JP3277367B2 - Substrate drying method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for drying a substrate, and more particularly, to a method for quickly drying a substrate that has been cleaned using a cleaning liquid.

[0002]

2. Description of the Related Art Conventionally, after cleaning a substrate (eg, a semiconductor wafer) using a cleaning liquid, a drying fluid vapor {eg, isopropyl alcohol (eg, As an apparatus for supplying a vapor such as｝ for drying a substrate, an apparatus having a configuration disclosed in Japanese Patent Publication No. 6-103686 has been proposed.

When this apparatus is used, a plurality of substrates accommodated in a processing tank are washed with a cleaning liquid, and then a drying fluid vapor is introduced into the processing tank while the liquid level of the cleaning liquid is lowered, whereby the cleaning liquid is introduced. A liquid layer of a thin drying fluid is formed on the liquid surface of the substrate, and the surface of the substrate can be dried quickly by utilizing the Marangoni effect.

[0004]

[Problems to be Solved by the Invention]
In the case of employing the apparatus having the configuration shown in Japanese Patent Application Laid-Open No. 6-106, not only the introduction flow path for introducing the drying steam but also the drying steam is discharged in order to form the flow of the drying steam in the processing tank. Although a relief valve (exhaust port) is required, a drying fluid is introduced into the central part of the substrate row accommodated in the processing tank in two rows. The direction of introduction of the drying fluid, the initial speed of introduction, and the like are not set at all.

Therefore, the substrate has a small diameter and / or
Alternatively, when the distance between the substrates is large, the drying fluid can be smoothly introduced into the gap between the substrates even when the direction of introduction of the drying fluid, the initial introduction speed, etc. are not set at all. It seems that fast and even drying can be achieved. However, when the diameter of the substrates is large and / or the distance between the substrates is small, the drying fluid cannot be smoothly introduced into the gaps between the substrates, resulting in drying unevenness and generation of a watermark. There are inconveniences such as doing.

When a semiconductor wafer is used as a substrate, the size of the semiconductor wafer is generally increased in recent years, and at the same time, the speed of processing such as cleaning and drying is increased (when a semiconductor wafer is converted into one wafer). With the increasing demand for high-speed processing, it is becoming common to reduce the spacing between semiconductor wafers in order to increase the number of semiconductor wafers that can be processed simultaneously. Therefore, in such a situation, the above-described inconvenience becomes significant.

As a method for alleviating the occurrence of such inconvenience, it is conceivable to increase the concentration of the supplied drying fluid (for example, to employ a high-concentration drying fluid vapor). Causes a new disadvantage that the consumption of the drying fluid increases and the running cost increases. Further, it is conceivable to increase the temperature of the supplied drying fluid (for example, to employ high-temperature drying fluid vapor). In this case, however, it is necessary to increase the temperature of the drying fluid vapor. As a result, the running cost similarly increases. In addition, since there is a limit in increasing the temperature of the vapor of the drying fluid, the substrate size and interval that can be dealt with by this method are limited.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and quickly and uniformly generates unevenness even when the size of the substrate is increased and / or the distance between the substrates is reduced. It is an object of the present invention to provide a substrate drying method capable of drying a plurality of substrates at the same time without drying.

[0009]

According to a first aspect of the present invention, there is provided a method for drying a substrate, wherein a plurality of substrates are accommodated in a processing tank, and a level of a cleaning liquid in the processing tank is lowered relative to the substrate. In drying the surface of the substrate by supplying the drying fluid into the processing tank, the direction of introduction of the drying fluid into the processing tank is such that the drying fluid spreads over the entire width of the substrate at the level of the cleaning liquid. Is set so that the drying fluid is directed toward the center of the substrate, and the initial introduction speed of the drying fluid is set based on the outer diameter of the substrates and the interval between the substrates.

[0010]

A second aspect of the present invention is a method of setting the initial introduction speed of the drying fluid based on the relative position between the substrate and the level of the cleaning liquid. The substrate drying method according to a third aspect is a method of supplying a drying fluid downward through a supply nozzle and corresponding to a gap between the substrates. According to the substrate drying method of the present invention, the drying fluid is supplied vertically downward through the supply nozzle and corresponding to the gap between the substrates, and the initial introduction speed corresponding to the central portion of the substrate corresponds to the peripheral portion of the substrate. This is a method of setting the initial speed higher than the initial speed. According to a fifth aspect of the present invention, in order to direct the drying fluid through the supply nozzle and near the center of the substrate corresponding to a gap between the substrates, the drying fluid is mutually based on a vertical plane passing through the centers of the plurality of substrates. This is a method of supplying the liquid diagonally downward. The substrate drying method according to claim 6, wherein the drying fluid is:
In order to pass vertically through the supply nozzle and corresponding to the gap between the substrates and toward the center of the substrate,
This is a method in which supply is performed obliquely downward and opposite to each other based on a vertical plane passing through the centers of a plurality of substrates, and the vertical initial introduction speed is set to be greater than the diagonally downward introduction initial speed.

