JP2000003899A - Method and device for processing substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain cleanliness also with drying performance being kept at a high level in a processing method for drying a substrate by using solvent, by controlling the flow on the water surface in a water washing tank adequately in one direction. SOLUTION: A plurality of semiconductor substrates 2 are held on a long substrate holding tool 11 in the straight standing state at the specified pitch and lifted to a drying chamber 4 from a water washing tank 3 by the lifting operation of the substrate holding tool 11. Then, a pure-water supply means 14, which flows the water surface in one direction so as to be located lower than the water surface (f) in the vicinity of the water surface (f) at the upper part of the water washing tank 3, is provided. This pure-water supply means 14 is the flow control means, which forcibly forms the flow of the water surface in parallel with the plate surface of the substrate 2 in the vicinity where a Marangoni effect is generated in drying. Furthermore, an exhaust port 9 for overflow is provided around the water washing tank 3 so as to exhaust the pure water 6 overflowing from the water washing tank 3 by the supply of the pure water 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate processing method and apparatus for integrally cleaning and drying a substrate.
In particular, the present invention relates to a substrate processing method and a substrate processing apparatus suitable for drying a substrate such as a semiconductor substrate that has been wet-cleaned.

[0002]

2. Description of the Related Art Generally, in the manufacturing process of semiconductor devices, particles (fine particles), metal contamination, organic contamination, and the like attached in the manufacturing process accompanying the miniaturization and high integration of semiconductor devices cause the device yield and the like to decrease. The effect on properties is increasing. For example, particles cause oxide film breakdown voltage failure and short-circuit / connection of wiring, and metal contamination and organic contamination cause oxide film breakdown voltage failure and junction leak failure.

However, most of the manufacturing processes of LSIs (large-scale semiconductor integrated circuits) are sources of particles, metal impurities, and organic contaminations. It is necessary to keep the surface of the semiconductor substrate (ie, semiconductor wafer) clean throughout the process. Therefore, in each manufacturing process, a cleaning process of the semiconductor substrate is appropriately performed,
In particular, as a recent substrate cleaning method, a wet cleaning method has become mainstream from the viewpoints of miniaturization of devices, increase in diameter of semiconductor substrates, and cost reduction.

When a semiconductor substrate is subjected to wet cleaning, it is necessary to remove moisture from the surface of the substrate after the cleaning and to dry the semiconductor substrate. As one of the drying methods for this purpose, a so-called “spin drying method” is known, in which the water on the substrate surface is shaken off and dried using the centrifugal force of high-speed rotation. However, in the case of the spin drying method, it is difficult to control the adhesion of particles and the watermark (water stain), and thus, a sufficiently satisfactory drying performance has not been obtained in manufacturing a device using the advanced technology.

Therefore, as a method for improving the drying performance, there is known a steam drying method in which the water adhering to the substrate surface is replaced with a solvent for drying. In particular, isopropyl alcohol (hereinafter abbreviated as IPA) is used as a solvent. The used one is called "IPA vapor drying method".

[0006] However, in the case of the conventional IPA vapor drying method in which the semiconductor substrate after the wet cleaning is transferred to a drying chamber filled with IPA vapor and dried, the IPA vapor is dried.
The influence of the purity of the semiconductor substrate on the drying performance and the transfer of the semiconductor substrate in a wet state in the air may cause a watermark. Also, the IPA steam drying method
Since IPA is constantly heated and vaporized, the consumption of IPA is large, which is one of the causes of an increase in manufacturing cost.

Therefore, in recent years, the consumption of IPA is small, and the drying performance does not depend much on the purity of IPA.
In addition, the semiconductor substrate is immediately removed from the washing tank by an IPA atmosphere (I
A so-called "IPA pull-drying method" has been proposed in which the substrate transfer time in the atmosphere is substantially reduced to zero by pulling the substrate into PA vapor.

