FUNCTIONAL AQUEOUS SOLUTION SUPPLY APPARATUS

Abstract

Functional aqueous solution supply apparatus (1) has a replenishment water production unit (3) that is supplied with ultrapure water (W) from a pipe conduit (2) and produces functional aqueous solution as washing water (W1), a storage tank (5) that is supplied/replenished with the produced washing water (W1) via a pipe (4), and a circulation pipe conduit (7) that supplies the washing water (W1) from the storage tank (5) to single-wafer type washers (6A, 6B, 6C, and 6D) and returns unused washing water (W1) to the storage tank (5). The circulation pipe conduit (7) is branched into supply pipes (7A, 7B, 7C, and 7D) and is further connected to return pipes (8A, 8B, 8C, and 8D) that communicate into the circulation pipe conduit (7) from the washers (6A, 6B, . . . ), respectively. The operation plan of the washers (6A, 6B, . . . ) is preliminarily transmitted to a control means (9), and this control means (9) can control the replenishment water production unit (3). Such a functional aqueous solution supply apparatus can supply the functional aqueous solution as the washing water to use points such as washing apparatuses for electronic components/electronic members, etc.

Claims

1: A functional aqueous solution supply apparatus comprising: a replenishment water production unit configured to produce washing water which comprises water and one or more functional components selected from a conductivity-imparting substance, a redox potential-adjusting substance, and a pH-adjusting substance; a storage tank configured to store the washing water which is supplied/replenished from the replenishment water production unit; a circulation-type washing water supply pipe configured to supply the washing water from the storage tank to a use point; a return pipe configured to return unused washing water at the use point to the circulation-type washing water supply pipe; and a controller configured to control, based on usage plan information of the washing liquid at the use point, a replenishment amount of the washing water supplied from the replenishment water production unit to the storage tank.

2: The functional aqueous solution supply apparatus according to claim 1, wherein the use point has a plurality of washers.

3: The functional aqueous solution supply apparatus according to claim 1, wherein the conductivity-imparting substance comprises at least one selected from the group consisting of ammonia and carbonic acid.

4: The functional aqueous solution supply apparatus according to claim 1, wherein the redox potential-adjusting substance comprises at least one selected from the group consisting of hydrogen peroxide, O.sub.3, and H.sub.2.

5: The functional aqueous solution supply apparatus according to claim 2, wherein the conductivity-imparting substance comprises at least one selected from the group consisting of ammonia and carbonic acid.

6: The functional aqueous solution supply apparatus according to claim 2, wherein the redox potential-adjusting substance comprises at least one selected from the group consisting of hydrogen peroxide, O.sub.3, and H.sub.2.

7: The functional aqueous solution supply apparatus according to claim 5, wherein the redox potential-adjusting substance comprises at least one selected from the group consisting of hydrogen peroxide, O.sub.3, and H.sub.2.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0015] FIG. 1 is a schematic diagram illustrating the functional aqueous solution supply apparatus according to an embodiment of the present invention.

[0016] FIG. 2 is a schematic diagram illustrating a conventional functional aqueous solution supply apparatus.

EMBODIMENTS FOR CARRYING OUT THE INVENTION

[0017] Hereinafter, an embodiment of the functional aqueous solution supply apparatus of the present invention will be described in detail with reference to the accompanying drawings.

<<Functional Aqueous Solution Supply Apparatus>>

[0018] FIG. 1 illustrates the functional aqueous solution supply apparatus according to an embodiment of the present invention. Specifically, FIG. 1 illustrates a functional aqueous solution supply apparatus 1 for adding a pH-adjusting substance, a redox potential-adjusting substance, etc. to ultrapure water W as the raw material water to produce washing water W1 and supplying the washing water W1 to a washer for semiconductor wafers as a use point. The functional aqueous solution supply apparatus 1 has a replenishment water production unit 3 that is supplied with the ultrapure water W from a pipe conduit 2 and produces functional aqueous solution as the washing water W1, a storage tank 5 that is supplied/replenished with the produced washing water W1 via a pipe 4, and a circulation pipe conduit 7 that supplies the washing water W1 from the storage tank 5 to a plurality of single-wafer type washers 6A, 6B, 6C, and 6D (four washers in the present embodiment) as use points and returns unused washing water W1 to the storage tank 5. The circulation pipe conduit 7 is branched into supply pipes 7A, 7B, 7C, and 7D that supply the washing water W1 to respective washers 6A, 6B, . . . and is further connected to return pipes 8A, 8B, 8C, and 8D that communicate into the circulation pipe conduit 7 from the washers 6A, 6B, . . . , respectively. The operation plan of the washers 6A, 6B, . . . as the use points is preliminarily transmitted to a control means 9 such as a personal computer, and this control means 9 can control the replenishment water production unit 3. Reference numeral 10 represents a drain pipe that discharges drain water DW.

