JP2009027023A - Manufacturing method and apparatus for wafer cleaning liquid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method and apparatus for wafer cleaning liquid, capable of manufacturing a sulfuric peroxide aqueous solution by an inexpensive apparatus. <P>SOLUTION: A bipolar film 5 is arranged most closely to a cathode 2, and a cathode chamber 6 is formed between the cathode 2 and the bipolar film 5. From the bipolar film 5 to an anode, a cation exchange film 4 and the bipolar film 5 are arrayed alternately in the order. The bipolar film 5 is arranged most closely to the anode 5. A cation moving chamber 7 is arranged on the side of the cathode 2 of the cation exchange film 4 arranged between a pair of bipolar films 5, and a treating chamber 8 is formed on the side of the anode 3 of the cation exchange film 4. A persulfate aqueous solution inside a tank 15 for circulation is supplied through a pump 16 and piping 11 to each treating chamber 8. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method and apparatus for producing a persulfate aqueous solution for cleaning a wafer such as a silicon wafer, and more particularly, a wafer in which a persulfate aqueous solution is processed by an electrodeionization apparatus to produce a persulfate aqueous solution. The present invention relates to a cleaning liquid manufacturing method and apparatus.

  Concentrated sulfuric acid and hydrogen peroxide mixed solution (SPM) or solution in which ozone gas is blown into concentrated sulfuric acid (SOM) in the cleaning process for peeling and cleaning resist residues, fine particles, metals and natural oxide films in the VLSI manufacturing process Is frequently used. When hydrogen peroxide or ozone is added to high-concentration sulfuric acid, the sulfuric acid is oxidized and caroic acid (peroxomonosulfuric acid) is produced. It is known that caroic acid (peroxomonosulfuric acid) has a high cleaning ability because it emits a strong oxidizing power when self-decomposing, and is useful for cleaning the wafer and the like.

  As peroxosulfuric acid, there is persulfuric acid (peroxodisulfuric acid) in addition to caroic acid, which is useful for cleaning wafers and the like as in caroic acid. As a method for producing persulfuric acid, there is known a method in which an aqueous solution containing sulfate ions is electrolyzed in an electrolytic tank to obtain persulfuric acid-dissolved water and used for washing (see Patent Documents 1 to 3).

JP 2001-192874 A Special table 2003-511555 gazette JP 2006-114880 A

  In SPM, it is necessary to repeat the replenishment of the hydrogen peroxide solution in order to compensate for the amount of decomposition when the caloic acid generated by the hydrogen peroxide solution is self-decomposed and the oxidizing power is reduced. When the sulfuric acid concentration falls below a certain concentration, it is exchanged with a new high concentration sulfuric acid. However, in the above method, since the caroic acid solution is diluted with water in hydrogen peroxide water, it is difficult to maintain the liquid composition constant, and the liquid is discarded and renewed every predetermined time or every processing batch. It is necessary to. For this reason, there is a problem that the cleaning effect is not constant and a large amount of chemicals must be stored. On the other hand, in the SOM, the liquid is not diluted and the liquid renewal cycle can be generally longer than that of the SPM, but the cleaning effect is inferior to that of the SPM.

  Further, in SPM, the amount of caloic acid that can be generated by adding high-concentration sulfuric acid that has filled the cleaning tank once and hydrogen peroxide water several times is small and has a limit. In the SOM method, the generation efficiency of caroic acid with respect to the ozone blowing amount is very low. Therefore, in these methods, the concentration of the generated caroic acid is limited, and the cleaning effect is also limited.

  The method of generating persulfuric acid by electrolytic oxidation of sulfate ion has many advantages because it does not have the disadvantages of SPM and SOM, and the liquid can be recycled. Since it is necessary to configure the apparatus using an eluting electrode (for example, a diamond electrode), the apparatus must be expensive.