FIGS. 4A and 4B show a conventional substrate processing apparatus for drying the surface of a semiconductor substrate by an IPA pull-up drying method. FIG. 4A is a front view, and FIG. 4B is a side view.
The substrate processing apparatus 21 includes a semiconductor substrate 2 to be cleaned.
2 and a drying chamber 25 that is installed above the washing tank 23 and is filled with an IPA atmosphere (IPA vapor) 24. Wash tank 23
A lower pure water supply port 28 for supplying pure water (so-called ultrapure water) 27 into the washing tank 23 is provided at the lower center thereof, and pure water overflowed from the washing tank 23 is provided at the upper part. An outlet 29 for discharging is provided.
The overflowed pure water is supplied to the washing tank 2 through the discharge port 29.
Although not shown in the drawing, it is discharged to the outside through the space between the outer tank 3 and the outer tank 26.

On the other hand, the semiconductor substrate 22 is
A plurality of sheets are held at a predetermined pitch on the substrate, and immersed in pure water 27 in the washing tank 23 in this state.

In the substrate processing apparatus 21, the substrate holder 3
The plurality of semiconductor substrates 22 held at 0
The cleaning process is performed by the pure water 27 immersed in the pure water 27 therein and continuously supplied from the lower supply port 28 and overflowing from the upper part. When the cleaning process for the semiconductor substrate 22 is completed, the semiconductor substrate 22 is pulled up from the washing tank 23 together with the substrate holder 30. At this time, the inside of the drying chamber 25 is
, The semiconductor substrate 22 after cleaning is
It is pulled directly into the PA vapor 24.

When the semiconductor substrate 22 is pulled up into the IPA vapor 24, the water (pure water) attached to the semiconductor substrate 22 is directly replaced by IPA due to the surface tension of the liquid layer in which IPA is dissolved (IPA liquid layer). Is removed from the substrate surface. Accordingly, the semiconductor substrate 22 is dried without being exposed to the air, and thus the watermark can be eradicated. At this time, it is important to control the supply amount of IPA to the water surface f, the pulling speed of the substrate 22, and the flow velocity of the water surface f to optimal ones.

[0012]

However, in the conventional substrate processing apparatus 21, the supply amount of IPA and the parmella of the pulling speed of the semiconductor substrate (wafer) 22 are directly controlled, and the flow velocity v of the water surface f is lower. Water supply port 2
8 is controlled by an indirect method of controlling the supply amount of pure water 28. For this reason, the flow inside the washing tank 23 is hindered by the influence of the semiconductor substrate 22 and the substrate holder 30, and the flow v of the water surface f is difficult to be properly controlled. Since the concentration is difficult to control, the drying performance is reduced. Further, particles floating on the crosses in the vicinity of the water surface f between the substrates 22 are hard to be discharged out of the washing tank 23.
This was a major cause of adhesion to the surface of No. 2.

The deterioration of the drying performance will be further described with reference to FIGS. In drying using IPA, the so-called Marangoni effect is used. That is, as shown in FIG. 5, the semiconductor substrate 22 is subjected to IPA from pure water 27 in a washing tank.
Looking at the IPA concentration of the liquid layer in which IPA is dissolved when the liquid layer is pulled up to the drying chamber filled with the vapor 24, the IPA in the liquid layer region (I) attracted to the semiconductor substrate 22 by the surface tension. The dissolution concentration is higher than the IPA dissolution concentration in the water surface area (II). This area (I)
The difference between the IPA dissolution concentrations in the region (II) and the region (II) serves as a driving force to cause the Marangoni effect to flow water, and the moisture attached to the semiconductor substrate 22 is replaced with IPA and dried.

By the way, as shown in FIG. 6, when a plurality of semiconductor substrates 22 are arranged and held close to each other, the flow of the water surface between the semiconductor substrates 22 stagnates, so that the regions (I) and (II) ), The IPA dissolution concentration is made uniform,
The difference in concentration is eliminated, and the Marangoni effect is less likely to occur.
, And satisfactory drying cannot be obtained.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a substrate capable of maintaining a high level of drying performance of a substrate and a degree of cleaning of a substrate surface. A processing method and a substrate processing apparatus are provided.