<Ultrapure Water>

[0019] In the present embodiment, preferred properties of the ultrapure water W as the raw water may be, for example, resistivity: 18.1 M?.Math.cm or more, fine particles: 1000 particles/L or less with a particle diameter of 50 nm or more, viable bacteria: 1 bacterium/L or less, TOC (Total Organic Carbon): 1 ?g/L or less, total silicon: 0.1 ?g/L or less, metals: 1 ng/L or less, ions: 10 ng/L or less, hydrogen peroxide; 30 ?g/L or less, and water temperature: 25?2? C.

<pH-Adjusting Substance>

[0020] In the present embodiment, the pH-adjusting substance is not particularly limited, and when adjusting the pH to lower than 7, a liquid such as citric acid, formic acid, or hydrochloric acid or a gas such as CO.sub.2 can be used. When adjusting the pH to 7 or higher, ammonia, sodium hydroxide, potassium hydroxide, or the like can be used. These pH-adjusting substances may also serve as conductivity-imparting substances even when added in very small amounts.

<Redox Potential-Adjusting Substance>

[0021] In the present embodiment, the redox potential-adjusting substance is not particularly limited, but in order to adjust the redox potential to the positive side, a liquid such as hydrogen peroxide water or a gas such as ozone gas (O.sub.3) or oxygen gas (O.sub.2) can be used. On the other hand, in order to adjust the redox potential to the negative side, a liquid such as oxalic acid or a gas such as hydrogen (H.sub.2) can be used.

<<Method of Supplying Functional Water>>

[0022] The description will now be made below for a method of supplying the functional aqueous solution W1 using the functional aqueous solution supply apparatus 1 of the present embodiment having the configuration as described previously.

[0023] First, the washing water (functional aqueous solution) W1 is produced in the replenishment water production unit 3 through supplying the ultrapure water W to the replenishment water production unit 3 and adding one or more selected from a conductivity-imparting substance, a redox potential-adjusting substance, and a pH-adjusting substance. This functional aqueous solution W1 is once stored in the storage tank 5 from the pipe 4. Once a predetermined amount of the washing water W1 is stored, a liquid feed pump (not illustrated) is driven to supply the washing water W1 to the washers 6A, 6B, . . . from the circulation pipe conduit 7 through the supply pipes 7A, 7B, 7C, and 7D. In this operation, the washing water W1 not used in the single-wafer type washers 6A, 6B, 6C, and 6D is returned from the return pipes 8A, 8B, 8C, and 8D to the circulation pipe conduit 7 to flow back into the storage tank 5. The washing water W1 returned at this time is in a state in which the dissolved oxygen is increased due to contact with the air, such as in the single-wafer type washers 6A, 6B, 6C, 6D, etc., so the washing water W1 may be returned after removing the dissolved oxygen as necessary.

[0024] As the washing water W1 is supplied to such single-wafer type washers 6A, 6B, . . . , the washing water W1 in the storage tank 5 decreases. Accordingly, the washing water W1 produced in the replenishment water production unit 3 is replenished to the storage tank 5 through the pipe 4. In the present embodiment, the operating information of the washers 6A, 6B, . . . is preliminarily obtained, and the amount of washing water W1 used is predicted by the control means 9 based on the operating information. Then, the amount of washing water W1 to be produced in the replenishment water production unit 3 is set in accordance with the predicted amount used, and the storage tank 5 is thereby replenished with the washing water W1 in response to the variation in the amount used. This can reduce the production amount of the washing water W1 and also significantly reduce the discharge amount of the washing water W1. Moreover, an additional effect can be obtained that the chemical concentration of the washing water W1 can be controlled with high accuracy.

[0025] The present invention has been described above based on the aforementioned embodiment with reference to the accompanying drawings, but the present invention is not limited to the above embodiment, and various modifications are possible. For example, in the replenishment water production unit 3, pluralities of pH-adjusting substances, redox potential-adjusting substances, etc. can be combined and dissolved to form the functional aqueous solution (washing water) W1.

EXAMPLES

[0026] The present invention will be described in more detail with the following specific examples.