  An object of the present invention is to provide a method and an apparatus for producing a wafer cleaning solution that can solve the above-described conventional problems and can produce an aqueous persulfate solution with an inexpensive apparatus.

  The method for producing a wafer cleaning liquid according to claim 1 is to manufacture a wafer cleaning liquid comprising a persulfuric acid aqueous solution by passing the persulfate aqueous solution through an electrodeionization apparatus and removing cations from the persulfate aqueous solution. It is a feature.

  The method for producing a wafer cleaning liquid according to claim 2 is the method according to claim 1, wherein the electrodeionization apparatus includes a cation exchange membrane and a bipolar membrane on the anode side of the cation exchange membrane between the cathode and the anode. An electrodeionization apparatus in which a cation transfer chamber is formed on the cathode side of the cation exchange membrane and a treatment chamber is formed on the anode side of the cation exchange membrane, and a persulfate aqueous solution is supplied to the treatment chamber, By transferring cations from the processing chamber to the cation moving chamber, an aqueous solution of persulfuric acid is generated in the processing chamber, and the aqueous solution of persulfuric acid is allowed to flow out of the processing chamber.

  The method for producing a wafer cleaning liquid according to claim 3 is the method according to claim 1, wherein the electrodeionization apparatus includes a bipolar membrane, a cation exchange membrane on the anode side of the bipolar membrane, and the cation exchange between the cathode and the anode. An anion exchange membrane on the anode side of the membrane, a cation transfer chamber is formed on the cathode side of the cation exchange membrane, a treatment chamber is formed on the anode side of the cation exchange membrane, and on the anode side of the anion exchange membrane An electrodeionization apparatus in which an anion transfer chamber is formed, supplying a persulfate aqueous solution to the treatment chamber, supplying pure water to the anion transfer chamber, and supplying persulfate ions from the treatment chamber to the anion transfer chamber. By moving, an aqueous persulfate solution is generated in the anion transfer chamber, and the aqueous persulfate solution is allowed to flow out of the anion transfer chamber.

  According to a fourth aspect of the present invention, there is provided a method for producing a wafer cleaning liquid according to the second aspect, wherein at least the cation transfer chamber is filled with a conductor.

  According to a fifth aspect of the present invention, there is provided a method for producing a wafer cleaning liquid according to the third aspect, wherein at least the cation transfer chamber or the anion transfer chamber is filled with a conductor.

  A method for producing a wafer cleaning liquid according to a sixth aspect is characterized in that, in any one of the first to third aspects, the temperature of the aqueous persulfate solution supplied to the electrodeionization apparatus is 60 ° C. or lower. is there.

  The apparatus for producing a wafer cleaning liquid according to claim 7 comprises an electrodeionization device, a supply means for supplying an aqueous solution of persulfate to the electrodeionization device, and an extraction means for taking out the aqueous solution of persulfate from the electrodeionization device. It will be.

  The apparatus for producing a wafer cleaning liquid according to claim 8 is the apparatus according to claim 5, wherein the electrodeionization apparatus includes a cation exchange membrane and a bipolar membrane on the anode side of the cation exchange membrane between the cathode and the anode. An electrodeionization apparatus in which a cation transfer chamber is formed on the cathode side of the cation exchange membrane, a treatment chamber is formed on the anode side of the cation exchange membrane, and each chamber is filled with a conductor. Is supplied with a persulfate aqueous solution, and the persulfate aqueous solution flows out of the treatment chamber.

  The apparatus for producing a wafer cleaning liquid according to claim 9 is the method according to claim 5, wherein the electrodeionization apparatus includes a bipolar membrane, a cation exchange membrane on the anode side of the bipolar membrane, and the cation exchange between the cathode and the anode. An anion exchange membrane on the anode side of the membrane, a cation transfer chamber is formed on the cathode side of the cation exchange membrane, a treatment chamber is formed on the anode side of the cation exchange membrane, and on the anode side of the anion exchange membrane An electrodeionization apparatus in which anion transfer chambers are formed and each chamber is filled with a conductor, wherein a persulfate aqueous solution is supplied to the treatment chamber, and the persulfate aqueous solution flows out of the treatment chamber. To do.

