KR20080046329A - Apparatus and method for drying substrate - Google Patents

Abstract

An apparatus and a method for drying a substrate are provided to stabilize the surface of a rinsing liquid by performing the drying in a decompressed state. A vacuum chamber(10) has a cover which can be closed and opened. A drying bath(20) for receiving a plurality of substrates is mounted at the lower part of the vacuum chamber. A pipeline(80) is disposed at the bottom end of the drying bath, and supplies a rinsing liquid into the drying bath uniformly. A vacuum pump(30) decompress a pressure of the inside of the vacuum chamber so as to prevent the shaking of the surface of the rinsing liquid.

Description

Apparatus and method for drying substrate

1 is a cross-sectional view of a substrate drying equipment according to the present invention.

2 is a top side view of the substrate drying equipment according to the present invention.

3 is a side view of the substrate drying equipment according to the present invention.

* Description of symbols on the main parts of the drawings *

10: vacuum chamber 60: infrared lamp

15: cover 70: flow meter for adjusting the ozone gas supply

20: dry bath 80: rinse liquid supply piping

30: vacuum pump 90: drain valve

40: vacuum valve 100: substrate drying apparatus

50: substrate lift

The present invention relates to an apparatus and method for drying a substrate after cleaning the substrate, and more particularly, to a substrate drying apparatus and method for completely drying a substrate such that watermarks and particles are not generated. It is about.

In general, many cleaning processes are performed in semiconductor substrate manufacturing and device manufacturing processes. This cleaning process removes contaminants such as particles, metallic impurities, and native oxides generated in the previous process.The cleaning process is filled with a cleaning tank, and then the substrate is placed in the cleaning solution to remove these contaminants. It is first removed and then rinsed using pure water. After the cleaning process, a drying process is performed, and watermarks or particles may remain in the drying process. As the semiconductor substrates are large-sized, it is more important to prevent watermarks or particles from occurring on the outer surface of the substrate when the substrate is dried.

Conventionally, a kimmon dryer has been widely used as a drying apparatus for finally treating a substrate surface after a cleaning process. The drying method using the Kimon dryer is as follows. The organic solvent having a volatility such as isopropyl alcohol (IPA) is heated to 200 ° C. or more to vaporize it. Pure water or moisture present on the surface of the substrate is replaced with this vapor and moisture removal and drying are performed using heated nitrogen (hot N ₂ ). However, such a Chimon dryer has a problem of fire because the substrate is dried by heating flammable organic solvent to a high temperature.

In order to solve the above problems, the marangoni drying method using the surface tension of the liquid has been conventionally designed.

In the Marangoni drying method, the first step is to immerse the substrate in pure water in a liquid bath in the drying chamber, and supply vapor of organic solvent such as isopropyl alcohol vapor to the pure surface and surroundings through the steam pipe. The pure water is discharged through the drain valve of the drain pipe in order to expose the substrate submerged in the pure water while continuously supplying the vapor of the organic solvent. At this time, instead of draining the pure water, a method of moving the substrate onto the pure water surface may be used.

At this time, the vapor of the organic solvent is condensed or dissolved on the pure water surface to form one liquid layer. The difference in the surface tension of the two liquid layers acting on the liquid layer and the pure interface acts as a force to remove moisture on the surface of the substrate while preventing the particles from re-adhering on the surface of the substrate passing through this interface.

Since the marangoni drying method requires the substrate to be dried on the surface of the water, the surface of the water must be maintained for a stable process. However, it is very difficult to prevent the fluctuation of the surface due to the drainage of pure water. There was a problem that it was easy to do. In addition, the marangoni drying method has a lower temperature of isopropyl alcohol than that of a Kimmon dryer. However, since the ignition point of isopropyl alcohol is 22 ° C, there is also a risk of fire.

The present invention has been made to solve the above problems, an object of the present invention to provide a substrate drying equipment and method for forming a clean substrate surface by preventing the shaking of the surface of the rinse liquid and preventing the re-adsorption of particles. do.