Comparative Example 1

[0027] A simplified version of the functional aqueous solution supply apparatus 1 illustrated in FIG. 1 was prepared as illustrated in FIG. 2. The functional aqueous solution supply apparatus 1 illustrated in FIG. 2 does not have the control means 9 for controlling the replenishment water production unit 3 and is configured to discharge the surplus washing water W1 from the drain pipe 10. Using this functional aqueous solution supply apparatus 1, the ultrapure water W was supplied to the replenishment water production unit 3 at 150 L/min, ammonia (conductivity-imparting substance) was added to the ultrapure water W so that the conductivity would be 1 ?S/cm, hydrogen peroxide (redox potential-adjusting substance) was further added to 100 ppm to produce the washing water (functional aqueous solution) W1, and the produced washing water W1 was sent to the storage tank 5. The washing water W1 was sent from the storage tank 5 to the four washers 6A, 6B, 6C, and 6D, and the unused washing water W1 was returned to the storage tank 5. When the level of the storage tank 5 was low, it was replenished with the washing water W1 from the replenishment water production unit 3, while when the level was high, the washing water W1 produced in the replenishment water production unit 3 was not fed into the storage tank 5 and was discharged from the drain pipe 10 as the drain water DW.

[0028] As a result, the average flow rate of drain water was 110 mL/min. The variation in the ammonia concentration of the washing water W1 sent from the storage tank 5 to the washers 6A, 6B, . . . was <?10%, while the variation in the hydrogen peroxide concentration was also <?10%.

[0029] Table 1 lists the presence or absence of control of the replenishment water production unit, the conductivity-imparting substance and its set value, and the redox potential-adjusting substance and its set concentration in Comparative Example 1. Table 2 lists the variation rate of the conductivity, the variation rate of the concentration of the redox potential-adjusting substance, and the average drain water flow rate.

Comparative Example 2

[0030] Using the functional aqueous solution supply apparatus 1 illustrated in FIG. 2, the ultrapure water W was supplied to the replenishment water production unit 3 at 150 L/min, ammonia was added to the ultrapure water W so that the conductivity would be 100 ?S/cm, hydrogen peroxide was further added to 100 ppm to produce the washing water W1, and the produced washing water W1 was sent to the storage tank 5. The washing water W1 was sent from the storage tank 5 to the four washers 6A, 6B, 6C, and 6D, and the unused washing water W1 was returned to the storage tank 5. When the level of the storage tank 5 was low, it was replenished with the washing water W1 from the replenishment water production unit 3, while when the level was high, the washing water W1 produced in the replenishment water production unit 3 was not fed into the storage tank 5 and was discharged from the drain pipe 10 as the drain water DW.

[0031] As a result, the average flow rate of drain water was 110 L/min. The variation in the ammonia concentration of the washing water W1 sent from the storage tank 5 to the washers 6A, 6B, . . . was <?10%, while the variation in the hydrogen peroxide concentration was also <?10%.

[0032] Table 1 also lists the presence or absence of control of the replenishment water production unit, the conductivity-imparting substance and its set value, and the redox potential-adjusting substance and its set concentration in Comparative Example 2. Table 2 also lists the variation rate of the conductivity, the variation rate of the concentration of the redox potential-adjusting substance, and the average drain water flow rate.

Comparative Example 3

[0033] Using the functional aqueous solution supply apparatus 1 illustrated in FIG. 2, the ultrapure water W was supplied to the replenishment water production unit 3 at 150 L/min, ammonia was added to the ultrapure water W so that the conductivity would be 100 ?S/cm, ozone (O.sub.3) (redox potential-adjusting substance) was further added to 30 ppm to produce the washing water W1, and the produced washing water W1 was sent to the storage tank 5. The washing water W1 was sent from the storage tank 5 to the four washers 6A, 6B, 6C, and 6D, and the unused washing water W1 was returned to the storage tank 5. When the level of the storage tank 5 was low, it was replenished with the washing water W1 from the replenishment water production unit 3, while when the level was high, the washing water W1 produced in the replenishment water production unit 3 was not fed into the storage tank 5 and was discharged from the drain pipe 10 as the drain water DW.

[0034] As a result, the average flow rate of drain water was 110 L/min. The variation in the ammonia concentration of the washing water W1 sent from the storage tank 5 to the washers 6A, 6B, . . . was <?10%, while the variation in the ozone concentration was also <?10%.

[0035] Table 1 also lists the presence or absence of control of the replenishment water production unit, the conductivity-imparting substance and its set value, and the redox potential-adjusting substance and its set concentration in Comparative Example 3. Table 2 also lists the variation rate of the conductivity, the variation rate of the concentration of the redox potential-adjusting substance, and the average drain water flow rate.