  A wafer cleaning liquid manufacturing apparatus according to a tenth aspect includes the liquid circulation tank according to the sixth aspect, wherein the supply means supplies the persulfate aqueous solution in the tank to the electrodeionization apparatus. The extraction means is configured to return the persulfuric acid aqueous solution from the electrodeionization apparatus to the tank.

  The apparatus for producing a wafer cleaning liquid according to claim 11 is characterized in that, in claim 8, the tank has a sensor for measuring a cation concentration of a salt in the tank, and the supply means and take-out when the cation concentration of the sensor is higher than a predetermined value. The liquid in the tank is circulated through the electrodeionization device by means, and when the cation concentration of the sensor is lower than the predetermined value, the circulation water is stopped and the persulfuric acid aqueous solution in the tank is passed to the wafer cleaning device. It is characterized by having water flow control means for sending water.

  The apparatus for producing a wafer cleaning liquid according to a twelfth aspect of the present invention includes the cooling means according to any one of the fifth to ninth aspects, wherein the temperature of the persulfate aqueous solution supplied to the electrodeionization apparatus is 60 ° C. or lower. It is characterized by that.

  The bipolar membrane is a kind of composite membrane having a structure in which a cation exchange membrane and an anion exchange membrane are bonded together. Bipolar membranes have been widely used as a separation membrane for electrolysis of water or as a separation membrane for regenerating acid and alkali from an aqueous solution of a salt that is a neutralized product of acid and alkali. It is an ion exchange membrane, and various manufacturing methods have been proposed. In the present invention, a bipolar membrane having a cation exchange membrane on the cathode side and an anion exchange membrane on the anode side is used.

  According to the present invention, an aqueous solution of persulfuric acid can be produced by an electrodeionization apparatus that has a lower apparatus configuration cost than an electrolysis apparatus.

  By having a bipolar membrane as an electrodeionization apparatus, persulfate ions can be more selectively separated and recovered from a persulfate aqueous solution.

  By reducing the temperature of the aqueous solution of persulfate supplied to the electrodeionization device to 60 ° C. or lower, the temperature inside the electrodeionization device can be lowered, and decomposition of persulfuric acid can be suppressed. Oxidative deterioration inside the electrodeionization apparatus due to radicals such as sulfuric acid radicals generated by self-decomposition can be suppressed.

  In addition, by installing a circulation tank as in claim 10 and circulating the persulfate aqueous solution, the cation is sufficiently removed from the persulfate aqueous solution to produce a persulfate aqueous solution having a low cation concentration. Can do.

  According to the eleventh aspect, by performing the circulation process while detecting the cation concentration in the tank by the sensor, the aqueous solution of persulfuric acid having the cation concentration lower than the predetermined value can be supplied to the wafer cleaning apparatus.

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

  FIG. 1 is a system diagram showing a method and apparatus for producing a wafer cleaning liquid according to the first embodiment.

  The electrodeionization apparatus 1 arranges a cation exchange membrane 4 and a bipolar membrane 5 between the cathode 2 and the anode 3 in this order from the cathode 2 side to the anode 3 side, thereby treating the cation transfer chamber 7 and the anode 3. The chamber 8 and the anode chamber 9 are partitioned and each chamber 7, 8, 9 is filled with a conductor (not shown).

  A bipolar membrane may be disposed between the cation transfer chamber 7 and the cathode 2, and the cathode chamber may be partitioned between the cation transfer chamber 7 and the cathode.

A persulfate aqueous solution is supplied from the raw water tank 10 to the processing chamber 8 through a pipe 11.
In the raw water tank, temperature adjusting means (not shown) for adjusting the persulfate aqueous solution to be in a predetermined temperature range is provided.

