JP2021145108A - Cleaning liquid circulation supply device - Google Patents

Abstract

To provide a cleaning liquid circulation supply device in which cleaning liquid returned from a use point and newly supplied ultrapure water are sufficiently mixed and the cleaning liquid having a low fine particle content is supplied to the use point.SOLUTION: A cleaning liquid circulation supply device includes a cleaning liquid tank 1, a feed line 3 that sends the cleaning liquid of the cleaning liquid tank 1 to a use point, addition lines 4, 5, and 6 for adding additives to the feed line 3, a return line 10 that sends unused cleaning liquid from the use point to the cleaning liquid tank 1, an ultrapure water supply line 11 that supplies ultrapure water to the return line 10, and a fine particle removal filter 12 provided on the cleaning liquid tank 1 side of a connection portion of the ultrapure water supply line 11 in the return line 10.SELECTED DRAWING: Figure 1

Description

The present invention relates to a cleaning liquid circulation supply device for circulatingly supplying a cleaning liquid to an electronic device manufacturing process such as a semiconductor or a liquid crystal display.

As a cleaning solution used for wafer processing in the electronic industry field, a solution obtained by adding a conductivity-imparting substance, a redox potential control substance, or a gas to ultrapure water is used (for example, Patent Document 1).

In the conventional circulation supply device for cleaning liquid, ultrapure water is introduced into a tank, and the liquid in the tank is sent to a use point by a circulation forward line (feed line), and a conductivity-imparting substance is supplied in the middle of this circulation forward line. And an additive substance such as an oxidation-reduction potential control substance or a gas is added. This additive is added to supply the cleaning solution to the point of use, some of which is used for cleaning. The cleaning liquid not used at the use point is returned to the tank at the circulation return line (return line).

Japanese Unexamined Patent Publication No. 2005-186067

In the conventional circulation supply device for cleaning liquid, the cleaning liquid is continuously sent from the above tank to the use point. Even if the wafer is not cleaned at the point of use, the cleaning liquid is circulated through the circulation forward line and the return line. The cleaning liquid in the tank is a mixture of the return cleaning liquid from the use point and the new ultrapure water supplied to the tank. Therefore, in order to keep the quality of the cleaning liquid sent to the use point constant. It is necessary to appropriately control the mixing ratio of the amount of cleaning liquid returned from the use point and the amount of new ultrapure water, and to mix the two sufficiently.

The present invention provides a circulation supply device for a cleaning liquid in which the cleaning liquid returned from the use point and the newly supplied ultrapure water are sufficiently mixed and the cleaning liquid having a low fine particle content is supplied to the use point. The purpose is to do.

The cleaning liquid circulation supply device of the present invention includes a cleaning liquid tank, a feed line for supplying the cleaning liquid of the cleaning liquid tank to a use point, an additive substance adding means for adding an additive substance to the feed line, and unused from the use point. A return line for supplying cleaning liquid to the cleaning liquid tank, an ultrapure water supply line for supplying ultrapure water to the return line, and the cleaning liquid tank side of the return line with respect to the connection portion of the ultrapure water supply line. It is provided with a fine particle removal filter provided in.

In one aspect of the present invention, the fine particle removing filter is characterized by having an average pore diameter of 50 to 500 nm.

In one aspect of the present invention, the additive substance is at least one of a conductivity-imparting substance, a substance that adjusts the redox potential, a substance that adjusts pH, and a gas.

According to the cleaning liquid circulation supply device of the present invention, ultrapure water is supplied to the return line, so that the cleaning liquid returned from the use point and the ultrapure water supplied to the return line tank in the return line. Mix well while flowing to.

Further, in the cleaning liquid circulation supply device of the present invention, since the fine particle removal filter is arranged on the tank side of the return line from the connection portion of the ultrapure water supply line, the fine particle removal filter is agitated and mixed in the same manner as the line mixer. By acting, the mixing of the return cleaning liquid and the ultrapure water is further promoted.