Comparative Example 4

[0036] Using the functional aqueous solution supply apparatus 1 illustrated in FIG. 2, the ultrapure water W was supplied to the replenishment water production unit 3 at 150 L/min, ammonia was added to the ultrapure water W so that the conductivity would be 100 ?S/cm, hydrogen gas (H.sub.2) (redox potential-adjusting substance) was further added to 1.2 ppm to produce the washing water W1, and the produced washing water W1 was sent to the storage tank 5. The washing water W1 was sent from the storage tank 5 to the four washers 6A, 6B, 6C, and 6D, and the unused washing water W1 was returned to the storage tank 5. When the level of the storage tank was low, it was replenished with the washing water W1 from the replenishment water production unit 3, while when the level was high, the washing water W1 produced in the replenishment water production unit 3 was not fed into the storage tank 5 and was discharged from the drain pipe 10 as the drain water DW.

[0037] As a result, the average flow rate of drain water was 110 L/min. The variation in the ammonia concentration of the washing water W1 sent from the storage tank 5 to the washers 6A, 6B, . . . was <?10%, while the variation in the hydrogen concentration was also <?10%.

[0038] Table 1 also lists the presence or absence of control of the replenishment water production unit, the conductivity-imparting substance and its set value, and the redox potential-adjusting substance and its set concentration in Comparative Example 4. Table 2 also lists the variation rate of the conductivity, the variation rate of the concentration of the redox potential-adjusting substance, and the average drain water flow rate.

Comparative Example 5

[0039] Using the functional aqueous solution supply apparatus 1 illustrated in FIG. 2, the ultrapure water W was supplied to the replenishment water production unit 3 at 150 L/min, carbon dioxide (002) (conductivity-imparting substance) was added to the ultrapure water W so that the conductivity would be 10 ?S/cm, hydrogen peroxide was further added to 100 ppm to produce the washing water W1, and the produced washing water W1 was sent to the storage tank 5. The washing water W1 was sent from the storage tank 5 to the four washers 6A, 6B, 6C, and 6D, and the unused washing water W1 was returned to the storage tank 5. When the level of the storage tank was low, it was replenished with the washing water W1 from the replenishment water production unit 3, while when the level was high, the washing water W1 produced in the replenishment water production unit 3 was not fed into the storage tank 5 and was discharged from the drain pipe 10 as the drain water DW.

[0040] As a result, the average flow rate of drain water was 110 L/min. The variation in the carbonic acid concentration of the washing water W1 sent from the storage tank 5 to the washers 6A, 6B, . . . was <?10%, while the variation in the hydrogen peroxide concentration was also <?10%.

[0041] Table 1 also lists the presence or absence of control of the replenishment water production unit, the conductivity-imparting substance and its set value, and the redox potential-adjusting substance and its set concentration in Comparative Example 5. Table 2 also lists the variation rate of the conductivity, the variation rate of the concentration of the redox potential-adjusting substance, and the average drain water flow rate.

Comparative Example 6

[0042] Using the functional aqueous solution supply apparatus 1 illustrated in FIG. 2, the ultrapure water W was supplied to the replenishment water production unit 3 at 150 L/min, carbon dioxide (CO.sub.2) was added to the ultrapure water W so that the conductivity would be 10 ?S/cm, ozone (O.sub.3) was further added to 30 ppm to produce the washing water W1, and the produced washing water W1 was sent to the storage tank 5. The washing water W1 was sent from the storage tank 5 to the four washers 6A, 6B, 6C, and 6D, and the unused washing water W1 was returned to the storage tank 5. When the level of the storage tank 5 was low, it was replenished with the washing water W1 from the replenishment water production unit 3, while when the level was high, the washing water W1 produced in the replenishment water production unit 3 was not fed into the storage tank 5 and was discharged from the drain pipe 10 as the drain water DW.

[0043] As a result, the average flow rate of drain water was 110 L/min. The variation in the carbonic acid concentration of the washing water W1 sent from the storage tank 5 to the washers 6A, 6B, . . . was <?10%, while the variation in the ozone concentration was also <?10%.

[0044] Table 1 also lists the presence or absence of control of the replenishment water production unit, the conductivity-imparting substance and its set value, and the redox potential-adjusting substance and its set concentration in Comparative Example 6. Table 2 also lists the variation rate of the conductivity, the variation rate of the concentration of the redox potential-adjusting substance, and the average drain water flow rate.