Cations such as sodium permeate the cation exchange membrane and migrate from the processing chamber 8 to the cation transfer chamber 7, but anions (persulfate ions) do not permeate the bipolar membrane 5 and remain in the processing chamber 8. For this reason, the aqueous solution of persulfuric acid flowing out from the treatment chamber 8 is collected in the treated water tank 13 via the pipe 12.
The treated water tank 13 is provided with temperature adjusting means (not shown) as in the raw water tank, and the persulfuric acid solution is adjusted to a predetermined temperature.

  Examples of the persulfate include sodium persulfate, potassium persulfate, and ammonium persulfate. Sodium persulfate is particularly preferable. The concentration of the persulfate aqueous solution is preferably about 50 to 300 wt%, particularly about 100 to 150 wt% from the viewpoint of long-term stability.

  As a conductor filled in each chamber, a cation exchange resin can be adopted in all the chambers. However, the cathode chamber and the anode chamber separated by the bipolar membrane may be filled with a conductor other than the cation exchange resin (for example, a metal conductor such as SUS) as long as conductivity is ensured.

The water flow LV to the processing chamber 8 is preferably about 3 to 5 m / h. An acid such as sulfuric acid can be passed through the cation transfer chamber 7 and the anode chamber 9 respectively. However, when the concentration of persulfate exceeds 5%, the LV is increased or the salt concentration is suppressed so that the heat of neutralization does not extremely increase. It is also possible to pass pure water. When sulfuric acid is used as the acid, even if a slight amount of sulfuric acid permeates from the bipolar membrane and enters the process, it does not affect the composition of the persulfuric acid solution. The pure water in the anode chamber 9 can be circulated. However, from the viewpoint of long-term stability, it is better to process in one pass so that the oxidizing substance is not concentrated. From the cation transfer chamber 7, an aqueous NaOH solution or an aqueous solution of a neutralized product by acid (Na ₂ SO ₄ or the like) flows out.

  FIG. 2 is a system diagram of a wafer cleaning solution manufacturing method and apparatus using an electrodeionization apparatus 1A in which a plurality of cation exchange membranes and bipolar membranes are alternately arranged between a cathode 2 and an anode 3. .

  A bipolar film 5 is disposed closest to the cathode 2, and a cathode chamber 6 is formed between the cathode 2 and the bipolar film 5. The cation exchange membranes 4 and the bipolar membranes 5 are alternately arranged in this order from the bipolar membrane 5 toward the anode. The bipolar film 5 is disposed closest to the anode 5. A cation transfer chamber 7 is disposed on the cathode 2 side of the cation exchange membrane 4 disposed between the pair of bipolar membranes 5, and a treatment chamber 8 is formed on the anode 3 side of the cation exchange membrane 4. An anode chamber 9 is formed between the bipolar film 5 closest to the anode 5 and the anode 5. Pure water is circulated through the cathode chamber 6 and the anode chamber 9, respectively. Pure water is supplied to the cation transfer chamber 7, and an aqueous NaOH solution flows out of each cation transfer chamber 7.

The persulfate aqueous solution in the circulation tank 15 is supplied to each processing chamber 8 via the pump 16 and the pipe 11. As in the case of FIG. 1, cations pass through the cation exchange membrane 4 and migrate from each processing chamber 8 to the cation transfer chamber 7, and anions (persulfate ions) that cannot permeate the bipolar membrane 5 are in the processing chamber 8. The persulfuric acid aqueous solution flows out from each processing chamber 8.
The circulation tank 15 is provided with temperature adjusting means (not shown), and the persulfate aqueous solution is adjusted to a predetermined temperature.

  This persulfuric acid aqueous solution returns to the circulation tank 15 via the pipe 13. The circulation tank 15 is provided with a sensor 17 for measuring the persulfate concentration. The circulation tank 15 is connected with a pipe 18 for supplying the aqueous persulfuric acid solution to the wafer cleaning process, and a valve 19 and a pump 20 are provided on the pipe 18. Examples of the sensor 17 include an ion electrode, a pH meter, and a conductivity meter.

