JP2003075067A - Cleaning/drying apparatus for substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cleaning/drying apparatus for a substrate wherein in the case where after a substrate is washed with pure water, the surface of the substrate is dried, any particle is suppressed from adhering to the surface of the substrate, whereby the surface of the substrate can be rapidly dried without particular heating for the substrate but with less amount of an organic solvent for the drying process. SOLUTION: There are provided a cleaning/drying processing section 10 in which a substrate is immersed in pure water contained in a cleaning tank 12 for cleaning thereof, and is contained in a closed chamber 16 for drying thereof with the vapor of an organic solvent, a vapor production unit 92 for heating the organic solvent to produce the vapor of the organic solvent, and a filter 94 for cleaning the vapor of the organic solvent produced in the vapor production unit 92. The vapor of the organic solvent produced through the vapor production unit 92 and cleaned through the filter 94 is fed into the closed chamber 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device manufacturing process, a liquid crystal display manufacturing process, an electronic part-related manufacturing process, etc., after cleaning various substrates such as silicon wafers, glass substrates, electronic parts, etc. with pure water. The present invention relates to a substrate cleaning / drying processing device for drying a surface.

[0002]

2. Description of the Related Art As a method of cleaning various substrates such as silicon wafers using warm water and drying the surface of the substrate after the cleaning, for example, as disclosed in Japanese Patent Laid-Open No. 30330/1991. The method is known. In the publication, a substrate is housed in a chamber, hot water is injected into the chamber to immerse the substrate in the hot water, and then the chamber is depressurized to a vapor pressure of the hot water or less to boil the hot water. After cleaning the substrate by reduced pressure boiling of water, injecting pure water into the chamber after the cleaning, rinsing the substrate with pure water to clean it, draining the water in the chamber, and evacuating the chamber, A substrate cleaning / drying treatment method for drying a cleaned substrate is disclosed. Also,
In the same publication, when the water in the chamber is discharged, nitrogen gas is supplied into the chamber at the same time as the drainage of the water, thereby effectively preventing dust from adhering to the substrate by the nitrogen gas. Is disclosed.

Further, in Japanese Laid-Open Patent Publication No. 3-169013, hot water is put in a sealed container, a semiconductor wafer is suspended and supported in the container, immersed in warm water for cleaning, and then the wafer is placed in the container. While holding it so that it does not move, isopropyl alcohol (IP
While supplying dry steam such as A), water is discharged from the bottom of the container, and water is dried from the wafer surface while controlling the outflow rate of water and the inflow rate of dry steam so that no water droplets remain on the wafer surface. A method is disclosed in which the wafer is dried by replacing it with steam and then introducing an inert, non-condensable gas such as dry nitrogen into the container to purge the dry steam from the wafer surface. .

[0004]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the method disclosed in Japanese Patent No. 0330, the substrate is washed with warm water, rinsed with pure water, and then drained from the chamber while the substrate is stationary. In this way, the substrate is drained while it is stationary, and the liquid level in the chamber is lowered to remove water from the surroundings of the substrate. Particles that have been removed and diffused in the liquid concentrate in the vicinity of the liquid surface. Therefore, when the liquid level descends on the stationary surface of the substrate, particles are likely to be reattached to the surface of the substrate.

Further, in the method disclosed in Japanese Patent Application Laid-Open No. 3-169013, after washing a substrate with hot water in a closed container, the substrate is drained from the container while the substrate is stationary and IPA vapor or the like is discharged into the container. Supply dry steam,
The substrate is dried by replacing water with IPA vapor or the like. As described above, since the substrate is dried only by substituting the water with IPA vapor while keeping the substrate stationary in the closed container, a large amount of organic solvent such as IPA is required. However, if the temperature of the substrate is not raised to around the boiling point of the organic solvent used, eg, 80 ° C. for IPA, the IPA vapor-condensed on the substrate surface will not evaporate rapidly, and the drying time There is a problem that it becomes long.

The present invention has been made in view of the above circumstances, and when a substrate such as a silicon wafer is washed with pure water and then the substrate surface is dried, the adhesion of particles to the substrate surface is prevented. The amount of organic solvent used for the drying process can be kept low, and the amount of organic solvent used for the drying process is small, and the substrate is washed and dried so that it can be dried quickly even without heating the substrate. The purpose is to provide a device.

