JP3777451B2 - Ozone water generation method and ozone water production apparatus - Google Patents

Description

  The present invention relates to an ozone water generating method for generating ozone water by adding ozone gas to at least one of pure water or carbonated water, and an ozone water production apparatus. Further, ozone gas in which carbon dioxide gas is added to pure water is added. More particularly, the present invention relates to an ozone water generation method and an ozone water production apparatus for obtaining ozone water to be produced easily and inexpensively.

  Ozone treatment in which ozone gas is brought into contact with a solution to treat the solution has long been used for treating various solutions including water treatment of sewers. Moreover, in recent years, it has come to be widely used from the middle water supply to the water supply. Recently, ozone water obtained by dissolving ozone in pure water has been widely used for wet cleaning of semiconductors and liquid crystals.

  However, in semiconductors and liquid crystals, the ozone water concentration is always stable, and simultaneous use at two or more different concentrations of high and low concentrations is often required. If the above ozone water apparatus is not used, a stable ozone water concentration cannot be obtained, and the cost is very high.

  In addition, depending on how the ozone water was made, the subsequent attenuation of the ozone water concentration changed greatly, and the fluctuation of the ozone water concentration in the actual cleaning tank was very large. For this reason, the ozone water concentration supplied from the apparatus is used for cleaning semiconductors and the like with a margin by supplying it at a concentration much higher than the actually required concentration.

  In addition, it is natural that the ozone water concentration has a margin from the site where it is actually used, and even if the ozone water concentration is high, there is no problem in the current cleaning of semiconductors. I have been.

  However, this does not mean that the degree of cleaning of the surface of the article to be cleaned is constant, and when used for forming a protective oxide film, there is a difference in the thickness of the oxide film due to the difference in ozone water concentration. It sometimes happened.

  Furthermore, in today's use of ozone water, it is used not only for decomposing organic substances, but also for removing metal on the substrate, generating a protective oxide film, and cleaning after patterning. As it comes to be used, it is often used at different ozone water concentrations at the same time, and the limitation of the ozone water concentration range is becoming stricter.

  Recently, as the wiring pitch of semiconductors has become narrower, the quality of pure water used therein has become a problem, and very clean pure water has been required. The water quality of such pure water has approached the limit of 18.24 MΩcm, and TOC and general metal contamination have been required to have a purity up to the detection limit.

  As described above, as the purity of pure water becomes higher, ozone water generation using the pure water has noticeably fluctuated fluctuations in the concentration of ozone water that seems to depend on the quality of the pure water. In general, as the purity of pure water increases, the ozone water concentration tends to decrease. Therefore, recently, when generating ozone water, carbon dioxide gas is added to pure water to make carbonated pure water and then ozone gas is added to generate carbonated ozone water, or carbon dioxide gas is added to pure water. A method of injecting added ozone gas to generate carbonized ozone water has come to be used.

The ozone water to which carbonic acid is added is not affected by the TOC in pure water, so it is possible to easily obtain a very high concentration of ozone water, and the concentration of the generated ozone water is very attenuated. Since there is little attenuation due to the distance to the cleaning tank, high-concentration ozone water can be easily obtained in the cleaning tank (for example, Patent Document 1).
JP 2003-145181 A (page 1 to page 6, FIGS. 1 to 4)

  However, it has been very difficult to provide two or more stable concentrations of ozone water at low cost, and it has not been possible to detect any variation in the concentration of ozone water due to aging of the ozone water device.

  The present invention provides an ozone water generation method and an ozone water production apparatus for solving the above-mentioned problems of the prior art and obtaining ozone water having two or more concentrations that are continuous over a long period of time and always stable. The purpose is to do.

  In order to solve the above problems and achieve the object, the present invention is configured as follows.

