JP3999946B2 - Substrate processing method and substrate processing apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
In this invention, a substrate such as a semiconductor wafer, a glass substrate for a flat panel display such as a liquid crystal display device, a glass substrate for a photomask, a substrate for an optical disk, etc. is immersed in the processing liquid and then exposed from the processing liquid and dried. The present invention relates to a substrate processing method and a substrate processing apparatus.
[0002]
[Prior art]
As a method of drying after immersing a substrate such as a semiconductor wafer in a processing solution, a method of drying while exposing the substrate from the processing solution is generally performed. In this method, after the substrate is immersed in a processing liquid stored in a processing tank disposed inside the processing chamber, for example, pure water (rinsing liquid), the substrate is lifted 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 such as isopropyl alcohol (IPA) is supplied into the processing chamber using an inert gas such as nitrogen gas as a carrier gas. The IPA vapor supplied into the processing chamber condenses on the surface of the substrate held at a lower temperature, and the pure water adhering to the substrate surface is replaced by IPA. When the substrate is completely exposed from the pure water and the pure water is replaced with IPA over the entire surface of the substrate, the inside of the processing chamber is evacuated to a reduced pressure. As a result, the IPA condensed on the substrate surface quickly evaporates and the substrate is dried.
[0003]
[Problems to be solved by the invention]
In the above-described conventional processing method, 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. It is low temperature. For this reason, condensation of IPA vapor also occurs on the surfaces of unnecessary portions such as the inner wall surface of the processing chamber, the wall surface of the processing tank, and the lifter mechanism. Further, the IPA vapor that has not been condensed is exhausted from the processing chamber after pure water is replaced with IPA over the entire surface of the substrate. As a result, there is a problem that IPA is wasted and the amount of IPA used cannot be reduced.
[0004]
The present invention has been made in view of the above circumstances. When the substrate is immersed in the processing liquid and then exposed and dried, the processing liquid attached to the substrate and the substrate surface are used. To provide a substrate processing method capable of reducing wasteful consumption of an organic solvent used for replacement and reducing the amount of the organic solvent used, and a substrate capable of suitably implementing the method. An object is to provide a processing apparatus.
[0005]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a substrate processing method in which the substrate is immersed in the processing liquid stored in the processing tank, and then the substrate is exposed and dried from the processing liquid. a depressurizing step of depressurizing the liquid surface of the space containing the liquid surface, after the pressure reduction step, a sealing step of sealing the space to stop the vacuum, after the sealing step, the to decompressed sealed the space A vapor supply step of supplying an organic solvent vapor from the upper portion to make the space saturated or supersaturated with the organic solvent vapor, and continuously supplying the organic solvent vapor from the upper portion into the space in this state; And a substrate exposure step of exposing the substrate from the processing liquid in the processing tank while supplying vapor of the organic solvent into the space that has been decompressed and sealed.
[0006]
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, and the periphery of the processing tank In the substrate processing apparatus comprising: a processing chamber that surrounds the processing chamber; and a vapor supply means for supplying an organic solvent vapor into the processing chamber from above, a decompression means for decompressing the interior of the processing chamber, and the decompression means A sealing means for sealing the inside of the processing chamber that has been depressurized; and after the pressure in the processing chamber is reduced by the pressure reducing means, the pressure reduction by the pressure reducing means is stopped and the inside of the processing chamber is sealed by the sealing means; wherein the steam supply means into the processing chamber of the organic solvent in the organic solvent the processing chamber by supplying steam of the steam in the saturated or supersaturated Deliberately, characterized in that it further comprises control means for controlling to supply subsequently a vapor of an organic solvent, the by the steam supply means into the processing chamber in this state.
[0007]
According to a third aspect of the present invention, there is provided the substrate processing apparatus according to the second aspect, wherein the decompression unit has an intake port near a liquid level of the processing liquid in the processing tank and exhausts the processing chamber. It is characterized by being.