[0016]

A substrate processing method according to the present invention is a processing method for drying a substrate pulled up from a washing tank using a solvent, wherein the flow of the water surface of the washing tank is appropriately adjusted in one direction. Control.

In this substrate processing method, by forming a uniform one-way flow on the water surface, particles near the water surface can be efficiently discharged out of the washing tank. Along with this, the number of particles floating near the water surface during the drying process is reduced, the particles are suppressed from adhering to the substrate surface, and the degree of cleaning of the substrate surface can be maintained. In addition, the concentration of the solvent that dissolves on the water surface is appropriately controlled,
That is, the solvent concentration difference is maintained, the Marangoni effect is maintained, and high drying performance can be maintained.

A substrate processing apparatus according to the present invention is a substrate processing apparatus for drying a substrate pulled up from a washing tank by using a solvent, wherein the water surface of the washing tank flows in one direction.

In this substrate processing apparatus, the substrate processing method can be carried out by flowing the water surface of the washing tank in one direction, and particles near the water surface can be efficiently discharged. Accordingly, the number of particles floating near the water surface during drying is reduced, the particles are prevented from adhering to the substrate surface, and the cleanliness of the substrate surface is maintained. In addition, the concentration of the solvent dissolved in the water surface is appropriately controlled, that is, the difference in the solvent concentration is maintained, the Marangoni effect is maintained, and the high drying performance is maintained.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION A substrate processing method according to the present invention is a substrate processing method for drying a substrate pulled up from a washing tank using a solvent, wherein a uniform one-way flow is applied to the water surface of the washing tank. Is formed, and the speed of the flow is controlled so as to be an appropriate speed.

That is, a flow on the water surface is forcibly made near the substrate where the Marangoni effect is generated so as to be parallel to the substrate. A substrate processing apparatus according to the present invention is a substrate processing apparatus that dries a substrate pulled up from a washing tank using a solvent, and includes a flow control unit that controls a flow in one direction below the water surface near the water surface of the washing tank. A configuration is provided.

A substrate processing apparatus according to the present invention is a substrate processing apparatus for drying a substrate pulled up from a washing tank using a solvent, and includes a washing tank optimized so that a water surface flows in one direction. For example, a configuration is provided in which a drain port for overflowing and draining water in only one direction is provided at an upper portion of the washing tank.

A substrate processing apparatus according to the present invention is a substrate processing apparatus for drying a substrate pulled up from a rinsing tank using a solvent, wherein a flow for controlling a unidirectional flow below the water surface near the water surface of the rinsing tank. In addition to the control means, a drain port for overflowing and draining water only in one direction above the washing tank is provided.

As the solvent, for example, isopropyl alcohol (IPA) and other water-soluble alcohols such as pentafluoride alcohol and a mixture of perfluoroheptane and trifluoroethanol can be used.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a first embodiment of a substrate processing apparatus (so-called substrate cleaning / drying apparatus) according to the present invention.
Is a cross-sectional view as viewed from the front, and FIG. 1B is a cross-sectional view as viewed from the side. The substrate processing apparatus 1 of the present embodiment includes a washing tank 3 for cleaning a substrate to be cleaned, for example, a semiconductor substrate (a so-called semiconductor wafer) 2, and a drying chamber 4 for drying the semiconductor substrate 2 after the cleaning. And are integrally formed.

The drying chamber 4 has a box-shaped hollow structure, and has a large opening at the lower end thereof, and is arranged in the vicinity of the water surface f of the washing tank 3 so as to be opposed to each other. Drying chamber 4
The inside is filled with a solvent atmosphere, for example, an IPA atmosphere (ie, IPA vapor) 5.