[0007]

The invention according to claim 1 is
After cleaning the substrate by immersing the substrate in pure water stored in the cleaning tank in the substrate cleaning / drying processing apparatus, and then cleaning it in a closed chamber having a substrate storage space above the cleaning tank. A cleaning / drying processing unit for accommodating the substrate and drying the substrate with the vapor of the organic solvent; vapor generating means for heating the organic solvent to generate vapor of the organic solvent; and organic vapor generated by the vapor generating means. It is characterized by comprising a filter for cleaning the solvent vapor, and a vapor feeding means for feeding the vapor of the organic solvent generated by the vapor generating means and purified by the filter into the closed chamber.

According to a second aspect of the present invention, in the substrate cleaning / drying apparatus according to the first aspect, there is provided heating means for heating the closed chamber, and the organic solvent is placed in the closed chamber heated by the heating means. The steam of the organic solvent cleaned by the filter is heated by sending the steam of.

According to a third aspect of the present invention, in the substrate cleaning / drying apparatus according to the first or second aspect, the vapor supply means is configured to supply the vapor generating means and the vapor from an inert gas supply source. It is characterized in that the filters are gas supply means for supplying an inert gas together with the vapor of the organic solvent into the closed chamber through the respective pipelines provided therein.

According to a fourth aspect of the present invention, in the substrate cleaning / drying apparatus according to the third aspect, the inert gas sent from the inert gas supply source to the vapor generating means is heated by the gas supply means. It further comprises a gas heating means for controlling.

According to a fifth aspect of the present invention, in the substrate cleaning / drying apparatus according to the third or fourth aspect, the vapor generating means blows an inert gas into the organic solvent to vaporize the organic solvent. Is generated.

According to a sixth aspect of the present invention, in the substrate cleaning / drying apparatus according to any one of the first to fifth aspects, the vapor generating means has a temperature adjusting function and adjusts the temperature to a predetermined temperature. It is characterized in that the vapor of the generated organic solvent is generated.

According to a seventh aspect of the present invention, in the substrate cleaning / drying apparatus according to any one of the first to sixth aspects, the filter is provided before the vapor of the organic solvent is supplied into the closed chamber. Is characterized by heating.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to the drawings.

1 and 2 show a first embodiment of the present invention.
As an example, FIG. 1 is a schematic diagram showing the overall configuration of a substrate cleaning / drying processing apparatus, and FIG. 2 is a side sectional view showing the configuration of a cleaning / drying processing unit of the apparatus.

First, the structure of the cleaning / drying processing section 10 will be described. The cleaning / drying processing unit 10 includes a cleaning tank 12, an overflow water receiving unit 14, and a closed chamber 16. The cleaning tank 12 has a pure water supply port 18 formed at the bottom thereof, and an overflow portion 20 formed at the top thereof,
The cleaning tank 12 and the overflow water receiving portion 14 have a double tank structure so that pure water overflowing from the cleaning tank 12 beyond the overflow portion 20 flows into the overflow water receiving portion 14. Further, the cleaning tank 12 has an inner volume such that a substrate, for example, a cassette C containing a plurality of silicon wafers can be completely immersed in pure water contained therein. And cleaning tank 1
2 and the space above the overflow water receiving portion 14 are the closed chamber 1
It is enclosed in a closed manner by 6. Closed chamber 16
An opening 22 for taking in and out the cassette C accommodating a plurality of wafers is formed on the front side of the, and a sealing lid 24 that can openably and closably close the opening 22 is provided. . A vapor supply port 26 is formed on the side wall surface of the closed chamber 16. Further, a rubber heater 25 is provided on the outer wall surface of the closed chamber 16 so as to cover it, and a thermometer for detecting the temperature of the inner wall surface of the closed chamber 16 is provided on the closed lid 24. 27 is attached through the wall surface of the sealing lid 24.