Comparative Example 7

[0045] Using the functional aqueous solution supply apparatus 1 illustrated in FIG. 2, the ultrapure water W was supplied to the replenishment water production unit 3 at 150 L/min, carbon dioxide (CO.sub.2) was added to the ultrapure water W so that the conductivity would be 10 ?S/cm, hydrogen gas (H.sub.2) was further added to 1.2 ppm to produce the washing water W1, and the produced washing water W1 was sent to the storage tank 5. The washing water W1 was sent from the storage tank 5 to the four washers 6A, 6B, 6C, and 6D, and the unused washing water W1 was returned to the storage tank 5. When the level of the storage tank 5 was low, it was replenished with the washing water W1 from the replenishment water production unit 3, while when the level was high, the washing water W1 produced in the replenishment water production unit 3 was not fed into the storage tank 5 and was discharged from the drain pipe 10 as the drain water DW.

[0046] As a result, the average flow rate of drain water was 110 L/min. The variation in the carbonic acid concentration of the washing water W1 sent from the storage tank 5 to the washers 6A, 6B, . . . was <?10%, while the variation in the hydrogen concentration was also <?10%.

[0047] Table 1 also lists the presence or absence of control of the replenishment water production unit, the conductivity-imparting substance and its set value, and the redox potential-adjusting substance and its set concentration in Comparative Example 6. Table 2 also lists the variation rate of the conductivity, the variation rate of the concentration of the redox potential-adjusting substance, and the average drain water flow rate.

Comparative Example 8

[0048] Using the functional aqueous solution supply apparatus 1 illustrated in FIG. 2, the ultrapure water W was supplied to the replenishment water production unit 3 at 150 L/min, ammonia was added to the ultrapure water W so that the conductivity would be 1 ?S/cm, hydrogen peroxide was further added to 100 ppm to produce the washing water W1, and the produced washing water W1 was sent to the storage tank 5. The washing water W1 was sent from the storage tank 5 to the four washers 6A, 6B, 6C, and 6D, and the unused washing water W1 was returned to the storage tank 5. When the level of the storage tank 5 was low, it was replenished with the washing water W1 from the replenishment water production unit 3, while when the level was high, the production of the washing water W1 in the replenishment water production unit 3 was stopped.

[0049] As a result, the average flow rate of drain water was 0 L/min. The variation in the ammonia concentration of the washing water W1 sent from the storage tank 5 to the washers 6A, 6B, . . . was <?200%, while the variation in the hydrogen peroxide concentration was <?100%. From these facts, it has been found that the amount of drain water is small, but the variations in the concentrations are large and not practical.

[0050] Table 1 also lists the presence or absence of control of the replenishment water production unit, the conductivity-imparting substance and its set value, and the redox potential-adjusting substance and its set concentration in Comparative Example 8. Table 2 also lists the variation rate of the conductivity, the variation rate of the concentration of the redox potential-adjusting substance, and the average drain water flow rate.

Comparative Example 9

[0051] Using the functional aqueous solution supply apparatus 1 illustrated in FIG. 2, the ultrapure water W was supplied to the replenishment water production unit 3 at 150 L/min, ammonia was added to the ultrapure water W so that the conductivity would be 100 ?S/cm, hydrogen peroxide was further added to 100 ppm to produce the washing water (functional aqueous solution) W1, and the produced washing water W1 was sent to the storage tank 5. The washing water W1 was sent from the storage tank 5 to the four washers 6A, 6B, 6C, and 6D, and the unused washing water W1 was returned to the storage tank 5. When the level of the storage tank was low, it was replenished with the washing water W1 from the replenishment water production unit 3, while when the level was high, the production of the washing water W1 in the replenishment water production unit 3 was stopped.

[0052] As a result, the average flow rate of drain water was 0 L/min. The variation in the ammonia concentration of the washing water W1 sent from the storage tank 5 to the washers 6A, 6B, . . . was <?80%, while the variation in the hydrogen peroxide concentration was <?100%. From these facts, it has been found that the amount of drain water is small, but the variations in the concentrations are large and not practical.

[0053] Table 1 also lists the presence or absence of control of the replenishment water production unit, the conductivity-imparting substance and its set value, and the redox potential-adjusting substance and its set concentration in Comparative Example 9. Table 2 also lists the variation rate of the conductivity, the variation rate of the concentration of the redox potential-adjusting substance, and the average drain water flow rate.