Further, by providing a fine particle removing filter, fine particles in the cleaning liquid are removed.

It is a flow figure of the circulation supply apparatus of the cleaning liquid which concerns on embodiment. It is a flow chart of the circulation supply device of the cleaning liquid which concerns on a comparative example. It is a flow chart of the circulation supply device of the cleaning liquid which concerns on a comparative example. It is a flow chart of the circulation supply device of the cleaning liquid which concerns on a comparative example.

Hereinafter, embodiments will be described with reference to the drawings. FIG. 1 shows a cleaning liquid circulation supply device according to the first embodiment. In this cleaning liquid circulation supply device, the cleaning liquid in the cleaning liquid tank 1 is sent to the use point via the feed line 3 having the pump 2, and the conductivity-imparting substance, the redox potential control substance, or the gas is added in the middle of the water supply. It is added from lines 4, 5 or 6. Although not shown, a pH adjusting substance may be added. A conductivity meter 7, an ORP meter 8, and a gas concentration meter 9 are installed on the feed line 3.

The unused cleaning liquid surplus at the use point is returned to the cleaning liquid tank 1 via the return line 10. In this embodiment, the ultrapure water supply line 11 is connected in the middle of the return line 10. Further, the fine particle removal filter 12 is installed in the middle of the return line 10 and on the tank 1 side (downstream side) of the connection portion of the ultrapure water supply line 11. As the fine particle removing filter 12, a filter having an average pore diameter of 500 nm or less, for example, 50 to 500 nm is suitable.

Flow meters 13 and 14 are provided in the feed line 3 and the ultrapure water supply line 11.

Examples of the conductivity-imparting substance include ammonia and carbonic acid. Examples of the substance that adjusts the redox potential include hydrogen peroxide and ozone. Examples of the gas include hydrogen, nitrogen, carbon dioxide gas, ozone and the like.

Examples of the substance for adjusting the pH include ammonia, carbonic acid, hydrochloric acid and the like.

In the cleaning liquid circulation supply device configured in this way, the ultrapure water is supplied from the ultrapure water supply line 11 to the return line 10, so that the cleaning liquid returned from the use point and the return line 10 are supplied. Ultrapure water is sufficiently mixed while flowing through the return line 10 to the tank 1. Further, since the fine particle removing filter 12 is arranged on the tank 1 side of the return line 10 with respect to the connecting portion of the ultrapure water supply line 11, the fine particles in the cleaning liquid are removed and the fine particle removing filter 12 is lined up. By performing the same stirring and mixing action as the mixer, the mixing of the return cleaning liquid and the ultrapure water is further promoted.

[Example 1]
In the cleaning liquid circulation supply device shown in FIG. 1, the cleaning liquid is sent from the tank 1 having a capacity of 50 L to the feed line 3 by the pump 2, and ammonia (conductivity-imparting substance) is added so that the conductivity becomes 30 μS / cm. The liquid was sent to the use point at 50 L / min to wash the wafer. The cleaning liquid not used for wafer cleaning was returned to the tank 1 from the return line 10 through the fine particle removing filter 12. The amount of wastewater used in wafer cleaning was supplied from the ultrapure water supply line 11 to the return line 10 to maintain the material balance of the cleaning liquid. As the fine particle removing filter 12, a filter made of polysulfone having an average pore diameter of 100 nm was used.

After continuing the circulation supply of the cleaning liquid for 5 hours, the number of particles in the cleaning liquid was 1 particle / mL (500 nm or more), and the variation in the conductivity of the cleaning liquid sent to the use point was ± 5%. The results are shown in Table 1.

[Example 2]
In Example 1, the experiment was carried out under the same conditions except that hydrogen peroxide was added instead of ammonia so that the redox potential was 600 mV. As a result, as shown in Table 1, the number of particles in the cleaning liquid was 1 particle / mL (500 nm or more), and the variation in the conductivity of the cleaning liquid sent to the use point was ± 5%.