  At the start of operation of the apparatus shown in FIG. 2, an aqueous sodium persulfate solution is stored in the circulation tank 15, the valve 19 is closed, the pump 20 is stopped, and the pump 16 is operated. Thereby, the sodium persulfate aqueous solution in the circulation tank 15 is passed through the electrodeionization apparatus 1A, and the aqueous solution of persulfate returns from the electrodeionization apparatus 1A to the circulation tank 15 via the pipe 13. Therefore, when the operation is continued, the sodium concentration of the aqueous solution in the circulation tank 15 gradually decreases. When the sodium concentration detected by the sensor 17 becomes a predetermined value or less, the pump 16 is stopped, the valve 19 is opened, the pump 20 is operated, and the persulfuric acid aqueous solution is washed from the circulation tank 15 to the wafer. Send to process.

  FIG. 3 shows an anion exchange membrane 21 disposed on the anode side of the cation exchange membrane 4 between a pair of bipolar membranes 5 in FIG. Thereby, between the pair of bipolar membranes 5, 5, a cation transfer chamber 7 is formed between the cathode side bipolar membrane 5 and the cation exchange membrane 4, and between the cation exchange membrane 4 and the anion exchange membrane 21. A treatment chamber 22 is formed, and an anion transfer chamber 23 is formed between the anion exchange membrane 21 and the anode-side bipolar membrane 5.

  In FIG. 3, while the persulfate aqueous solution supplied to the processing chamber 22 flows in the processing chamber 22, cations in the persulfate aqueous solution permeate the cation exchange membrane 4 and migrate to the cation transfer chamber 7. Then, the anion passes through the anion exchange membrane 21 and moves to the anion transfer chamber 23, and the aqueous persulfate solution flows out from the anion transfer chamber 23. This persulfuric acid aqueous solution is sent to the wafer cleaning process via the pipe 25.

  Deionized water flows out of the processing chamber 22. The deionized water is circulated to the inlet of the processing chamber 22 through the pipe 26, and a high concentration persulfate aqueous solution is added on the way.

  Note that pure water is supplied to each of the electrode chambers 6 and 9, the cation transfer chamber 7, and the anion transfer chamber 23. Since pure water flows out from the electrode chambers 6 and 9, they are reused. An aqueous NaOH solution flows out from the cation transfer chamber 7. As described above, the aqueous solution of persulfuric acid flows out from the anion transfer chamber 23.

In addition, persulfuric acid decomposes at room temperature as follows to produce caroic acid and sulfuric acid.
H ₂ S ₂ O ₈ + H ₂ O → H ₂ SO ₅ + H ₂ SO ₄
Caroic acid is further decomposed by water to produce hydrogen peroxide and sulfuric acid.
H ₂ SO ₅ + H ₂ O → H ₂ O ₂ + H ₂ SO ₄
On the other hand, the following reaction occurs at high temperatures.
H ₂ S ₂ O ₈ → 2H ⁺ + S ₂ O ₈ ²⁻ (persulfate ion)
S ₂ O ₈ ²⁻ → 2SO ₄ ⁻ (sulfuric acid radical)
Even after conversion to caroic acid, sulfuric acid radicals are produced in the next reaction. (Slower reaction than above)
H ₂ SO ₅ ²⁻ → SO ₄ ⁻ · + OH ·
This reaction requires large heat energy to stabilize the generated radicals. Therefore, it is a characteristic reaction in a high temperature region, and the reaction efficiency is considered to be extremely low at normal temperature and pressure. Even if the reaction occurs, the generated radical reacts with the radical in the immediate vicinity and is deactivated. In other words, the type of reaction can be controlled by controlling the temperature of the reaction environment.