[0008]
According to the substrate processing method of the first aspect of the invention, after the space above the liquid surface of the processing liquid in the processing tank is decompressed, the decompression is stopped and the space is sealed. The organic solvent vapor is supplied into the sealed and decompressed space from above. Since the vapor of the organic solvent is supplied into the pressure-reduced and sealed space, the vapor of the organic solvent is immediately saturated or supersaturated in the space. When the vapor of the organic solvent is continuously supplied from above into the space in such a state, the vapor is liquefied at the upper part of the space to form mist (microdroplets), and this mist formation continues. The mist formed in the upper part of the space pours onto the surface of the processing liquid in the processing tank and 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 treatment liquid adhering to the surface of the substrate. When the substrate is completely exposed from the processing solution, and the processing solution is replaced with an organic solvent over the entire surface of the substrate, the organic solvent on the substrate surface evaporates quickly by releasing the vacuum from the sealed state of the space. Then, the substrate is dried. As described above, the vapor of the organic solvent supplied into the space becomes a mist in the upper part of the space and diffuses toward the substrate, so that the condensation of the vapor of the organic solvent on the surface of the unnecessary portion is reduced and the organic solvent is reduced. Wasteful consumption of solvent is reduced.
[0009]
In the substrate processing apparatus according to the second aspect of the invention, the inside of the processing chamber is decompressed by the decompression means, and then the inside of the processing chamber is sealed by the sealing means. Vapor of the organic solvent is supplied into the sealed and depressurized processing chamber from above by the vapor supply means. Since the vapor of the organic solvent is supplied into the process chamber which has been decompressed and sealed in this way, the vapor of the organic solvent is immediately saturated or supersaturated in the process chamber. When the vapor of the organic solvent is continuously supplied from the upper part into the processing chamber in such a state, the vapor is liquefied to form mist at the upper part of the processing chamber, and the formation of this mist continues. The mist formed in the upper part of the processing chamber pours onto the surface of the processing liquid in the processing tank or 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 treatment liquid adhering to the surface of the substrate. When the substrate is completely exposed from the processing liquid and the processing liquid is replaced with the organic solvent on the entire surface of the substrate, the organic solvent on the substrate surface is quickly removed by releasing the vacuum from the processing chamber in a sealed state. The substrate is evaporated by evaporation. As described above, since the organic solvent vapor supplied into the processing chamber becomes a mist in the upper part of the processing chamber and diffuses toward the substrate, the condensation of the organic solvent vapor on the surface of unnecessary portions is reduced. , Wasteful consumption of organic solvents is reduced.
[0010]
In the substrate processing apparatus according to the third aspect of the present invention, the vapor of the processing liquid evaporating from the processing liquid in the processing tank, for example, water vapor is sucked through the intake port disposed near the liquid level of the processing liquid and is efficiently supplied from the processing chamber. Since it is discharged well, it is possible to suppress the diffusion of water vapor into the processing chamber. For this reason, it is prevented that the organic solvent supplied into the processing chamber absorbs water vapor and is diluted and consumed wastefully.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
A preferred embodiment of the present invention will be described below with reference to FIG.
[0012]
FIG. 1 is a schematic diagram showing an example of a schematic configuration of a substrate processing apparatus used for carrying out a substrate processing method according to the present invention. The substrate processing apparatus surrounds a processing bath 10 in which a processing liquid, for example, pure water 12 is stored and a substrate, for example, a semiconductor wafer W is immersed in the pure water 12 and rinsed, and the periphery of the processing bath 10. A processing chamber 14 is provided.
[0013]
Although the detailed illustration and description of the treatment tank 10 are omitted, the treatment tank 10 has a supply port 16 and a drain port 18 for pure water in the lower part and an overflow part 20 from which pure water overflows in the upper part. A pure water supply pipe 22 having an open / close control valve 24 inserted therein is connected to the supply port 16 of the treatment tank 10, and the pure water supply pipe 22 is connected to a pure water supply source. Further, a drain pipe 26 having an open / close control valve 28 inserted therein is connected to the drain port 18 in communication therewith.
[0014]
The processing chamber 14 can carry in and out the wafer W by opening and closing a lid (not shown), and can be sealed. A lifter 30 that is driven up and down is disposed inside the processing chamber 14. The lifter 30 receives the wafer W carried into the processing chamber 14, inserts it into the processing tank 10, supports the wafer W in the processing tank 10, and transfers the processed wafer W from the processing tank 10. Take out. In addition, a drain port 32 is provided at the bottom of the processing chamber 14, and a drain pipe 34 having an open / close control valve 36 communicated with the drain port 32.