On the other hand, a washing tank 3 containing the semiconductor substrate 2
Is filled with pure water (ultra pure water) 6. This washing tank 3
The above-mentioned drying chamber 4 is installed in the upper part, that is, immediately above. A lower pure water supply port 8 is provided at a lower portion of the washing tank 3, and the pure water 6 is supplied from the lower pure water supply port 8 into the washing tank 3.
Is supplied. An overflow drain 9 is provided around the washing tank 3 to drain the pure water 6 overflowing from the washing tank 3 by the supply of the pure water 6. The overflowed pure water is discharged from the drain port 9 to the outside through the drain channel 10.

The semiconductor substrate 2 is an elongated substrate holder 11.
A plurality of sheets are held upright at a predetermined pitch and are lifted from the washing tank 3 to the drying chamber 4 by the raising operation of the substrate holder 11.

Then, the substrate processing apparatus 1 of the first embodiment
In particular, a pure water supply means 14 for flowing the water surface to one side is provided so as to be located near the water surface f above the water washing tank 3 and below the water surface f. The pure water supply means 14 is a flow control means for forcibly generating a flow on a water surface parallel to the plate surface of the substrate 2 in the vicinity where the Marangoni effect occurs during drying. The pure water supply means 14 forms a plurality of openings 13 a serving as pure water supply ports in one side surface of the long pure water supply pipe 13 extending in the arrangement direction of the semiconductor substrates 2 along the arrangement direction of the substrates 2. It is configured to supply a fixed amount of pure water from the opening 13a.

The pure water supply pipe 13 is disposed on one side of the washing tank 3 along the direction in which the semiconductor substrates 2 are arranged.
By supplying pure water from 3a, a uniform one-way flow, that is, a one-way flow v along the surface of the semiconductor substrate 2 is formed on the water surface f. Here, by controlling the flow rate from the opening 13a, the flow v of the water surface f, that is, the flow velocity can be optimally controlled.

In the substrate processing apparatus 1, pure water 6 is supplied from the lower pure water supply port 8 into the washing tank 3, and the pure water 6 overflows from the upper part and is held by the substrate holder 11. The semiconductor substrate 2 is immersed in pure water 6 in a washing tank 3 to perform a cleaning process on the semiconductor substrate 2. When the cleaning process is completed, the semiconductor substrate 2 is lifted from the washing tank 3 to the drying chamber 4 with the rise of the substrate holder 11.

The semiconductor substrate 2 is placed in the IPA of the drying chamber 4.
By being pulled up into the vapor 5, as described above, due to the surface tension of the IPA liquid layer in which IPA is dissolved,
The moisture (pure water) attached to the semiconductor substrate 2 is directly replaced with IPA and removed from the substrate surface, and the semiconductor substrate 2 is dried.

Then, the semiconductor substrate 2 is removed from the washing tank 3.
When the water is pulled up, the one-way flow v along the plate surface of the substrate 2 on the water surface f by the pure water supply from the opening 13a of the pure water supply pipe 13
Is generated, particles near the water surface f are discharged to the outside of the washing tank through the drain passage 10 together with the overflowing pure water in one direction. Accordingly, particles floating near the water surface f are reduced, and particles are prevented from adhering to the surface of the semiconductor substrate 2.
The degree of cleaning of the surface can be maintained.

The water surface f between each adjacent semiconductor substrate 2
Is forced to flow in one direction without stagnation, so that the concentration of the solvent dissolved in the water surface f, ie, in this example, IP
The A concentration is appropriately controlled, the IPA concentration difference between the region (I) and the region (II) described with reference to FIG. 6 is maintained, the Marangoni effect is maintained, and high drying performance can be maintained.

FIG. 2 shows a second embodiment of the substrate processing apparatus according to the present invention.
1 shows an embodiment. In the second embodiment,
The same components as those in the above-described first embodiment are denoted by the same reference numerals, and redundant description will be omitted.