As described above, when desalting persulfate, it is necessary to carry out in a predetermined low temperature range in order to suppress the formation of caroic acid, hydrogen peroxide, perfused acid ions, and sulfuric acid radicals from the generated persulfuric acid. Therefore, it is necessary to maintain the processing chamber temperature inside the electrodeionization apparatus at a low temperature. As a result, it is possible to maintain a high concentration of persulfuric acid and to prevent oxidative degradation inside the device due to radicals such as sulfuric acid radicals generated by the self-decomposition of persulfuric acid. Can be processed. The upper limit value of the temperature in the predetermined low temperature range is preferably 60 ° C. or less in view of the heat resistance of the ion exchange membrane, and further considering the corrosion resistance of the ion exchange membrane, it is 40 ° C. or less in terms of long-term stability and safety. To more preferable. Further, the lower limit of the temperature is not particularly limited as long as it freezes and does not inhibit water flow.
The installation location of the temperature adjusting means is not particularly limited, and may be provided in a tank in the line, or a heat exchanger may be provided in the line.

If the temperature of the inside of the electrodeionization apparatus is controlled, there will be no problem of corrosion. However, if discharged from the electrodeionization apparatus, members such as piping may be corroded due to the generation of caloic acid or superfluous acid ions. Therefore, it is desirable to generate persulfuric acid as close as possible to the point of use.
In addition, when using it for wafer cleaning, high concentration sulfuric acid is required, and since a predetermined high temperature environment is required, a persulfuric acid solution and high temperature high concentration sulfuric acid were mixed to increase the temperature and increase the concentration of sulfuric acid. It is desirable to use for wafer cleaning above. At this time, the temperature of the high-concentration sulfuric acid is preferably about 120 to 170 ° C., and the concentration is preferably 90 wt% or more. The generated aqueous persulfuric acid solution contains a large amount of water, so that when it is mixed with high-concentration sulfuric acid, heat of dissolution is generated and the temperature is raised. The mixing ratio is preferably about 1: 1 to 2: 1.
An alkaline aqueous solution such as an aqueous NaOH solution discharged from the anion transfer chamber of the electrodeionization apparatus of the present invention can be mixed with a used sulfuric acid solution, neutralized and discharged out of the system.
In the present invention, since sulfuric acid cannot be recycled, it is suitable for single-wafer cleaning using a cleaning solution efficiently.

It is a systematic diagram which shows the manufacturing method and apparatus of the wafer cleaning liquid which concern on embodiment. It is a systematic diagram which shows the manufacturing method and apparatus of the wafer cleaning liquid which concern on another embodiment. It is a systematic diagram which shows the manufacturing method and apparatus of the wafer cleaning liquid which concern on another embodiment.

Explanation of symbols

1, 1A, 1B Electrodeionization equipment 2 Cathode 3 Anode 4 Cation exchange membrane 5 Bipolar membrane 6 Cathode chamber 7 Cation transfer chamber 8 Treatment chamber 9 Anode chamber 15 Tank for circulation 17 Sodium sensor 21 Anion exchange membrane 22 Treatment chamber 23 Anion migration Room

Claims (12)