The invention according to claim 1 adds ozone gas to at least one of pure water or carbonic acid-containing pure water obtained by dissolving carbon dioxide in pure water,
Also, add ozone gas with carbon dioxide added to pure water,
In the method of generating ozone water,
A low-concentration ozone water generation unit that dissolves the ozone gas and extracts a portion of the ozone gas as low-concentration ozone water in the middle of generating ozone water;
An ozone water generation unit that generates and takes out high-concentration ozone water dissolved to the end,
Ozone gas is dissolved in the low-concentration ozone water supplied from the low-concentration ozone water generation unit in the ozone water generation unit, taken out as high-concentration ozone water, and supplied to places other than the ozone water production device,
Exhaust ozone gas from the ozone water generator is dissolved in pure water at the low-concentration ozone water generator to obtain low-concentration ozone water, and a part is taken out as low-concentration ozone water and supplied to places other than the ozone water production apparatus And supplying the remaining low-concentration ozone water to the ozone water generator,
Towards the low concentration ozone water taken out the halfway, higher concentrations of ozone water by dissolving up to the last concentration is rather low,
The low-concentration ozone water generation unit and the ozone water generation unit dissolve ozone gas through a film to generate ozone water,
Measure the ozone water concentration of each of the low-concentration ozone water taken out along the way and the high-concentration ozone water dissolved to the end, and when the difference becomes large, an alarm predicts in advance the deterioration of the high-concentration side film. It is the ozone water generation method characterized by transmitting .

The invention according to claim 2 adds ozone gas to at least one of pure water or carbonic acid-containing pure water obtained by dissolving carbon dioxide in pure water,
In addition, in an apparatus for generating ozone water by adding ozone gas in which carbon dioxide gas is added to pure water,
A low-concentration ozone water generation unit that dissolves the ozone gas and extracts a portion of the ozone gas as low-concentration ozone water in the middle of generating ozone water;
An ozone water generation unit that generates and takes out high-concentration ozone water dissolved to the end,
Ozone gas is dissolved in the low-concentration ozone water supplied from the low-concentration ozone water generation unit in the ozone water generation unit, taken out as high-concentration ozone water, and supplied to places other than the ozone water production device,
Exhaust ozone gas from the ozone water generator is dissolved in pure water at the low-concentration ozone water generator to obtain low-concentration ozone water, and a part is taken out as low-concentration ozone water and supplied to places other than the ozone water production apparatus And supplying the remaining low-concentration ozone water to the ozone water generator,
Towards the low concentration ozone water taken out the halfway, higher concentrations of ozone water by dissolving up to the last concentration is rather low,
The low-concentration ozone water generation unit and the ozone water generation unit dissolve the ozone gas through a film to generate ozone water,
An ozone water concentration measuring unit for measuring the concentration of each of the low-concentration ozone water taken out in the middle and the high-concentration ozone water dissolved up to the end;
The ozone water concentration measuring unit is an ozone water producing apparatus characterized in that when the difference between the respective ozone water concentrations becomes large, an alarm for predicting in advance the deterioration of the film on the high concentration side is transmitted.

  Hereinafter, the present invention will be described in detail. For example, in the case of an apparatus that supplies ozone water concentrations of 100 mg / l and 10 mg / l at the same time, the cost is reduced to 2/3 when one apparatus is used for two ozone apparatuses.

  In this invention, by supplying two or more ozone waters having different concentrations with a single device, fluctuations in the concentration of the generated ozone water can be suppressed, and stable and inexpensive ozone water generation can be achieved. .

  Next, detailed conditions regarding the ozone water production apparatus according to the present invention will be described. There are several methods for dissolving ozone gas in pure water to make ozone water, and the ozone water concentration varies somewhat depending on the method. However, it is natural that the major factors that determine the concentration of ozone water are the amount of ozone gas and the concentration of ozone gas, but it has recently been found that the quality of pure water is greatly related.

  Here, the pure water has a specific resistance of 1/100 to 1/200 MΩcm, while having a specific resistance of 1 MΩcm or more by removing metal contamination therein.

  In semiconductors, the purity of water is further increased, and the specific resistance is made to be ultrapure water of 18 MΩcm or more. Recently, the purity is further increased and the specific resistance is approaching the limit of 18.24 MΩcm, and TOC and general metal contamination are Ultra-pure water whose purity has been increased to the lower detection limit has been used.

  Usually, ozone water is dissolved in the above-described ultrapure water or ultrapure water to generate ozone water and simultaneously supply it to two or more locations using two ozone water devices. However, since the two ozone water devices are controlled by the respective ozone concentration meters to generate ozone water, the exchange of signals with the cleaning side is very complicated.

  In addition, since control for each ozone water to operate stably is performed by a separate device, it is difficult to make a judgment, and moreover, it is impossible to predict the deterioration of the device over time proactively. .