A holding member 28 for holding a cassette C containing wafers is provided in the closed chamber 16, and the holding member 28 is reciprocally moved in the vertical direction to be held by the holding member 28. The raising / lowering drive mechanism for moving the cassette C up and down between the position above the cleaning tank shown by the two-dot chain line and the position inside the cleaning tank shown by the solid line is a closed chamber 1.
It is attached to 6. The lifting drive mechanism includes a drive rod 30 whose upper end is connected to the holding member 28, and the drive rod 3.
Bearing device 32 and drive pulley 34 for slidably supporting 0
And a driven pulley 36, a belt 38 that is stretched between the pulleys 34 and 36, and a lower end portion of the drive rod 30 is fixed to the belt 38,
And a drive motor 4 for rotating the drive pulley 34.
It consists of zero. The cassette C may be omitted by directly holding a plurality of wafers by the holding member 28.

At the pure water supply port 18 of the cleaning tank 12, there are provided pure water supply pipes 42 which are connected to a pure water supply source.
6, an air opening / closing valve 48, a filter device 50, and a ball valve 52 are provided in the pure water supply pipe line 42. Further, a pure water return conduit 54 is branched and connected in the middle of the pure water supply conduit 42, and an air opening / closing valve 56 is provided in the pure water return conduit 54. The pure water supply port 18 of the cleaning tank 12 has a pure water supply line 42.
Separately from the above, it is connected to a pure water discharge conduit 58 branched from the conduit 44, and the pure water discharge conduit 58 is connected to a drain via a conduit 60. On the other hand, a drainage port 62 is formed in the overflow water receiving portion 14, and a drainage pipe 66 is connected to the drainage port 62 via a pipe 64.
6 merges with the pure water discharge conduit 58 and is connected to the drain via the conduit 60. Pure water discharge line 58 and drain line 66
Air opening / closing valves 68 and 70 are respectively installed in the above.

Further, the pure water supply port 18 of the cleaning tank 12 is
The exhaust port 72 of the overflow water receiving portion 14 is connected to a vacuum exhaust pipe line 72 branched from the pipe line 46, while being connected to a vacuum exhaust pipe line 74 branched from the pipe line 64. An air opening / closing valve 7 is provided in each vacuum exhaust pipe line 72, 74.
6, 78 are provided respectively, and both vacuum exhaust pipe lines 7
2, 74 merge and are connected to a water-sealed vacuum pump 82 via a vacuum exhaust pipe 80. Reference numeral 84 in the figure denotes a ball valve provided in the vacuum exhaust pipe line 80.

Further, the vapor supply port 26 of the closed chamber 16
Include an inert gas such as nitrogen (N _Two) As a gas source
The steam supply pipe line 86 connected in communication is connected in communication.
The steam supply pipe 86 has an air opening / closing valve 88 and a heater.
90, alcohol vapor generation unit 92 and filter
-94 is installed. Alcohol vapor generation unit
In 92, methyl alcohol, ethyl alcohol, IP
Vapors of alcohols such as A are generated. In addition,
In addition to alcohols, it is water-soluble and can be used as a substrate
Organic solvent that has the effect of lowering the surface tension of pure water
As agents, ketones such as acetone and diethyl ketone, and
Ethers such as chill ether, ethyl ether, etc.
It is also possible to use polyhydric alcohols such as glycol
Yes, but products with low content of impurities such as metals are on the market
IPA is used because it is provided to
Most preferably. This alcohol vapor generation unit
As a method of generating alcohol vapor in
Bubbling, a method of blowing an inert gas into the rucoal
Use an appropriate method such as
You can do it. In addition, alcohol vapor generation unit
The hood 92 has a temperature control function to control the temperature to a specified level.
So that the alcohol vapors that are squeezed are produced
It Further, in the middle of the steam supply pipeline 86, air
-Bran off in the section between the on-off valve 88 and the heater 90
Between the steam generating unit 92 and the filter 94
A branch pipe 95 that joins between the two is provided.
An ionizer 96 and an air opening / closing valve 98 are provided in the pipe 95.
It is set up. And the state that the air opening / closing valve 88 is open
The nitrogen gas sent from the nitrogen gas supply source is heated by the heater 90.
Heated by the heated nitrogen gas,
Alcohol steam generated in the rucor steam generation unit 92
Qi is sent through the steam supply line 86 to vaporize alcohol.
The air is cleaned by the filter 94 together with the nitrogen gas.
Then, it is supplied to the closed chamber 16 through the steam supply port 26.
It is configured to be supplied. In addition, the air open / close valve 98
When opened, the heater 90 is fed from the nitrogen gas supply source.
The nitrogen gas heated by the ionizer 96
Ionized, its heated and ionized fill
The nitrogen gas cleaned by the tar 94 to the steam supply port 2
Can be fed into the closed chamber 16 through 6
Is also becoming.