In order to achieve the above object, the substrate drying equipment according to the present invention, the cover has a vacuum chamber capable of opening and closing the inlet, a drying bath mounted on the lower portion of the vacuum chamber to accommodate a plurality of substrates, the bottom of the drying bath And a piping for uniformly supplying the rinse liquid into the drying bath, and a vacuum pump for reducing the pressure inside the vacuum chamber to prevent water fluctuations of the rinse liquid supplied into the drying bath. It is done.

In this case, the substrate drying equipment may further include a substrate lift for lifting the substrate.

In addition, the substrate drying equipment may further include an infrared lamp for promoting the drying of the substrate, in particular the infrared lamp may be mounted on at least one of the cover of the vacuum chamber or the outer wall of the vacuum chamber. .

In addition, the substrate drying equipment may further include a flow meter for adjusting the ozone gas supply for supplying ozone gas into the vacuum chamber.

Here, the rinse liquid may use ultrapure water or ozone water.

In addition, in order to achieve the above object, the substrate drying method according to the present invention is a substrate drying method using the above-described substrate drying equipment, the substrate is contained in a drying bath and rinsed by overflowing the rinse liquid inside the drying bath. Proceeding with the step of stopping the overflow of the rinse liquid when the rinse process is completed, the step of reducing the pressure inside the vacuum chamber to prevent the surface shake of the rinse liquid, the pressure inside the vacuum chamber is a constant pressure When it reaches to the substrate is characterized in that it comprises the step of slowly rising and drying the surface of the rinse liquid.

At this time, the substrate drying equipment further comprises an infrared lamp for promoting the drying of the substrate, and using the infrared lamp at the same time or after the step of gradually raising the substrate on the surface of the rinse liquid is completed The method may further include removing residual moisture of the substrate.

The method may further include recovering the atmospheric pressure while maintaining the atmosphere of the vacuum chamber at the same time as removing the remaining moisture of the substrate using the infrared lamp.

At this time, the substrate drying equipment further comprises a flow meter for adjusting the ozone gas supply for supplying ozone gas into the vacuum chamber, and at the same time or after the step of gradually raising the substrate on the surface of the rinse liquid The method may further include injecting the ozone gas into the vacuum chamber.

In addition, by injecting the ozone gas to form an ultra-clean thin protective oxide film on the surface of the substrate, it is possible to prevent the re-adsorption of particles after drying.

Here, the predetermined pressure may be 600 torr to 760 torr.

In addition, the rinse liquid may use ultrapure water or ozone water.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various different forms, and only the embodiments will make the disclosure of the present invention complete and fully understand the scope of the invention to those skilled in the art. It is provided to give. Like numbers refer to like elements throughout.

Substrate which can use the substrate drying equipment and the substrate drying method according to the present invention includes a silicon wafer substrate, such as LCD, PDP, LED, as well as a device substrate such as an IC chip or a mechanism with a logic circuit or data storage element All of them can be applied, and in the following embodiment, a silicon wafer substrate is described as an example.

1 is a cross-sectional view of a substrate drying equipment according to the present invention, Figure 2 is a side view of the substrate drying equipment according to the present invention, Figure 3 is a side view of the substrate drying equipment according to the present invention.

1 to 3, the substrate drying equipment 100 according to the present invention includes a vacuum chamber 10, a lid 15, a drying bath 20, a vacuum pump 30, a vacuum valve 40, and a substrate. The elevator 50, the infrared lamp 60, the flow meter 70 for ozone gas supply adjustment, the rinse liquid supply pipe 80, and the drain valve 90 are provided.