  However, it is possible to estimate the deterioration of the apparatus over time by measuring the ozone water concentration of each apparatus and comparing it with the previous state.

  For example, as a method for generating ozone water by dissolving ozone gas in pure water, there is a method of dissolving ozone gas in pure water through a membrane. When producing high-concentration ozone water, the membrane is dissolved through many stages.

  Ozone gas and pure water come into contact with each other by so-called counter flow. As a result of several experiments, it has been found that the film in contact with high-concentration ozone gas is more deteriorated with time than the film in contact with low-concentration ozone gas.

Thus, a single apparatus, in contact with a high concentration of ozone gas, as to generate a high concentration ozone water, contact with ozone gas in a low concentration, and thereby generating a low concentration ozone water, ozone water concentration By measuring each ozone water concentration by the measurement unit and comparing it periodically, it becomes possible to predict in advance the deterioration of the membrane on the high concentration side, and by replacing the membrane before it actually deteriorates, the device Can be operated continuously without stopping for a long time.

In the present invention, as a method for generating ozone water having two concentrations in a simple and stable manner, ozone gas is dissolved and a part of the ozone water is taken out while the ozone water is being generated. Ozone water dissolved up to is generated and taken out, and supplied to locations other than the ozone water production apparatus for use .

  With the above configuration, the present invention has the following effects.

  As described above, in the present invention, ozone water having a stable concentration can be obtained at all times. Moreover, high concentration ozone water and low concentration ozone water can be generated simultaneously. Furthermore, it is possible to predict in advance the deterioration due to the dissolved membrane in advance, and by exchanging it, it is possible to obtain an ozone water generator having a stable concentration over a long period of time.

  Hereinafter, embodiments of the ozone water generating method and the ozone water producing apparatus of the present invention will be described. The embodiment of the present invention shows the most preferable mode of the present invention, and the present invention is not limited to this.

  Next, an example of an embodiment according to the present invention will be described based on the attached drawings.

  FIG. 1 is a conceptual diagram of general ozone water generation, and FIG. 2 is a conceptual diagram for supplying ozone water of two different concentrations with one apparatus for ozone water generation according to the embodiment of the present invention. is there.

  In FIG. 1, in the ozone water generation, pure water 1 is guided to the ozone water generation unit 3. Similarly, ozone gas 4 is supplied to the ozone water generator 3. The pure water 1 is converted into ozone water by the supplied ozone gas 4 in the ozone water generation unit 3 and is discharged from the ozone water generation unit 3 and supplied as ozone water 2. Ozone gas that has not become ozone water in the ozone water generation unit 3 is processed in the ozone gas processing unit 5 as exhaust ozone gas.

  In FIG. 2, in the ozone water generation, the pure water 1 is guided to the low-concentration ozone water generation unit 3b. Similarly, the low-concentration ozone water generation unit 3b is supplied with the passing ozone gas 4b via the high-concentration ozone water generation unit 3. The pure water 1 is converted into ozone water by the supplied ozone gas 4 b in the ozone water generation unit 3 and is discharged from the low concentration ozone water generation unit 3 b and supplied as low concentration ozone water 6. Further, the via ozone water 2 b having the same concentration is further guided to the ozone water generating unit 3. Similarly, ozone gas 4 is supplied to the ozone water generator 3. In the ozone water generation unit 3, the via ozone water 2 b becomes high-concentration ozone water by the supplied ozone gas 4 and is discharged from the ozone water generation unit 3 and supplied as ozone water 2. Ozone gas that has not become ozone water in the ozone water generation unit 3 is processed in the ozone gas processing unit 5 as exhaust ozone gas.

  In the ozone water generation unit 3, the ozone water is dissolved by dissolving ozone gas through a film (not shown) to generate ozone water.

  The ozone water concentration of each of the low-concentration ozone water 6 taken out in the middle and the ozone water 2 dissolved to the end is measured by the ozone water concentration measuring unit 10, and an alarm is issued when the difference becomes large.

  1 and 2, ozone gas 4 is added to pure water 1, but ozone gas 4 may be added to carbonated water, or ozone gas 4 may be added to pure water 1 and carbonated water. Further, ozone gas 4 in which carbon dioxide gas is added to pure water 1 may be added.