The substrate processing apparatus 15 according to the second embodiment comprises:
As in FIG. 1, a washing tank 3 for washing, for example, a semiconductor substrate 2 to be washed, and a drying chamber 4 are integrally provided. The drying chamber 4 has a box-shaped hollow structure, a lower end portion of which is largely open, and a water surface f of the washing tank 3.
Are arranged in a facing state in the vicinity of. The drying chamber 4 is filled with, for example, IPA vapor 5 as a solvent atmosphere.

On the other hand, a washing tank 3 containing the semiconductor substrate 2
Is filled with pure water (ultra pure water) 6, and the drying chamber 4 is installed above (directly above). The washing tank 3 is formed so that the pure water 6 is supplied from the lower pure water supply port 8 and the pure water 6 overflows from the upper part. A plurality of semiconductor substrates 2 are held upright on a long substrate holder 11 at a predetermined pitch at a predetermined pitch, and are lifted from the washing tank 3 to the drying chamber 4 by the raising operation of the substrate holder 11. .

Then, the substrate processing apparatus 15 of the second embodiment
In particular, as an optimized washing tank, a drain port 9 for overflow is provided only on one side of the upper part of the washing tank 3, and the pure water supplied from the lower pure water supply port 8 and overflowing from the washing tank 3 is provided. The water 6 is configured to be drained to the outside of the washing tub 3 through a drainage channel 10 from an outlet 9 on one side.

The drain port 9 is provided on one side along the arrangement direction of the semiconductor substrates 2 housed in the washing tank 3. The outlet 9 forms a uniform one-way flow on the water surface f, that is, a one-way flow v along the plate surface of the semiconductor substrate 2. The flow velocity of the water surface f can be optimally controlled by the flow rate from the lower pure water supply port 8.

In the substrate processing apparatus 15, pure water 6 is supplied into the washing tank 3 from the lower pure water supply port 6, and pure water 6 is supplied from the upper part.
The semiconductor substrate 2 held by the substrate holder 11 is immersed in pure water 6 in the washing tank 3 in a state of overflowing to perform a cleaning process.

When the cleaning process is completed, the semiconductor substrate 2 is moved from the washing tank 3 to the drying chamber 4 as the substrate holder 11 is raised.
Into the IPA vapor. Thereby, the moisture adhering to the semiconductor substrate 2 is replaced with IPA and removed from the substrate surface, and the semiconductor substrate 2 is dried.

When the semiconductor substrate 2 is lifted,
The pure water 6 is supplied from the lower pure water port 8, overflows from the upper part of the washing tank 3, and is discharged toward the drain port 9 provided only on one side of the washing tank 3. One-way flow along the plate surface occurs. The flow of the water surface f can be optimally controlled by the flow rate from the lower pure water supply port 8.

Therefore, as in the first embodiment, it is possible to simultaneously maintain the cleaning degree of the semiconductor substrate 2 and improve the drying performance.

FIG. 3 shows a third embodiment of the substrate processing apparatus according to the present invention.
1 shows an embodiment. The same components as those in the above-described first embodiment and the second embodiment are denoted by the same reference numerals, and redundant description will be omitted.

The substrate processing apparatus 17 according to the third embodiment
In particular, similarly to the above-described first embodiment, so that it is located below the water surface f near the water surface f in the upper part of the washing tank 3,
A pure water supply means 14 for flowing the water surface in one direction is provided, and one side of the upper part of the washing tank 3, that is, a side where the pure water supply means 14 is provided, as shown in the second embodiment. Only the opposite side is provided with an overflow drain 9. Other configurations are the same as those in FIGS.

According to the substrate processing apparatus 17, it is possible to form an optimal one-way flow on the water surface f by the interaction between the pure water supply from the pure water supply means 14 and the outlet 9 on one side. As a result, it is possible to simultaneously maintain the degree of cleaning and improve the drying performance as in the first and second embodiments.