Example 1

[0054] Using the functional aqueous solution supply apparatus 1 illustrated in FIG. 1, the ultrapure water W was supplied to the replenishment water production unit 3, ammonia (conductivity-imparting substance) was added to the ultrapure water W so that the conductivity would be 1 ?S/cm, hydrogen peroxide (redox potential-adjusting substance) was further added to 100 ppm to produce the washing water (functional aqueous solution) W1, and the produced washing water W1 was sent to the storage tank 5. The washing water W1 was sent from the storage tank 5 to the four washers 6A, 6B, 6C, and 6D, and the unused washing water W1 was returned to the storage tank 5. Then, data on the amount of washing water W1 used was preliminarily calculated by the control means 9 from the operating information of the washers 6A, 6B, 6C, and 6D, the replenishment water production unit 3 was controlled based on the data on the amount of washing water W1 used, and the production amount of the washing water W1 in the replenishment water production unit 3 was adjusted in accordance with that amount used. In this operation, surplus washing water W1 was discharged as drain water.

[0055] As a result, the average flow rate of drain water was 30 mL/min. The variation in the ammonia concentration of the washing water W1 sent from the storage tank 5 to the washers 6A, 6B, . . . was <?10%, while the variation in the hydrogen peroxide concentration was also <?10%.

[0056] Table 1 also lists the presence or absence of control of the replenishment water production unit, the conductivity-imparting substance and its set value, and the redox potential-adjusting substance and its set concentration in Example 1. Table 2 also lists the variation rate of the conductivity, the variation rate of the concentration of the redox potential-adjusting substance, and the average drain water flow rate.

Example 2

[0057] Using the functional aqueous solution supply apparatus 1 illustrated in FIG. 1, the ultrapure water W was supplied to the replenishment water production unit 3, ammonia was added to the ultrapure water W so that the conductivity would be 100 ?S/cm, hydrogen peroxide was further added to 100 ppm to produce the washing water W1, and the produced washing water W1 was sent to the storage tank 5. The washing water W1 was sent from the storage tank 5 to the four washers 6A, 6B, 6C, and 6D, and the unused washing water W1 was returned to the storage tank 5. Then, data on the amount of washing water W1 used was preliminarily calculated by the control means 9 from the operating information of the washers 6A, 6B, 6C, and 6D, the replenishment water production unit 3 was controlled based on the data on the amount of washing water W1 used, and the production amount of the washing water W1 in the replenishment water production unit 3 was adjusted in accordance with that amount used. In this operation, surplus washing water W1 was discharged as drain water.

[0058] As a result, the average flow rate of drain water was 30 mL/min. The variation in the ammonia concentration of the washing water W1 sent from the storage tank 5 to the washers 6A, 6B, . . . was <?10%, while the variation in the hydrogen peroxide concentration was also <?10%.

[0059] Table 1 also lists the presence or absence of control of the replenishment water production unit, the conductivity-imparting substance and its set value, and the redox potential-adjusting substance and its set concentration in Example 2. Table 2 also lists the variation rate of the conductivity, the variation rate of the concentration of the redox potential-adjusting substance, and the average drain water flow rate.

Example 3

[0060] Using the functional aqueous solution supply apparatus 1 illustrated in FIG. 1, the ultrapure water W was supplied to the replenishment water production unit 3, ammonia was added to the ultrapure water W so that the conductivity would be 100 ?S/cm, ozone (O.sub.3) (redox potential-adjusting substance) was further added to 30 ppm to produce the washing water W1, and the produced washing water W1 was sent to the storage tank 5. The washing water W1 was sent from the storage tank 5 to the four washers 6A, 6B, 6C, and 6D, and the unused washing water W1 was returned to the storage tank 5. Then, data on the amount of washing water W1 used was preliminarily calculated by the control means 9 from the operating information of the washers 6A, 6B, 6C, and 6D, the replenishment water production unit 3 was controlled based on the data on the amount of washing water W1 used, and the production amount of the washing water W1 in the replenishment water production unit 3 was adjusted in accordance with that amount used. In this operation, surplus washing water W1 was discharged as drain water.

[0061] As a result, the average flow rate of drain water was 30 mL/min. The variation in the ozone concentration of the washing water W1 sent from the storage tank 5 to the washers 6A, 6B, . . . was <?10%, while the variation in the hydrogen peroxide concentration was also <?10%.

[0062] Table 1 also lists the presence or absence of control of the replenishment water production unit, the conductivity-imparting substance and its set value, and the redox potential-adjusting substance and its set concentration in Example 3. Table 2 also lists the variation rate of the conductivity, the variation rate of the concentration of the redox potential-adjusting substance, and the average drain water flow rate.