[Example]
Next, although the Example of the ozone generator concerning this invention is described, this Example does not limit this invention.
Example 1
Ozone water was generated using an apparatus that simultaneously supplied ozone water concentrations of 100 mg / l and 10 mg / l.

  When the concentration of ozone water, which was very stable at the beginning, passed 2 years, the concentration of ozone water decreased to 90 mg / l. However, there was no change in the ozone water concentration of 10 mg / l on the low concentration side.

(Comparative Example 1)
Ozone water generation was performed using two ozone water devices with ozone water concentrations of 100 mg / l and 10 mg / l. The ozone water concentration varied between the two units, and when two years passed, it was not possible to determine whether the ozone water concentration was changed due to deterioration of the film over time at 90 to 100 mg / l and 8 to 10 mg / l, respectively.

  Dissolve ozone gas, take out part of it as ozone water, and use it simultaneously with ozone water dissolved to the end. To obtain ozone water of concentration.

It is a conceptual diagram of general ozone water generation. It is a conceptual diagram which supplies ozone water of two different density | concentration with one apparatus by the ozone water production | generation concerning embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pure water 2 Ozone water 3 Ozone water production | generation part 4 Ozone gas 5 Ozone gas processing part 2b Via ozone water 3b Low concentration ozone water production | generation part 4b Via ozone gas 6 Low concentration ozone water 10 Ozone water concentration measurement part

Claims (2)

Add ozone gas to pure water or at least one of carbonated pure water obtained by dissolving carbon dioxide in pure water,
Also, add ozone gas with carbon dioxide added to pure water,
In the method of generating ozone water,
A low-concentration ozone water generation unit that dissolves the ozone gas and extracts a portion of the ozone gas as low-concentration ozone water in the middle of generating ozone water;
An ozone water generation unit that generates and takes out high-concentration ozone water dissolved to the end,
Ozone gas is dissolved in the low-concentration ozone water supplied from the low-concentration ozone water generation unit in the ozone water generation unit, taken out as high-concentration ozone water, and supplied to places other than the ozone water production device,
Exhaust ozone gas from the ozone water generator is dissolved in pure water at the low-concentration ozone water generator to obtain low-concentration ozone water, and a part is taken out as low-concentration ozone water and supplied to places other than the ozone water production apparatus And supplying the remaining low-concentration ozone water to the ozone water generator,
Towards the low concentration ozone water taken out the halfway, higher concentrations of ozone water by dissolving up to the last concentration is rather low,
The low-concentration ozone water generation unit and the ozone water generation unit dissolve ozone gas through a film to generate ozone water,
Measure the ozone water concentration of each of the low-concentration ozone water taken out along the way and the high-concentration ozone water dissolved to the end, and when the difference becomes large, an alarm predicts in advance the deterioration of the high-concentration side film. A method for generating ozone water characterized by transmitting . Add ozone gas to pure water or at least one of carbonated pure water obtained by dissolving carbon dioxide in pure water,
In addition, in an apparatus for generating ozone water by adding ozone gas in which carbon dioxide gas is added to pure water,
A low-concentration ozone water generation unit that dissolves the ozone gas and extracts a portion of the ozone gas as low-concentration ozone water in the middle of generating ozone water;
An ozone water generation unit that generates and takes out high-concentration ozone water dissolved to the end,
Ozone gas is dissolved in the low-concentration ozone water supplied from the low-concentration ozone water generation unit in the ozone water generation unit, taken out as high-concentration ozone water, and supplied to places other than the ozone water production device,
Exhaust ozone gas from the ozone water generator is dissolved in pure water at the low-concentration ozone water generator to obtain low-concentration ozone water, and a part is taken out as low-concentration ozone water and supplied to places other than the ozone water production apparatus And supplying the remaining low-concentration ozone water to the ozone water generator,
Towards the low concentration ozone water taken out the halfway, higher concentrations of ozone water by dissolving up to the last concentration is rather low,
The low-concentration ozone water generation unit and the ozone water generation unit dissolve the ozone gas through a film to generate ozone water,
An ozone water concentration measuring unit for measuring the concentration of each of the low-concentration ozone water taken out in the middle and the high-concentration ozone water dissolved up to the end;
The ozone water concentration measuring apparatus transmits an alarm for predicting in advance the deterioration of the high-concentration side film when the difference between the ozone water concentrations becomes large .

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