the organic solvent supplied into the processing chamber from absorbing water vapor, being diluted, and being wasted.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below with reference to FIG.

FIG. 1 is a schematic diagram showing an example of a schematic configuration of a substrate processing apparatus used to carry out a substrate processing method according to the present invention. In this substrate processing apparatus, a processing solution, for example, pure water 12 is stored, and a substrate, for example, a semiconductor wafer W is immersed in the pure water 12, and a rinsing process is performed. A processing chamber 14 is provided.

Although a detailed illustration and description of the treatment tank 10 are omitted, a supply port 16 and a drain port 1 of pure water are provided at a lower portion thereof.
8 and an overflow section 20 from which pure water overflows. A pure water supply pipe 22 in which an open / close control valve 24 is interposed is connected to the supply port 16 of the processing tank 10, and the pure water supply pipe 22 is connected to a pure water supply source. In addition, a drain pipe 26 having an opening / closing control valve 28
Are connected and connected.

The processing chamber 14 can be loaded and unloaded by opening and closing a lid (not shown), and can be sealed. A lifter 30 driven up and down is provided inside the processing chamber 14. The lifter 30 receives the wafer W carried into the processing chamber 14, inserts the wafer W into the processing tank 10, supports the wafer W in the processing tank 10, and removes the processed wafer W from the processing tank 10. Take out. A drain port 32 is provided at the bottom of the processing chamber 14.
The drain port 3 has a drain pipe 3 in which an open / close control valve 36 is inserted.
4 are in communication.

A steam supply nozzle 38 is provided at an upper portion in the processing chamber 14. Steam supply nozzle 3
A steam supply pipe 40 is connected to 8 and is connected thereto. The steam supply pipe 40 is connected to a gas supply pipe 42 connected to a supply source of an inert gas, for example, nitrogen gas. A line heater 44 is provided in the steam supply pipe 40. An opening / closing control valve 46 is interposed in the gas supply pipe 42, and a bypass pipe 48 that branches at a position upstream of the opening / closing control valve 46 and joins at a position downstream of the opening / closing control valve 46 is provided. Have been. In the middle of the bypass pipe 48,
An organic solvent, for example, IPA 50 is stored and hermetically sealed, and an IPA vapor generation tank 52 is provided in a closed space above the liquid surface, in which a nitrogen gas inlet of the bypass pipe 48 and an IPA vapor outlet are respectively connected. The bypass pipe 48 has an I
Opening / closing control valves 54 and 56 are interposed on the upstream and downstream sides of the PA steam generation tank 52, respectively. The IPA vapor generation tank 52 is provided with a heater 58 for heating the IPA 50 stored inside. Then, in the IPA vapor generation tank 52, the IPA 50 is heated by the heater 58 to generate IPA vapor. The IPA vapor generated in the IPA vapor generation tank 52 is sent from the bypass pipe 48 to the vapor supply pipe 40 using the nitrogen gas of 1 atm or more as a carrier gas, passes through the vapor supply pipe 40, and passes through the vapor supply nozzle in the processing chamber 14. 38.

An intake port 60 is disposed in the processing chamber 14 near the level of the pure water 12 in the processing tank 10, and a vacuum exhaust pipe 62 communicates with the intake port 60. The vacuum exhaust pipe 62 is provided with an opening / closing control valve 64 and a vacuum pump 66, respectively. Although not shown, the operation of the vacuum pump 66, the lifting / lowering operation of the lifter 30, and the opening / closing control valves 24, 28, 36, 46, 54, 5
A controller is provided for controlling the opening and closing operations of 6, 64 according to a predetermined sequence.

Next, an example of a wafer drying operation performed after rinsing with pure water using the above-configured substrate processing apparatus will be described.

The wafer W is immersed in the pure water 12 stored in the processing tank 10 to perform a rinsing process on the wafer W. When the rinsing process is completed, the vacuum pump 66 is operated and the open / close control valve 64 is operated. With the open / close control valves 54 and 56 closed, the processing chamber 14 is evacuated. When the pressure inside the processing chamber 14 is reduced to, for example, about 100 Torr, the open / close control valve 64 is closed, the vacuum pump 66 is stopped, and the open / close control valve 46 is also closed to maintain the reduced pressure inside the processing chamber 14. To seal the inside of the processing chamber 14.

Next, the opening / closing control valves 54 and 56 are opened, and the nitrogen gas is used as a carrier gas and the IPA vapor generation tank 52
The PA vapor is sent into the steam supply pipe 40, and the IPA vapor is sent to the steam supply nozzle 38 through the steam supply pipe 40 while being kept warm by the line heater 44, so that the pressure inside the processing chamber 14 is reduced and sealed. The IPA vapor is supplied from the vapor supply nozzle 38 to the nozzle. Then, the lifter 30 is driven while the supply of the IPA vapor into the processing chamber 14 is continued, and the wafer W is slowly pulled up from the pure water 12 in the processing tank 10 by the lifter 30.

At this time, the IPA vapor is supplied into the processing chamber 14 which has been depressurized and sealed, so that the IPA vapor is immediately saturated or supersaturated in the processing chamber 14. Then, the IPA vapor is continuously supplied from the upper portion into the processing chamber 14 in which the IPA vapor is saturated or supersaturated, whereby the IPA vapor is liquefied in the upper portion of the processing chamber 14 to form an IPA mist. The formation of this mist continues. The mist formed in the upper part of the processing chamber 14 falls on the liquid surface of the pure water 12 in the processing tank 10 or onto the surface of the wafer W exposed from the pure water 12. Then, the IPA mist reaching the surface of the wafer W is replaced with pure water adhering to the surface of the wafer W.