In the first, second, and third embodiments, examples of application to the substrate processing apparatus for cleaning and drying the semiconductor substrate 2 have been described. However, the present invention is not limited to this. The present invention can be similarly applied to a substrate processing apparatus for cleaning and drying a liquid crystal glass substrate, an optical disk, a magnetic disk, and the like.

[0049]

According to the substrate drying method of the present invention, by forming a one-way flow on the water surface of the washing tank and controlling the speed of the flow, particles near the water surface can be efficiently removed from the washing tank. And the particles floating near the water surface during the drying process can be reduced.
Therefore, adhesion of particles to the substrate surface can be suppressed, and the degree of cleaning of the substrate surface can be maintained. In addition, since the concentration of the solvent that dissolves on the water surface is appropriately controlled,
High drying performance can be maintained.

According to the substrate processing apparatus of the present invention, by providing the flow control means below the water surface near the water surface in the washing tank, a uniform one-way flow can be created on the water surface. A substrate processing method can be performed.

Further, according to the substrate processing apparatus of the present invention, a uniform one-way flow can be created on the water surface by providing a drain port for overflowing in one direction only in the upper part of the washing tank. Then, the substrate processing method of the present invention can be performed.

Further, according to the substrate processing apparatus of the present invention,
By arranging the flow control means below the water surface in the vicinity of the water surface in the washing tank, and having a drain port that overflows only in one direction at the top of the washing tank, a uniform one-way flow on the water surface is provided. And the substrate processing method of the present invention described above can be performed.

Therefore, according to the above-described substrate processing apparatus of the present invention, particles near the water surface can be efficiently discharged to the outside of the washing tank, and particles floating near the water surface during the drying treatment can be reduced, and the surface of the substrate can be reduced. It is possible to maintain the degree of cleaning of the substrate surface by suppressing the attachment of particles. In addition, the concentration of the solvent dissolved in the water surface can be appropriately controlled, and high drying performance can be maintained.

[Brief description of the drawings]

FIG. 1A is a cross-sectional view of a first embodiment of a substrate processing apparatus according to the present invention, as viewed from the front. B It is sectional drawing seen from the side shown by this invention.

FIG. 2 is a sectional view of a substrate processing apparatus according to a second embodiment of the present invention, as viewed from the front.

FIG. 3 is a front sectional view showing a third embodiment of the substrate processing apparatus according to the present invention.

FIG. 4A is a cross-sectional view of a conventional substrate processing apparatus as viewed from the front. It is sectional drawing seen from B side.

FIG. 5 is an explanatory diagram for explaining a problem when drying using a solvent.

FIG. 6 is an explanatory diagram for explaining a problem when drying using a solvent.

[Explanation of symbols]

1,15,17 substrate processing device, 2 semiconductor substrate,
3 washing tank, 4 drying chamber, 5 IPA steam, 6 pure water, 8 lower pure water supply port, 9 drain port, 11 substrate holder, 13 pure Water supply pipe, 13a
{Opening, 14} Pure water supply means (flow control means)

Claims (4)

[Claims] 1. A substrate processing method for drying a substrate pulled up from a washing tank by using a solvent, wherein a one-way flow is formed on a water surface of the washing tank, and a speed of the flow is controlled. A substrate processing method characterized by the above-mentioned. 2. A substrate processing apparatus for drying a substrate lifted from a washing tank using a solvent, comprising a flow control means for controlling a flow in one direction below a water surface near a water surface of the washing tank. A substrate processing apparatus comprising: 3. A substrate processing apparatus for drying a substrate lifted from a washing tank by using a solvent, comprising a drain port for overflowing in one direction only in an upper part of the washing tank to drain the substrate. A substrate processing apparatus characterized by the above-mentioned. 4. The substrate processing apparatus according to claim 2, further comprising a drain port for overflowing and draining in only one direction at an upper portion of the washing tank.