[0012]

According to the substrate drying method of the present invention, a plurality of substrates are accommodated in a processing tank, and the level of a cleaning liquid in the processing tank is lowered while relative to the substrate. In drying the surface of the substrate by supplying the drying fluid, the direction of introduction of the drying fluid into the processing tank is adjusted so that the drying fluid spreads over the entire width of the substrate at the level of the cleaning liquid. Is set to the center of the substrate, and the initial speed of introduction of the drying fluid is set based on the outer diameter of the substrate and the interval between the substrates. Therefore, the direction of introduction and the initial speed of introduction are easily set. Even if the diameter of the substrate is increased and / or the distance between the substrates is reduced, the drying fluid can be smoothly supplied to the gap between the substrates.
The liquid phase of the drying fluid can be continuously formed on the liquid surface of the cleaning liquid, and thus the substrate can be dried quickly and evenly. Further, not only does it not be necessary to increase the concentration of the drying fluid more than necessary, it is not necessary to increase the temperature of the drying fluid more than necessary. When mixed with air due to its flammability, it has explosive properties, but this explosive property can be suppressed, which is also beneficial in terms of safety.

[0013]

According to the substrate drying method of the present invention, the initial velocity of the drying fluid is set based on the relative position between the substrate and the liquid level of the cleaning liquid. Accordingly, an optimum initial velocity can be set, and the same operation as in the first aspect can be achieved. According to the substrate drying method of claim 3, since the drying fluid is supplied downward through the supply nozzle and corresponding to the gap between the substrates, the drying fluid can be introduced into the gap between the substrates. The same operation as the first or second aspect can be achieved. According to the substrate drying method of the fourth aspect, the drying fluid is supplied vertically downward through the supply nozzle and corresponding to the gap between the substrates, and the initial introduction speed corresponding to the center of the substrate is set at the peripheral portion of the substrate. It is set to be higher than the initial velocity corresponding to, so it is easy to secure a sufficient spread of the drying fluid,
The same operation as the first or second aspect can be achieved. According to the substrate drying method of the fifth aspect, a vertical plane passing through the centers of the plurality of substrates is used as a reference so that the drying fluid is directed to the vicinity of the center of the substrates through the supply nozzle and corresponding to the gap between the substrates. Since it is supplied obliquely downward and opposite to each other, it is easy to secure a sufficient spread of the drying fluid, and it is possible to achieve the same effect as in claim 1 or claim 2. In the substrate drying method according to the sixth aspect, the vertical direction passing through the centers of the plurality of substrates is directed to direct the drying fluid through the supply nozzle and vertically downward corresponding to the gap between the substrates and near the center of the substrates. In addition to supplying diagonally downwards with respect to each other on the basis of the surface, the vertical initial introduction speed is set to be greater than the diagonal downwards initial introduction speed, so that it is easy to ensure a sufficient spread of the drying fluid, The same operation as the first or second aspect can be achieved.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a substrate drying method according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic perspective view showing a substrate drying apparatus to which one embodiment of the substrate drying method of the present invention is applied.

The substrate drying apparatus has a processing tank 3 for accommodating a plurality of substrates 1 and discharging a cleaning liquid (eg, pure water) 2 for cleaning the substrates 1. And it has the supply nozzle 4 which supplies the fluid for drying (for example, IPA vapor, IPA mist, etc.). of course,
The supply nozzle 4 is arranged above the substrate 1.
The supply nozzle 4 is preferably set so as to supply the drying fluid downward corresponding to the gap between the substrates 1. The direction of the drying fluid supplied from the supply nozzle 4 is set so as to be directed to the central axis of the plurality of substrates 1 and parallel to the substrates 1.
Further, the initial introduction speed of the drying fluid supplied from the supply nozzle 4 is set so that the drying fluid spreads over the entire width of the substrate 1 on the level of the cleaning liquid as indicated by an arrow in FIG. Specifically, the initial introduction speed is set based on the outer diameter of the substrate 1 and the interval between the substrates 1, and is preferably set in consideration of the distance from the supply nozzle 4 to the level of the cleaning liquid 2.