[0015]
In addition, a vapor supply nozzle 38 is provided in the upper portion of the processing chamber 14. A steam supply pipe 40 is connected to the steam supply nozzle 38, and 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. The steam supply pipe 40 is provided with a line heater 44 interposed therebetween. An opening / closing control valve 46 is inserted 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. It has been. In the middle of the bypass pipe 48, there is provided an IPA vapor generation tank 52 in which an organic solvent, for example, IPA 50 is stored and sealed, and the nitrogen gas inlet and the IPA vapor outlet of the bypass pipe 48 communicate with the sealed space on the liquid surface. It has been. In addition, on the bypass pipe 48, open / close control valves 54 and 56 are inserted on the upstream side and the downstream side of the IPA steam generation tank 52, respectively. The IPA vapor generation tank 52 is provided with a heater 58 for heating the IPA 50 stored therein. In the IPA vapor generating 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 fed into the vapor supply pipe 40 from the bypass pipe 48 using nitrogen gas of 1 atm or more as a carrier gas, and passes through the vapor supply pipe 40 to supply the vapor supply nozzle in the processing chamber 14. 38.
[0016]
In addition, an intake port 60 is disposed in the processing chamber 14 near the liquid surface 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 open / close control valve 64 and a vacuum pump 66. Although not shown in the drawing, controllers that control the operation of the vacuum pump 66, the lifting / lowering operation of the lifter 30 and the opening / closing operations of the opening / closing control valves 24, 28, 36, 46, 54, 56, 64 according to a predetermined sequence are provided. Is provided.
[0017]
Next, an example of a wafer drying process performed after the rinse process with pure water using the substrate processing apparatus having the above-described configuration will be described.
[0018]
The wafer W is immersed in the pure water 12 stored in the processing tank 10 to rinse the wafer W. When the processing is completed, the vacuum pump 66 is operated to open and close the open / close control valve 64. With the control valves 54 and 56 closed, the inside of the processing chamber 14 is evacuated. When the inside of the processing chamber 14 is depressurized to about 100 Torr, for example, the open / close control valve 64 is closed, the vacuum pump 66 is stopped, the open / close control valve 46 is also closed, and the decompressed state inside the processing chamber 14 is maintained. Thus, the inside of the processing chamber 14 is sealed.
[0019]
Next, the open / close control valves 54 and 56 are opened, the vapor of IPA is sent into the vapor supply pipe 40 from the IPA vapor generation tank 52 using nitrogen gas as a carrier gas, and the vapor supply pipe is kept warm by the line heater 44. The vapor is supplied to the vapor supply nozzle 38 through 40, and the IPA vapor is supplied from the vapor supply nozzle 38 into the processing chamber 14 that has been decompressed and sealed. 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 lifted from the pure water 12 in the processing bath 10 by the lifter 30.
[0020]
At this time, since the IPA vapor is supplied into the process chamber 14 which is decompressed and sealed, the IPA vapor is immediately saturated or supersaturated in the process chamber 14. Then, the IPA vapor is continuously supplied into the processing chamber 14 in which the IPA vapor is saturated or supersaturated from the upper portion thereof, whereby the IPA vapor is liquefied at the upper portion of the processing chamber 14 to form IPA mist. This mist formation continues. The mist formed in the upper part of the processing chamber 14 pours onto the surface of the pure water 12 in the processing tank 10 and the surface of the wafer W exposed from the pure water 12. Then, the IPA mist that has reached the surface of the wafer W is replaced with pure water adhering to the surface of the wafer W.
[0021]
When the wafer W is completely pulled up from the pure water 12 in the processing tank 10 and the pure water is replaced with IPA over the entire surface of the wafer W, the open / close control valves 54 and 56 inserted in the bypass pipe 48 are closed, The supply of 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 water from the inside of the processing tank 10, and the open / close control valve 46 inserted in the gas supply pipe 42 is opened to open the inside of the processing chamber 12 with nitrogen gas. After purging, the vacuum pump 66 is operated again with the wafer W held in the processing chamber 12, the open / close control valve 64 is opened, and the processing chamber 14 is evacuated through the vacuum exhaust pipe 62. . As a result, 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, the lid of the processing chamber 12 is opened, and the wafer W is unloaded from the processing chamber 12.