[Example 3]
In Example 1, the experiment was carried out under the same conditions except that hydrogen gas was added so that the hydrogen gas concentration was 1 ppm instead of ammonia. As a result, as shown in Table 1, the number of particles in the cleaning liquid was 1 particle / mL (500 nm or more), and the variation in the conductivity of the cleaning liquid sent to the use point was ± 5%.

[Example 4]
In Example 1, the experiment was carried out under the same conditions except that ammonia was added so that the pH became 9.0. As a result, as shown in Table 1, the number of particles in the cleaning liquid was 1 particle / mL (500 nm or more), and the variation in the conductivity of the cleaning liquid sent to the use point was ± 5%.

[Example 5]
In Example 1, the conditions were the same except that ammonia, hydrogen peroxide, and hydrogen gas were added so that the conductivity was 30 μS / cm, the redox potential was 700 mV, the hydrogen gas concentration was 1 ppm, and the pH was 9.0. The experiment was conducted. As a result, as shown in Table 1, the number of particles in the cleaning liquid was 1 particle / mL (500 nm or more), and the variation in the conductivity of the cleaning liquid sent to the use point was ± 5%.

[Comparative Example 1]
As shown in FIG. 3, a cleaning liquid circulation supply device configured to directly supply ultrapure water from the ultrapure water supply line 11 to the cleaning liquid tank 1 was used. The other configurations of FIG. 3 are the same as those of FIG.

Using the cleaning liquid circulation supply device shown in FIG. 3, the experiment was conducted under the same conditions except that ammonia was added so that the conductivity was 30 μS / cm. As a result, as shown in Table 1, the number of particles in the cleaning liquid was 8 particles / mL (500 nm or more), and the variation in the conductivity of the cleaning liquid sent to the use point was ± 15%.

[Comparative Example 2]
In Comparative Example 1, the experiment was carried out under the same conditions except that hydrogen gas was added so that the redox potential was 600 mV. As a result, as shown in Table 1, the number of particles in the cleaning liquid was 8 particles / mL (500 nm or more), and the variation in the conductivity of the cleaning liquid sent to the use point was ± 15%.

[Comparative Example 3]
In Comparative Example 1, the experiment was carried out under the same conditions except that hydrogen peroxide was added so that the hydrogen gas concentration was 1 ppm. As a result, as shown in Table 1, the number of particles in the cleaning liquid was 8 particles / mL (500 nm or more), and the variation in the conductivity of the cleaning liquid sent to the use point was ± 15%.

[Comparative Example 4]
In Comparative Example 1, the experiment was carried out under the same conditions except that ammonia was added so that the pH became 9.0. As a result, as shown in Table 1, the number of particles in the cleaning liquid was 8 particles / mL (500 nm or more), and the variation in the conductivity of the cleaning liquid sent to the use point was ± 15%.

[Comparative Example 5]
In Comparative Example 1, the conditions were the same except that ammonia, hydrogen peroxide, and hydrogen gas were added so that the conductivity was 30 μS / cm, the redox potential was 600 mV, the hydrogen gas concentration was 1 ppm, and the pH was 9.0. The experiment was conducted. As a result, as shown in Table 1, the number of particles in the cleaning liquid was 8 particles / mL (500 nm or more), and the variation in the conductivity of the cleaning liquid sent to the use point was ± 15%.

[Comparative Example 6]
A cleaning liquid circulation supply device (tank volume is also 50 L, which is the same as that of Example 1) having the same configuration as that of Example 1 (FIG. 1) was used except that the fine particle removing filter 12 shown in FIG. 2 was omitted. The experiment was carried out under the same conditions except that ammonia was added so that the conductivity was 30 μS / cm. As a result, as shown in Table 1, the number of particles in the cleaning liquid was 15 particles / mL (500 nm or more), and the variation in the conductivity of the cleaning liquid sent to the use point was ± 12%.