The operation of the substrate drying apparatus having the above configuration is as follows.

After the cleaning liquid 2 is accommodated in the processing tank 3 accommodating the substrate 1 to wash the substrate 1, the drying liquid is supplied through the supply nozzle 4 while discharging the cleaning liquid 2 and lowering the liquid level of the cleaning liquid 2. I do. As a result, the liquid layer 5 of the sprayed drying fluid is formed on the surface of the cleaning liquid 2, so that a portion of the plurality of substrates 1 exposed from the liquid surface of the cleaning liquid 2 is quickly formed by the Marangoni effect. And it can be dried evenly.

When a certain portion of the plurality of substrates 1 is located above the level of the cleaning liquid 2, when the drying fluid is supplied from the supply nozzle 4, the direction and introduction of the drying fluid are controlled. Since the initial velocity is set as described above, the drying fluid smoothly enters the gap between the substrates 1 and spreads over the entire width of the substrate 1 at the level of the cleaning liquid. As a result, even in these parts,
The liquid layer 5 of the drying fluid is formed on the surface of the cleaning liquid 2, so that quick and even drying can be continued by the Marangoni effect.

As is clear from the above description, by setting the direction and the initial introduction speed of the drying fluid, the drying fluid can smoothly enter the gap between the substrates 1. Need not be increased unnecessarily, and the temperature of the drying fluid does not need to be increased. As a result, running costs can be reduced.

FIG. 3 is a schematic vertical sectional view showing another example of the configuration of the supply nozzle 4. As shown in FIG.

The supply nozzle 4 is provided with two sub supply nozzles 4b with a main supply nozzle 4a located at the center therebetween. The supply amount from each nozzle is set such that the flow rate of the drying fluid supplied from the main supply nozzle 4a is sufficiently larger than the flow rate of the drying fluid supplied from the sub supply nozzle 4b. The supply directions of the drying fluid from the nozzles are set in parallel with each other.

When the supply nozzle 4 having this configuration is employed, not only the drying fluid supplied from the main supply nozzle 4a but also the drying fluid supplied from the sub supply nozzle 4b is guided toward the substrate 1. Therefore, it is easy to secure a sufficient spread of the drying fluid, and it is possible to achieve good drying of the substrate 1.

FIG. 4 is a schematic vertical sectional view showing still another example of the configuration of the supply nozzle 4. As shown in FIG.

The supply nozzle 4 is provided with four sub supply nozzles 4b with a main supply nozzle 4a located at the center therebetween. The supply amount from each nozzle is set such that the flow rate of the drying fluid supplied from the main supply nozzle 4a is sufficiently larger than the flow rate of the drying fluid supplied from the sub supply nozzle 4b. The supply directions of the drying fluid from the nozzles are set in parallel with each other.

When the supply nozzle 4 having this configuration is employed, it is easier to ensure a sufficient spread of the drying fluid,
Good drying of the substrate 1 can be achieved.

FIG. 5 is a schematic longitudinal sectional view showing still another example of the configuration of the supply nozzle 4. As shown in FIG.

This supply nozzle 4 is provided with two sub supply nozzles 4b with a main supply nozzle 4a located at the center therebetween. The supply amount from each nozzle is set such that the flow rate of the drying fluid supplied from the main supply nozzle 4a is sufficiently larger than the flow rate of the drying fluid supplied from the sub supply nozzle 4b. The supply direction of the drying fluid from each nozzle is set so as to be near the central axis of the plurality of substrates 1.

When the supply nozzle 4 having this configuration is employed, not only the drying fluid supplied from the main supply nozzle 4a but also the drying fluid supplied from the sub-supply nozzle 4b is supplied to the center of the plurality of substrates 1. While being guided toward the vicinity of the axis, the flow of the drying fluid supplied from the sub-supply nozzle 4b is changed by the flow of the drying fluid supplied from the main supply nozzle 4a. Thus, the substrate 1 can be easily secured, and good drying of the substrate 1 can be achieved.

FIG. 6 is a schematic longitudinal sectional view showing still another example of the configuration of the supply nozzle 4. As shown in FIG.

The supply nozzle 4 is different from the supply nozzle 4 shown in FIG. 5 only in that the main supply nozzle 4a is omitted and the initial speed of the introduction of the drying fluid supplied from the sub supply nozzle 4b is set large.