Further, in this apparatus, the rubber heater 25 is controlled based on the detection signal of the thermometer 27 so that the temperature of the inner wall surface of the closed chamber 16 is maintained at a predetermined temperature, for example, the temperature of hot pure water for a desired period. A controller 100 is provided for this purpose.

Next, an example of a method for cleaning and drying a substrate, for example, a silicon wafer, using the substrate cleaning / drying apparatus having the above-described structure will be described.

First, the air opening / closing valves 48, 70 are opened, and the other air opening / closing valves 56, 68, 76, 78, 88,
With 98 closed, from the pure water supply source to the pure water supply pipe 42
By supplying pure water, for example, warm pure water through the pipes 46 and 44 and continuously supplying warm pure water into the cleaning tank 12 from the pure water supply port 18 at the bottom thereof, an ascending flow of warm pure water is supplied into the cleaning tank 12. Form. At this time, the warm pure water filling the inside of the cleaning tank 12 overflows from the overflow portion 20 at the upper part thereof, flows into the overflow water receiving portion 14, and the overflow water receiving portion 14
Through the drainage port 62, the drainage pipeline 66 and the pipeline 60, and is discharged to the drain. At the same time, the rubber heater 25 heats the wall surface of the closed chamber 16. In this heating, the controller 100 controls the rubber heater 25 based on the detection signal of the thermometer 27 attached to the wall surface of the closed lid 24, and the temperature of the inner wall surface of the closed chamber 16 is a predetermined temperature, for example, the temperature of hot pure water ( As an example, it is performed so as to be maintained at 60 ° or more. By heating the inner wall surface of the closed chamber 16 in this way, dew condensation of water vapor does not occur on the inner wall surface of the closed chamber 16 during the wafer cleaning process and the process of pulling the wafer from hot pure water, which will be described later. When the alcohol vapor is supplied to the periphery of the wafer, it is prevented that the thermal energy of the vapor is taken away by the condensed water droplets, and the wafer drying efficiency is improved. Then, the plurality of wafers contained in the cassette C are carried into the closed chamber 16 through the opening 22, and the closed lid 24 is hermetically closed.

Next, the elevating and lowering drive mechanism is operated to lower the cassette C held by the holding member 28 to the position indicated by the solid line in FIG. 2, so that the wafer is immersed in the warm pure water in the cleaning tank 12.
The wafer is cleaned by placing it in a rising stream of warm pure water for a predetermined time. This removes particles from the surface of the wafer. Then, the particles removed from the wafer surface and diffused into the warm pure water are discharged from the cleaning tank 12 together with the warm pure water overflowing from the overflow portion 20 above the cleaning tank 12.

When the cleaning of the wafer is completed, the elevating drive mechanism is operated to raise the cassette C held by the holding member 28 to the position shown by the chain double-dashed line in FIG. Pull up from inside. Since the wafer is raised in this way and pulled out from the warm pure water, the particles diffused in the warm pure water do not reattach to the surface of the wafer. Then, at the same time when the wafer is pulled up from the warm pure water, the air opening / closing valve 88 is opened, nitrogen gas is sent from the nitrogen supply source through the steam supply pipe line 86, and alcohol vapor is supplied from the vapor supply port 26 into the closed chamber 16. Alcohol vapor is supplied to the periphery of the wafer being fed and being pulled out of the hot pure water. This alcohol vapor supply is
The process is repeated until the wafer is completely lifted from the warm pure water. The air opening / closing valve 88 is opened before the start of pulling the wafer from the hot pure water so that alcohol vapor is supplied into the closed chamber 16, and the pure water interface is filled with the alcohol vapor at the start of pulling the wafer from the hot pure water. It is also possible to leave it in the state where it is set. Further, when the supply of the alcohol vapor to the periphery of the wafer is started, the heating operation of the wall surface of the closed chamber 16 by the rubber heater 25 is completed. Of course, subsequently, the wall surface of the closed chamber 16 may be heated until the wafer is completely dried.