  A method for producing a wafer cleaning liquid, comprising: passing a persulfate aqueous solution through an electrodeionization apparatus and removing a cation from the persulfate aqueous solution to produce a wafer cleaning liquid comprising the persulfate aqueous solution. In claim 1,
In the electrodeionization apparatus, a cation exchange membrane and a bipolar membrane on the anode side of the cation exchange membrane are disposed between the cathode and the anode, and a cation transfer chamber is formed on the cathode side of the cation exchange membrane, An electrodeionization apparatus in which a treatment chamber is formed on the anode side of the cation exchange membrane,
Supplying a persulfate aqueous solution to the processing chamber, and generating a persulfate aqueous solution in the processing chamber by moving cations from the processing chamber to the cation moving chamber;
A method for producing a wafer cleaning liquid, wherein a persulfuric acid aqueous solution is allowed to flow out of the processing chamber. In claim 1,
In the electrodeionization apparatus, a bipolar membrane, a cation exchange membrane on the anode side of the bipolar membrane, and an anion exchange membrane on the anode side of the cation exchange membrane are arranged between the cathode and the anode, and the cation exchange An electrodeionization apparatus in which a cation transfer chamber is formed on the cathode side of the membrane, a treatment chamber is formed on the anode side of the cation exchange membrane, and an anion transfer chamber is formed on the anode side of the anion exchange membrane,
The aqueous solution of persulfate is supplied to the treatment chamber and pure water is supplied to the anion transfer chamber. By moving persulfate ions from the treatment chamber to the anion transfer chamber, the aqueous solution of persulfate is transferred into the anion transfer chamber. Generated,
A method for producing a wafer cleaning solution, wherein an aqueous persulfate solution is allowed to flow out of the anion transfer chamber.   3. The method for producing a wafer cleaning liquid according to claim 2, wherein at least the cation moving chamber is filled with a conductor.   4. The method for producing a wafer cleaning solution according to claim 3, wherein at least the cation transfer chamber or the anion transfer chamber is filled with a conductor.   4. The method for producing a wafer cleaning liquid according to claim 1, wherein the temperature of the persulfate aqueous solution supplied to the electrodeionization apparatus is 60 [deg.] C. or less. An electrodeionization device;
Supply means for supplying an aqueous persulfate solution to the electrodeionization device;
An apparatus for producing a wafer cleaning liquid, comprising an extraction means for taking out a persulfuric acid aqueous solution from the electrodeionization apparatus. In claim 5,
In the electrodeionization apparatus, a cation exchange membrane and a bipolar membrane on the anode side of the cation exchange membrane are disposed between the cathode and the anode, and a cation transfer chamber is formed on the cathode side of the cation exchange membrane, An electrodeionization apparatus in which a treatment chamber is formed on the anode side of the cation exchange membrane, and each chamber is filled with a conductor.
An aqueous persulfate solution is supplied to the treatment chamber;
An apparatus for producing a wafer cleaning liquid, wherein an aqueous persulfate solution flows out of the processing chamber. In claim 5,
In the electrodeionization apparatus, a bipolar membrane, a cation exchange membrane on the anode side of the bipolar membrane, and an anion exchange membrane on the anode side of the cation exchange membrane are arranged between the cathode and the anode, and the cation exchange A cation transfer chamber is formed on the cathode side of the membrane, a treatment chamber is formed on the anode side of the cation exchange membrane, an anion transfer chamber is formed on the anode side of the anion exchange membrane, and each chamber is filled with a conductor. Is an electrodeionization device,
An aqueous persulfate solution is supplied to the treatment chamber;
An apparatus for producing a wafer cleaning liquid, wherein an aqueous persulfate solution flows out of the processing chamber. In Claim 6, the tank for liquid circulation is provided,
The supply means supplies the aqueous solution of persulfate in the tank to the electrodeionization device,
The apparatus for producing a wafer cleaning liquid, wherein the take-out means is configured to return the persulfuric acid aqueous solution from the electrodeionization apparatus to the tank. The sensor according to claim 8, wherein the tank measures a cation concentration of a salt in the tank.
When the cation concentration of the sensor is higher than a predetermined value, the liquid in the tank is circulated through the electrodeionization device by the supply means and the extraction means, and when the cation concentration of the sensor is lower than the predetermined value, the circulation is performed. An apparatus for producing a wafer cleaning liquid, comprising a water flow control means for stopping water flow and feeding a persulfuric acid aqueous solution in a tank to a wafer cleaning apparatus.   10. The wafer cleaning liquid manufacturing apparatus according to claim 5, further comprising cooling means for setting the temperature of the persulfate aqueous solution supplied to the electrodeionization apparatus to 60 ° C. or less. .

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