When the supply nozzle 4 having this configuration is employed, the drying fluid supplied from the sub supply nozzle 4b is guided toward the vicinity of the central axis of the plurality of substrates 1 and supplied from the sub supply nozzle 4b. Since the flow of the drying fluid to be performed is in a synthesized state, it is easy to secure a sufficient spread of the drying fluid, and it is possible to achieve excellent drying of the substrate 1.

[0034]

According to the first aspect of the present invention, the direction of introduction and the initial speed of introduction can be easily set, and the diameter of the substrate is increased and / or the distance between the substrates is reduced. In addition, the drying fluid can be smoothly supplied to the gap between the substrates, and the liquid phase of the drying fluid can be continuously formed on the surface of the cleaning liquid. It is possible to achieve drying, and it is not necessary to increase the concentration of the drying fluid more than necessary, and it is not necessary to increase the temperature of the drying fluid more than necessary. It has a unique effect that it can be performed.

[0035]

According to the second aspect of the present invention, it is possible to set an optimal initial introduction speed in accordance with the relative drop of the level of the cleaning liquid. Claim 3
Can introduce a drying fluid into the gap between the substrates,
The same effect as the first or second aspect is achieved. According to the fourth aspect of the invention, it is easy to secure a sufficient spread of the drying fluid, and the same effect as that of the first or second aspect is obtained. According to the fifth aspect of the invention, it is easy to secure a sufficient spread of the drying fluid, and the same effect as that of the first or second aspect is obtained. According to the invention of claim 6, it is easy to secure a sufficient spread of the drying fluid, and the same effect as that of claim 1 or 2 can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing a substrate drying apparatus to which one embodiment of a substrate drying method of the present invention is applied.

FIG. 2 is a schematic vertical sectional view showing a flow of a drying fluid.

FIG. 3 is a schematic vertical sectional view showing another example of the configuration of the supply nozzle.

FIG. 4 is a schematic perspective view showing still another example of the configuration of the supply nozzle.

FIG. 5 is a schematic perspective view showing still another example of the configuration of the supply nozzle.

FIG. 6 is a schematic perspective view showing still another example of the configuration of the supply nozzle.

[Explanation of symbols]

 1 Substrate 2 Cleaning liquid 3 Processing tank

Continued on the front page (72) Inventor Awaihara Dai 1304, Kanaokacho, Sakai-shi, Osaka Daikin Industries, Ltd.Kanaoka Plant (72) Inventor Masao 1304, Kanaokacho, Sakai-shi, Osaka Daikin Industries, Ltd.Kanaoka Plant (72) Inventor Ki Kanami 1304 Kanaokacho, Sakai City, Osaka Prefecture Daikin Industries, Ltd. Kanaoka Factory (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 21/304 F26B 3/02

Claims (6)

(57) [Claims] A plurality of substrates (1) are accommodated in a processing tank (3), and processing is performed while lowering the level of a cleaning liquid (2) in the processing tank (3) relative to the substrates. Tank (3)
A method of drying the surface of the substrate (1) by supplying a drying fluid therein, wherein the drying fluid spreads over the entire width of the substrate (1) at the level of the cleaning liquid (2). Is set such that the drying fluid is directed toward the center of the substrate, and the initial speed of introduction of the drying fluid is set based on the outer diameter of the substrate (1) and the distance between the substrates. A method for drying a substrate, comprising: 2. The substrate drying method according to claim 1, wherein the initial introduction speed of the drying fluid is set based on a relative position between the substrate (1) and the liquid level of the cleaning liquid (2). 3. The substrate drying method according to claim 1, wherein the drying fluid is supplied downward through a supply nozzle and corresponding to a gap between the substrates. 4. The drying fluid is supplied vertically downward through a supply nozzle and corresponding to a gap between the substrates, and an initial introduction speed corresponding to a central portion of the substrate is set to an initial introduction speed corresponding to a peripheral portion of the substrate. The method for drying a substrate according to claim 1, wherein the value is set to be larger than the value. 5. A diagonal which is opposite to a vertical plane passing through the centers of a plurality of substrates so as to direct the drying fluid through a supply nozzle and near a center of the substrates corresponding to a gap between the substrates. The substrate drying method according to claim 1, wherein the substrate is supplied downward. 6. A method for directing the drying fluids through a supply nozzle and vertically downward corresponding to the gap between the substrates and near the center of the substrates, based on a vertical plane passing through the centers of the plurality of substrates. The substrate drying method according to claim 1 or 2, wherein the substrate is supplied in the opposite obliquely downward direction, and the vertical initial introduction speed is set to be higher than the obliquely downward initial introduction speed.