The vacuum chamber 10 has the cover 15 is designed to open and close the inlet. The drying bath 20 may be mounted under the vacuum chamber 10 to accommodate a plurality of wafers W, and the vacuum pump 30 and the vacuum valve 40 may be disposed inside the vacuum chamber 10. It serves to reduce the pressure. The substrate lifter 50 serves to lift and lower the wafer W in the vacuum chamber 10. The infrared lamp 60 is mounted on the cover 15 of the vacuum chamber 10 or the outer wall of the vacuum chamber 10 to facilitate drying of the wafer W. The ozone gas supply control flow meter 70 supplies ozone gas into the vacuum chamber 10. The rinse liquid air raid pipe 80 is located at the bottom of the drying bath 20 to uniformly supply the rinse liquid into the drying bath 20, and the drain valve 90 is responsible for draining the rinse liquid. do.

Referring to the substrate drying method using the substrate drying equipment 100 as described above are as follows.

First, the lid 15 of the vacuum chamber 10 is opened, and the wafer W, which has been cleaned, is charged into the drying bath 20 mounted under the vacuum chamber 10. In this case, the drying bath 20 may use a quartz bath.

The rinse liquid is uniformly supplied into the drying bath 20 through the rinse liquid supply pipe 80. At this time, the method of supplying the rinse liquid adopts a so-called overflow method which is supplied from the lower end of the drying bath 20 and discharged to the upper end.

The rinse liquid overflowing the drying bath 20 is drained out of the vacuum chamber 10 by opening the drain valve 90. Then, the lid 15 of the vacuum chamber 10 is closed and the rinse proceeds while continuing to overflow the rinse liquid.

Here, the rinse liquid may use ultra-pure water or ozone water, which is water of high purity with as little impurities as possible, or ozone water. In this case, the ultrapure water may be used at room temperature up to 80 ° C.

When the rinse is completed after a certain period of time, in order to stop the overflow of the rinse liquid, the rinse liquid supply pipe 80 is closed and the vacuum valve 40 is opened to open the inside of the chamber 10 using the vacuum pump 30. Relieve the pressure. At this time, the pressure inside the chamber 10 is maintained below atmospheric pressure, and preferably controlled between 600 Torr and 760 Torr.

When the pressure of the vacuum chamber 10 is completed within the pressure range of 600 to 760 torr, the substrate W 50 is used to dry the wafer W while gradually raising the surface of the rinse liquid.

This drying process is performed in the vacuum chamber 10, and the drying is performed in a reduced pressure inside the vacuum chamber 10, it is possible to achieve the stabilization of the surface of the rinse liquid. Accordingly, the surface of the rinse liquid may be prevented from being contaminated to prevent contamination of the wafer W, which may occur when the wafer W is gradually raised from the surface of the rinse liquid using the substrate lifter 50. Can be.

In addition, an infrared lamp 60 may be used to directly heat the wafer W to promote drying of moisture remaining on the surface of the wafer W. At this time, if the heating temperature of the wafer W using the infrared lamp 60 is too high, damage to the surface of the wafer W is caused, so that the calorific value of the infrared lamp 60 is appropriately adjusted.

Removing the moisture remaining on the surface of the wafer W using the infrared lamp 60 may be performed simultaneously with the step of gradually raising the wafer W from the surface of the rinse liquid. In addition, after the step of raising the wafer W on the surface of the rinse liquid is completed, the remaining moisture of the wafer W may be removed using the infrared lamp 60.

The infrared lamp 60 may be used to remove residual moisture of the wafer W, and at the same time, maintain the atmosphere of the vacuum chamber 10 in an ozone atmosphere, and recover the atmospheric pressure.

In addition, when exposed to the atmosphere after drying, ozone gas is supplied into the vacuum chamber 10 using the ozone gas supply control flow meter 70 to prevent readsorption of particles due to static electricity. Through ozone gas supply, a stable and ultra-clean thin ozone oxide film can be formed on the surface of the wafer (W).

At this time, the step of forming the ozone oxide film using the ozone gas supply control flow meter 70 may be simultaneously with the step of gradually raising the wafer (W) on the surface of the rinse liquid. Alternatively, after the step of raising the wafer W from the surface of the rinse liquid is completed, the ozone oxide layer may be formed by injecting the ozone gas into the vacuum chamber.