Before the air opening / closing valve 88 is opened to supply alcohol vapor into the closed chamber 16, the air opening / closing valve 98 is opened so that the nitrogen gas heated from the nitrogen supply source through the branch pipe 95 (is ionized). Need not be)
Is preferably fed into the closed chamber 16 and the filter 94 is heated. Further, in parallel with supplying the alcohol vapor into the closed chamber 16 by opening the air opening / closing valve 88, the air opening / closing valve 98 is also opened to send the heated and ionized nitrogen gas into the closed chamber 16. Good. By sending the heated and ionized nitrogen gas into the closed chamber 16 as described above, a large amount of static electricity is generated in the closed chamber 16 because the closed chamber 16 is made of a corrosion resistant material and has an insulator structure. 2 to 10 kV), the static electricity is electrically neutralized by the ionized nitrogen gas and disappears. Therefore, particles are effectively prevented from adhering to the surface of the wafer due to static electricity.

When the wafer is lifted from the hot pure water, the air on-off valve 48 is closed and the air on-off valve 5 is closed.
6 is opened to stop the supply of warm pure water to the cleaning tank 12,
At the same time, the air on-off valve 68 is opened to discharge the hot pure water in the cleaning tank 12 to the drain through the pure water discharge conduit 58 and the conduit 60. When the discharge of the hot pure water from the cleaning tank 12 is finished, the air on-off valve 68, Close 70. Further, at the same time when the hot pure water is discharged from the cleaning tank 12, the air opening / closing valve 76,
By opening 78 and operating the water-sealed vacuum pump 82, the inside of the closed chamber 16 is evacuated through the respective vacuum exhaust pipe lines 72, 74 and the vacuum exhaust pipe line 80 to bring the closed chamber 16 into a reduced pressure state. Then, the alcohol condensed on the surface of the wafer and replaced with pure water is evaporated to dry the wafer. It should be noted that at the time when the pulling of the wafer from the hot pure water is completed and the depressurizing operation in the closed chamber 16 is started, the air opening / closing valve 88 is closed to stop the supply of the alcohol vapor into the closed chamber 16. Even when the pressure in the closed chamber 16 is reduced, a small amount of alcohol vapor may be continuously supplied into the closed chamber 16. Also, the closed chamber 1
The depressurizing operation in 6 and the supplying operation of the alcohol vapor into the closed chamber 16 may be alternately repeated.

When the wafer is completely dried, the vacuum pump 8
2 is stopped so that the pressure in the closed chamber 16 is returned from the reduced pressure to the atmospheric pressure. As described above, when the heated and ionized nitrogen gas is fed into the closed chamber 16 in parallel with supplying the alcohol vapor into the closed chamber 16, the wafer is dried under reduced pressure. A small amount of heated and ionized nitrogen gas is continuously supplied to the closed chamber 16 until the end of the above, and the inside of the closed chamber 16 is also returned until the inside of the closed chamber 16 is returned to the atmospheric pressure after the completion of the drying of the wafer. You may make it supply the heated nitrogen gas (it does not need to be ionized). Then, finally, the air on-off valve 98 is closed to stop the supply of the nitrogen gas to the closed chamber 16, the closed lid 24 is opened, and the cassette C containing the wafer after the cleaning / drying process is opened 22. Through the sealed chamber 16
Taken out.

FIG. 3 shows a time chart in the series of wafer cleaning / drying processing steps described above.

It should be noted that pure water may be used instead of hot pure water for cleaning the substrate in the cleaning tank. Further, as means for heating the wall surface of the closed chamber, instead of the rubber heater as shown in the above description and drawings,
A UV lamp or the like may be used.