When the wafer W is completely lifted from the pure water 12 in the processing tank 10 and the pure water is replaced with IPA on the entire surface of the wafer W, the open / close control valves 54 and 56 inserted in the bypass pipe 48 are provided. Is closed, and the supply of the IPA vapor into the processing chamber 12 is stopped. Then, the open / close control valve 28 inserted in the drain pipe 26 is opened to drain the water from the processing tank 10,
After opening / closing the control valve 46 inserted in the gas supply pipe 42 and purging the processing chamber 12 with nitrogen gas, the vacuum pump 66 is operated again while the wafer W is held inside the processing chamber 12. Then, the open / close control valve 64 is opened, and the processing chamber 14 is evacuated through the evacuation pipe 62. Thus, IPA is quickly evaporated and removed from the surface of the wafer W held in the processing chamber 12, and the drying of the wafer W is completed. When the drying process of the wafer W is completed, the evacuation is stopped, and then the lid of the processing chamber 12 is opened, and the wafer W is carried out of the processing chamber 12.

In the above-described embodiment, the wafer W that has been rinsed with pure water is lifted by the lifter 30 to expose the wafer W from the pure water 12 in the processing bath 10. By keeping the wafer W after the rinsing process stationary in the processing tank 10 and slowly draining the water from the processing tank 10 through the drain pipe 26 to lower the liquid level of the pure water 12 in the processing tank 10, The wafer W may be exposed from the pure water 12. Further, when the intake port 60 is disposed near the liquid level of the pure water 12 in the processing tank 10 as in the above embodiment, the pure water 12 in the processing tank 10
The water vapor evaporating from the water is efficiently exhausted from the processing chamber 10, and the diffusion of the water vapor into the processing chamber 10 is suppressed. Therefore, the IPA supplied into the processing chamber 10 is diluted by absorbing the water vapor. Although it is preferable to prevent wasteful consumption, it is not always necessary to arrange the intake port 60 near the liquid level of the pure water 12 in the processing tank 10.

[0023]

According to the substrate processing method of the present invention, when the substrate is immersed in the processing liquid and then exposed from the processing liquid and dried, the processing liquid adhering to the substrate and the substrate surface are removed. Since wasteful consumption of the organic solvent used for substitution can be reduced, the amount of the organic solvent used can be reduced.

When the substrate processing apparatus according to the second aspect of the present invention is used, the method according to the first aspect of the present invention can be suitably performed, so that the amount of the organic solvent used can be reduced.

In the substrate processing apparatus according to the third aspect of the present invention,
It is possible to prevent the organic solvent supplied into the processing chamber from being wasted.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an example of a schematic configuration of a substrate processing apparatus used to carry out a substrate processing method according to the present invention.

[Explanation of symbols]

W Semiconductor wafer 10 Processing tank 12 Pure water 14 Processing chamber 22 Pure water supply pipe 24, 28, 36, 46, 54, 56, 64 Open / close control valve 26, 34 Drain pipe 30 Lifter 38 Steam supply nozzle 40 Steam supply pipe 42 Gas Supply pipe 44 Line heater 48 Bypass pipe 50 IPA 52 IPA vapor generation tank 60 Intake port 62 Vacuum exhaust pipe 66 Vacuum pump

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Masahiro Satake 4-chome Tenjin Kitamachi 1-chome, Horikawa-dori-Terauchi, Kamigyo-ku, Kyoto Dainippon Screen Mfg. Co., Ltd. (72) Inventor Yoshitaka Abiko Kamigyo, Kyoto-shi Horikawa-dori Terunouchi-ku 4-chome Tenjin 1 Kitamachi 1 Dainippon Screen Mfg. Co., Ltd. F-term (reference) 3B201 AA03 BB04 BB13 BB72 BB82 BB93 BB95 CC01 CC15 5F046 LA09 LA18

Claims (3)

[Claims] 1. A substrate processing method for immersing a substrate in a processing liquid stored in a processing tank, exposing the substrate from the processing liquid, and drying the substrate, wherein a liquid level of the processing liquid in the processing tank is adjusted. A depressurizing step of depressurizing the space above the liquid surface containing the liquid, a sealing step of stopping the depressurization to seal the space after the depressurizing step, and after the sealing step, an organic material is introduced into the depressurized and sealed space from above the space. A vapor supply step of supplying a vapor of the solvent, and a substrate exposure step of exposing the substrate from the processing liquid in the processing tank while supplying the vapor of the organic solvent into the space that is reduced in pressure and sealed. A substrate processing method characterized by the above-mentioned. 2. A processing tank in which a processing liquid is stored and a substrate is immersed in the processing liquid, substrate exposure means for exposing the substrate from the processing liquid in the processing tank, and processing surrounding the processing tank. In a substrate processing apparatus, comprising: a chamber; and a vapor supply unit for supplying vapor of an organic solvent into the processing chamber from above. A pressure reducing unit configured to reduce the pressure in the processing chamber. A sealing means for sealing the inside of the processing chamber; and a pressure reducing means for reducing the inside of the processing chamber by the pressure reducing means, and then sealing the inside of the processing chamber with the sealing means. And a control means for controlling the supply of the steam. 3. The substrate processing apparatus according to claim 2, wherein said decompression means is a vacuum evacuation means having an air inlet near the surface of the processing liquid in said processing tank and evacuating said processing chamber.