[0022]
In the above-described embodiment, the wafer W that has been rinsed with pure water is pulled up by the lifter 30 so that the wafer W is exposed from the pure water 12 in the processing bath 10. The wafer W is kept stationary in the processing tank 10 and slowly drained from the processing tank 10 through the drain pipe 26 to lower the level of the pure water 12 in the processing tank 10, thereby reducing the pure water 12. The wafer W may be exposed from the inside. Moreover, when the intake port 60 is disposed near the liquid surface of the pure water 12 in the processing tank 10 as in the above embodiment, water vapor evaporated from the pure water 12 in the processing tank 10 is efficiently discharged from the processing chamber 10. As a result, it is possible to prevent the water vapor from diffusing into the processing chamber 10, thereby preventing the IPA supplied into the processing chamber 10 from absorbing and diluting the water vapor and wasting it wastefully. Although it is preferable, the intake port 60 is not necessarily arranged near the liquid surface of the pure water 12 in the treatment tank 10.
[0023]
【The invention's effect】
According to the substrate processing method of the first aspect of the present invention, when the substrate is immersed in the processing liquid and then exposed from the processing liquid and dried, it is used to replace the processing liquid attached to the substrate with the substrate surface. Since wasteful consumption of the organic solvent can be reduced, the amount of the organic solvent used can be reduced.
[0024]
When the substrate processing apparatus of the invention according to claim 2 is used, the method of the invention according to claim 1 can be suitably carried out, so that the amount of organic solvent used can be reduced.
[0025]
In the substrate processing apparatus according to the third aspect of the present invention, it is possible to prevent wasteful consumption of the organic solvent supplied into the processing chamber.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing an example of a schematic configuration of a substrate processing apparatus used for carrying 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 Steam Generation Tank 60 Inlet 62 Vacuum Exhaust Pipe 66 Vacuum Pump

Claims (3)

In the substrate processing method of immersing the substrate in the processing liquid stored in the processing tank and then exposing the substrate from the processing liquid and drying it,
A depressurization step of depressurizing the space above the liquid surface including the liquid surface of the treatment liquid in the treatment tank;
After this pressure reduction step, a sealing step of sealing the space to stop the vacuum,
After this sealing step, the vapor of the organic solvent is supplied from above into the space that has been depressurized and sealed so that the space is saturated or supersaturated with the vapor of the organic solvent, and the upper portion of the space is filled into the space. A steam supply process for continuously supplying the vapor of the organic solvent from,
A substrate exposing step of exposing the substrate from the processing liquid in the processing tank while supplying vapor of the organic solvent into the space that has been decompressed and sealed;
A substrate processing method comprising: A treatment tank in which the treatment liquid is stored and the substrate is immersed in the treatment liquid;
Substrate exposing means for exposing the substrate from the processing liquid in the processing tank;
A processing chamber surrounding the processing tank;
Vapor supply means for supplying organic solvent vapor into the processing chamber from above;
In a substrate processing apparatus comprising:
Decompression means for decompressing the inside of the processing chamber;
Sealing means for sealing the inside of the processing chamber decompressed by the decompression means;
After the pressure inside the processing chamber is reduced by the pressure reduction means, the pressure reduction by the pressure reduction means is stopped , the inside of the processing chamber is sealed by the sealing means, and then the vapor of the organic solvent is introduced into the processing chamber by the vapor supply means. Control means for supplying and controlling the inside of the processing chamber to be saturated or supersaturated with organic solvent vapor, and continuously supplying the organic solvent vapor to the processing chamber in this state by the vapor supply means ;
A substrate processing apparatus further comprising:   The substrate processing apparatus according to claim 2, wherein the decompression unit is a vacuum exhaust unit having an intake port near a liquid level of the processing liquid in the processing tank and exhausting the processing chamber.

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