[0031]

Since the present invention is constructed and operates as described above, when the substrate cleaning / drying processing apparatus according to the present invention is used, particles once removed from the surface of the substrate by cleaning are transferred to the substrate surface. It is possible to almost eliminate redeposition, and to quickly dry the substrate surface without particularly heating the substrate, improving work efficiency in a series of cleaning and drying processes. Also, the amount of organic solvent used for the drying process can be reduced. Then, the vapor of the organic solvent generated by the vapor generating means is cleaned by the filter and then sent into the closed chamber to be used for drying the substrate, so that the substrate is kept clean.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an example of an embodiment of the present invention and showing an overall configuration of a substrate cleaning / drying processing apparatus.

FIG. 2 is a side sectional view showing a configuration of a cleaning / drying processing unit of the apparatus shown in FIG.

FIG. 3 is a diagram showing an example of a time chart in a series of wafer cleaning / drying processing steps using the apparatus according to the present invention.

[Explanation of symbols]

10 Cleaning / Drying Processing Section 12 Cleaning Tank 14 Overflow Water Receiving Section 16 Sealed Chamber 18 Pure Water Supply Port 20 Overflow Section 24 Sealing Lid 25 Rubber Heater 26 Steam Supply Port 27 Thermometer 28 Holding Member 30 Driving Rod 38 Belt 40 Driving Motor 42 Pure water supply pipeline 48, 56, 68, 70, 76, 78, 88 Air opening / closing valve 58 Pure water discharge pipeline 62 Drain port 66 Drain pipeline 72, 74, 80 Vacuum exhaust pipeline 82 Water-sealed vacuum Pump 86 Steam supply line 90 Heater 92 Alcohol vapor generation unit 94 Filter 100 Controller

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 3B201 AA02 AA03 AA46 AB03 BB02                       BB11 BB82 BB88 BB93 BB95                       BC01 CB01 CC11 CC12                 3L113 AA01 AB02 AC08 AC23 AC28                       AC29 BA34 DA04

Claims (7)

[Claims] 1. A substrate is washed by immersing the substrate in pure water contained in a cleaning tank, and the substrate after cleaning is contained in a closed chamber having a substrate accommodation space above the cleaning tank. And a drying / drying processing unit for drying the substrate with the vapor of the organic solvent, a vapor generating unit for heating the organic solvent to generate the vapor of the organic solvent, and a vapor of the organic solvent generated by the vapor generating unit. Cleaning and drying of a substrate, comprising: a filter to be cleaned; and a vapor feeding means for feeding the vapor of the organic solvent generated by the vapor generating means and purified by the filter into the closed chamber. Processing equipment. 2. The substrate cleaning / drying apparatus according to claim 1, further comprising heating means for heating the closed chamber, wherein vapor of an organic solvent is fed into the closed chamber heated by the heating means. The substrate cleaning / drying processing apparatus is characterized in that the vapor of the organic solvent cleaned by the filter is heated by the above. 3. The substrate cleaning / drying apparatus according to claim 1 or 2, wherein the vapor supply means is provided with an inert gas supply source, the vapor generation means and the filter respectively. An apparatus for cleaning and drying a substrate, which is a gas supply means for supplying an inert gas together with the vapor of an organic solvent into the closed chamber through the above-mentioned pipeline. 4. The substrate cleaning / drying apparatus according to claim 3, further comprising gas heating means for heating the inert gas sent from the inert gas supply source to the vapor generating means by the gas supply means. A substrate cleaning / drying treatment device characterized by being provided. 5. The substrate cleaning / drying apparatus according to claim 3 or 4, wherein the vapor generating unit blows an inert gas into the organic solvent to generate vapor of the organic solvent. Substrate cleaning and drying processing equipment. 6. The substrate cleaning / drying processing apparatus according to claim 1, wherein the vapor generating unit has a temperature control function and vapor of an organic solvent adjusted to a predetermined temperature. An apparatus for cleaning and drying a substrate, which is characterized in that: 7. The substrate cleaning / drying apparatus according to claim 1, wherein before the vapor of the organic solvent is supplied into the closed chamber,
A substrate cleaning / drying apparatus characterized by heating the filter.