[Comparative Example 7]
In Comparative Example 6, the experiment was carried out under the same conditions except that hydrogen peroxide was added so that the redox potential was 600 mV. As a result, as shown in Table 1, the number of particles in the cleaning liquid was 15 particles / mL (500 nm or more), and the variation in the conductivity of the cleaning liquid sent to the use point was ± 12%.

[Comparative Example 8]
In Comparative Example 6, the experiment was carried out under the same conditions except that hydrogen was added so that the hydrogen gas concentration was 1 ppm. As a result, as shown in Table 1, the number of particles in the cleaning liquid was 15 particles / mL (500 nm or more), and the variation in the conductivity of the cleaning liquid sent to the use point was ± 12%.

[Comparative Example 9]
In Comparative Example 6, the experiment was carried out under the same conditions except that ammonia was added so that the pH became 9.0. As a result, as shown in Table 1, the number of particles in the cleaning liquid was 15 particles / mL (500 nm or more), and the variation in the conductivity of the cleaning liquid sent to the use point was ± 12%.

[Comparative Example 10]
In Comparative Example 6, the conditions were the same except that ammonia, hydrogen peroxide, and hydrogen gas were added so that the conductivity was 30 μS / cm, the redox potential was 600 mV, the hydrogen gas concentration was 1 ppm, and the pH was 9.0. The experiment was conducted. As a result, as shown in Table 1, the number of particles in the cleaning liquid was 15 particles / mL (500 nm or more), and the variation in the conductivity of the cleaning liquid sent to the use point was ± 12%.

[Comparative Example 11]
As shown in FIG. 4, a cleaning liquid circulation supply device configured to directly supply ultrapure water from the ultrapure water supply line 11 to the cleaning liquid tank 1 was used. The other configurations of FIG. 4 are the same as those of FIG. However, in FIG. 4, a tank 1 having a volume of 150 L was used.

Using the cleaning liquid circulation supply device shown in FIG. 4, ammonia, hydrogen peroxide, and hydrogen gas were added so that the conductivity was 30 μS / cm, the redox potential was 600 mV, the hydrogen gas concentration was 1 ppm, and the pH was 9.0. The experiment was carried out under the same conditions except that it was added. As a result, as shown in Table 1, the number of particles in the cleaning liquid was 8 particles / mL (500 nm or more), and the variation in the conductivity of the cleaning liquid sent to the use point was ± 8%.

As is clear from the above Examples and Comparative Examples, according to Examples 1 to 5, a cleaning liquid having a small variation in conductivity and a small number of fine particles is supplied to the use point.

In Comparative Examples 1 to 5, since the fine particle removing filter was provided, the number of fine particles in the cleaning liquid was small, but the conductivity varied widely. In Comparative Examples 6 to 11, the variation in conductivity is slightly small, but the number of fine particles is large. Comparative Example 11 has better variations in conductivity and the number of fine particles than Comparative Examples 6 to 10, but is inferior to Examples 1 to 5. In addition, a tank with a large capacity is required.

1 Tank 3 Feed line 10 Return line 11 Ultrapure water supply line 12 Fine particle removal filter

Claims (3)

Cleaning liquid tank and
A feed line that feeds the cleaning liquid from the cleaning liquid tank to the point of use, and
Additive addition means for adding an additive to the feed line, and
A return line that sends unused cleaning liquid from the use point to the cleaning liquid tank, and
An ultrapure water supply line that supplies ultrapure water to the return line,
A cleaning liquid circulation supply device including a fine particle removing filter provided on the cleaning liquid tank side of the return line from the connection portion of the ultrapure water supply line. The cleaning liquid circulation supply device according to claim 1, wherein the fine particle removing filter has an average pore diameter of 50 to 500 nm. The cleaning liquid circulation supply device according to claim 1 or 2, wherein the additive substance is at least one of a conductivity-imparting substance, a substance for adjusting an oxidation-reduction potential, a substance for adjusting pH, and a gas.

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