When the drying is completed through the above-described process, while maintaining the atmosphere of the vacuum chamber 10 in an ozone atmosphere, the pressure inside the vacuum chamber 10 is restored to atmospheric pressure.

Then, the drying process using the substrate drying equipment and the substrate drying method of the present invention is completed by opening the lid 15 of the vacuum chamber 10 and taking out the wafer W.

In the above, the present invention has been described in detail with reference to preferred embodiments, but the present invention is not limited to the above embodiments, and various modifications are possible by those skilled in the art within the technical idea of the present invention. Is obvious.

According to the present invention, since drying is performed under a reduced pressure, the surface of the substrate may be prevented due to fluctuation of the surface because the surface of the rinse liquid may be stabilized without being affected by the external air flow.

In addition, an infrared lamp may be used to promote drying of the substrate during the drying process, and a ozone gas may be used to form a stable ozone oxide film on the surface of the substrate to perform hydrophilization. The hydrophilized substrate is safe because it prevents resorption of particles due to static electricity when exposed to the air after drying. In addition, the ozone oxide film has a strong adhesion with the substrate and the oxide film has a long duration, and thus the ozone oxide film can be maintained for a long time even when the wafer is transported.

In addition, according to the substrate drying equipment and method of the present invention, rinsing, drying (particularly drying using an infrared lamp) and substrate hydrophilization can be simultaneously performed in a single device for cleaning.

Claims (13)

A vacuum chamber having a cover to open and close the inlet; A drying bath mounted under the vacuum chamber to accommodate a plurality of substrates; A pipe positioned at a lower end of the drying bath to uniformly supply a rinse liquid into the drying bath; And Vacuum pump for reducing the pressure inside the vacuum chamber in order to prevent the surface shake of the rinse liquid supplied into the drying bath Substrate drying equipment comprising a. The method of claim 1, Substrate drying equipment further comprises a substrate lift for lifting the substrate. The method of claim 1, Substrate drying equipment further comprises an infrared lamp for promoting the drying of the substrate. The method of claim 3, And the infrared lamp is mounted on at least one of a cover of the vacuum chamber or an outer wall of the vacuum chamber. The method of claim 1, Substrate drying equipment further comprises a flow meter for adjusting the ozone gas supply for supplying ozone gas into the vacuum chamber. The method of claim 1, And the rinse liquid is ultrapure water or ozone water. As a substrate drying method using the substrate drying equipment according to claim 1, Storing the substrate in a drying bath and rinsing the rinse liquid by overflowing the inside of the drying bath; Stopping the overflow of the rinse liquid when the rinse process is completed; Depressurizing the inside of the vacuum chamber to prevent sleep fluctuations of the rinse liquid; And Slowly drying the substrate on the surface of the rinse liquid when the pressure inside the vacuum chamber reaches a predetermined pressure; Substrate drying method comprising a. The method of claim 7, wherein The substrate drying equipment further includes an infrared lamp for promoting drying of the substrate, And removing the remaining moisture of the substrate using the infrared lamp at the same time as the step of slowly raising the substrate from the surface of the rinse liquid or after the step of raising the rinse liquid is completed. The method of claim 8, And removing the residual moisture of the substrate by using the infrared lamp, and simultaneously restoring the atmosphere of the vacuum chamber to atmospheric pressure while maintaining the atmosphere of the vacuum chamber in an ozone atmosphere. The method of claim 7, wherein The substrate drying equipment further includes a flow meter for adjusting the ozone gas supply to supply ozone gas into the vacuum chamber, And injecting the ozone gas into the vacuum chamber simultaneously with the step of slowly raising the substrate at the surface of the rinse liquid or after the step of raising the substrate is completed. The method of claim 10, And injecting the ozone gas to form a super clean thin protective oxide film on the surface of the substrate to prevent resorption of particles after drying. The method of claim 7, wherein The predetermined pressure is 600 Torr to 760 Torr, characterized in that the substrate drying method. The method of claim 7, wherein The rinse liquid is a substrate drying method, characterized in that ultra-pure or ozone water.

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