Example 4

[0063] Using the functional aqueous solution supply apparatus 1 illustrated in FIG. 1, the ultrapure water W was supplied to the replenishment water production unit 3, ammonia was added to the ultrapure water W so that the conductivity would be 100 ?S/cm, hydrogen gas (H.sub.2) (redox potential-adjusting substance) was further added to 1.2 ppm to produce the washing water W1, and the produced washing water W1 was sent to the storage tank 5. The washing water W1 was sent from the storage tank 5 to the four washers 6A, 6B, 6C, and 6D, and the unused washing water W1 was returned to the storage tank 5. Then, data on the amount of washing water W1 used was preliminarily calculated by the control means 9 from the operating information of the washers 6A, 6B, 6C, and 6D, the replenishment water production unit 3 was controlled based on the data on the amount of washing water W1 used, and the production amount of the washing water W1 in the replenishment water production unit 3 was adjusted in accordance with that amount used. In this operation, surplus washing water W1 was discharged as drain water.

[0064] As a result, the average flow rate of drain water was 30 mL/min. The variation in the ammonia concentration of the washing water W1 sent from the storage tank 5 to the washers 6A, 6B, . . . was <?10%, while the variation in the hydrogen concentration was also <?10%.

[0065] Table 1 also lists the presence or absence of control of the replenishment water production unit, the conductivity-imparting substance and its set value, and the redox potential-adjusting substance and its set concentration in Example 4. Table 2 also lists the variation rate of the conductivity, the variation rate of the concentration of the redox potential-adjusting substance, and the average drain water flow rate.

Example 5

[0066] Using the functional aqueous solution supply apparatus 1 illustrated in FIG. 1, the ultrapure water W was supplied to the replenishment water production unit 3, carbon dioxide (CO.sub.2) (conductivity-imparting substance) was added to the ultrapure water W so that the conductivity would be 10 ?S/cm, hydrogen peroxide was further added to 100 ppm to produce the washing water W1, and the produced washing water W1 was sent to the storage tank 5. The washing water W1 was sent from the storage tank 5 to the four washers 6A, 6B, 6C, and 6D, and the unused washing water W1 was returned to the storage tank 5. Then, data on the amount of washing water W1 used was preliminarily calculated by the control means 9 from the operating information of the washers 6A, 6B, 6C, and 6D, the replenishment water production unit 3 was controlled based on the data on the amount of washing water W1 used, and the production amount of the washing water W1 in the replenishment water production unit 3 was adjusted in accordance with that amount used. In this operation, surplus washing water W1 was discharged as drain water.

[0067] As a result, the average flow rate of drain water was 30 mL/min. The variation in the carbonic acid concentration of the washing water W1 sent from the storage tank 5 to the washers 6A, 6B, . . . was <?10%, while the variation in the hydrogen peroxide concentration was also <?10%.

[0068] Table 1 also lists the presence or absence of control of the replenishment water production unit, the conductivity-imparting substance and its set value, and the redox potential-adjusting substance and its set concentration in Example 5. Table 2 also lists the variation rate of the conductivity, the variation rate of the concentration of the redox potential-adjusting substance, and the average drain water flow rate.

Example 6

[0069] Using the functional aqueous solution supply apparatus 1 illustrated in FIG. 1, the ultrapure water W was supplied to the replenishment water production unit 3, carbon dioxide (CO.sub.2) was added to the ultrapure water W so that the conductivity would be 10 ?S/cm, ozone (O.sub.3) was further added to 30 ppm to produce the washing water W1, and the produced washing water W1 was sent to the storage tank 5. The washing water W1 was sent from the storage tank 5 to the four washers 6A, 6B, 6C, and 6D, and the unused washing water W1 was returned to the storage tank 5. Then, data on the amount of washing water W1 used was preliminarily calculated by the control means 9 from the operating information of the washers 6A, 6B, 6C, and 6D, the replenishment water production unit 3 was controlled based on the data on the amount of washing water W1 used, and the production amount of the washing water W1 in the replenishment water production unit 3 was adjusted in accordance with that amount used. In this operation, surplus washing water W1 was discharged as drain water.

[0070] As a result, the average flow rate of drain water was 30 mL/min. The variation in the carbonic acid concentration of the washing water W1 sent from the storage tank 5 to the washers 6A, 6B, . . . was <?10%, while the variation in the ozone concentration was also <?10%.

[0071] Table 1 also lists the presence or absence of control of the replenishment water production unit, the conductivity-imparting substance and its set value, and the redox potential-adjusting substance and its set concentration in Example 6. Table 2 also lists the variation rate of the conductivity, the variation rate of the concentration of the redox potential-adjusting substance, and the average drain water flow rate.

Example 7

[0072] Using the functional aqueous solution supply apparatus 1 illustrated in FIG. 1, the ultrapure water W was supplied to the replenishment water production unit 3, carbon dioxide (CO.sub.2) was added to the ultrapure water W so that the conductivity would be 10 ?S/cm, hydrogen gas (H.sub.2) was further added to 1.2 ppm to produce the washing water (functional aqueous solution) W1, and the produced washing water W1 was sent to the storage tank 5. The washing water W1 was sent from the storage tank 5 to the four washers 6A, 6B, 6C, and 6D, and the unused washing water W1 was returned to the storage tank 5. Then, data on the amount of washing water W1 used was preliminarily calculated by the control means 9 from the operating information of the washers 6A, 6B, 6C, and 6D, the replenishment water production unit 3 was controlled based on the data on the amount of washing water W1 used, and the production amount of the washing water W1 in the replenishment water production unit 3 was adjusted in accordance with that amount used. In this operation, surplus washing water W1 was discharged as drain water.

[0073] As a result, the average flow rate of drain water was 30 mL/min. The variation in the carbonic acid concentration of the washing water W1 sent from the storage tank 5 to the washers 6A, 6B, . . . was <?10%, while the variation in the hydrogen concentration was also <?10%.

[0074] Table 1 also lists the presence or absence of control of the replenishment water production unit, the conductivity-imparting substance and its set value, and the redox potential-adjusting substance and its set concentration in Example 7. Table 2 also lists the variation rate of the conductivity, the variation rate of the concentration of the redox potential-adjusting substance, and the average drain water flow rate.

TABLE-US-00001 TABLE 1 Redox potential- Conductivity- Redox adjusting Presence Conductivity- imparting potential- substance or absence imparting substance set adjusting concentration Example No. of control substance value (?S/cm) substance (ppm) Comparative Absent Ammonia 1 Hydrogen 100 Example 1 peroxide Comparative Absent Ammonia 100 Hydrogen 100 Example 2 peroxide Comparative Absent Ammonia 100 O.sub.3 30 Example 3 Comparative Absent Ammonia 100 H.sub.2 1.2 Example 4 Comparative Absent CO.sub.2 10 Hydrogen 100 Example 5 peroxide Comparative Absent CO.sub.2 10 O.sub.3 30 Example 6 Comparative Absent CO.sub.2 10 H.sub.2 1.2 Example 7 Comparative Absent Ammonia 1 Hydrogen 100 Example 8 peroxide Comparative Absent Ammonia 100 Hydrogen 100 Example 9 peroxide Example 1 Present Ammonia 1 Hydrogen 100 peroxide Example 2 Present Ammonia 100 Hydrogen 100 peroxide Example 3 Present Ammonia 100 O.sub.3 30 Example 4 Present Ammonia 100 H.sub.2 1.2 Example 5 Present CO.sub.2 10 Hydrogen 100 peroxide Example 6 Present CO.sub.2 10 O.sub.3 30 Example 7 Present CO.sub.2 10 H.sub.2 1.2

TABLE-US-00002 TABLE 2 Variation in Variation in conductivity- redox potential- imparting adjusting Average substance substance drain water concentration concentration flow rate Example No. (%) (%) (L/min) Comparative <?10 <?10 110 Example 1 Comparative <?10 <?10 110 Example 2 Comparative <?10 <?10 110 Example 3 Comparative <?10 <?10 110 Example 4 Comparative <?10 <?10 110 Example 5 Comparative <?10 <?10 110 Example 6 Comparative <?10 <?10 110 Example 7 Comparative ?200 ?100 0 Example 8 Comparative ?80 ?100 0 Example 9 Example 1 <?10 <?10 30 Example 2 <?10 <?10 30 Example 3 <?10 <?10 30 Example 4 <?10 <?10 30 Example 5 <?10 <?10 30 Example 6 <?10 <?10 30 Example 7 <?10 <?10 30

DESCRIPTION OF REFERENCE NUMERALS

[0075] 1 Functional aqueous solution supply apparatus [0076] 2 Pipe conduit [0077] 3 Replenishment water production unit [0078] 4 Pipe [0079] 5 Storage tank [0080] 6A, 6B, 6C, 6D Single-wafer type washer (use point) [0081] 7 Circulation pipe conduit [0082] 7A, 7B, 7C, 7D Supply pipe [0083] 8A, 8B, 8C, 8D Return pipe [0084] 9 Control means [0085] W Ultrapure water [0086] W1 Washing water (functional aqueous solution)