JPWO2015125739A1 - Hydroxyl radical-containing water supply device and hydroxyl radical-containing water supply method - Google Patents

Abstract

Provided are a hydroxyl radical-containing water supply device and a hydroxyl radical-containing water supply method capable of supplying a higher concentration of hydroxyl radicals to a use point by making the length of a pipe for supplying radical water variable. Ozone-containing water supply path (3) for supplying ozone-containing water in which ozone and an additive that suppresses decomposition of ozone are dissolved in pure water, and the supply path (3) are provided with the ozone-containing water. A generation means (4) for adding hydrogen peroxide to generate hydroxyl radical-containing water, and a hydroxyl radical-containing water supply channel (5) for transferring and supplying the generated hydroxyl radical-containing water to a use point are provided. The hydroxyl radical-containing water supply apparatus is characterized by comprising pipe length variable means (6) capable of substantially changing the pipe length of the hydroxyl radical-containing water supply path (5).

Description

  The present invention relates to a hydroxyl radical-containing water supply apparatus and a hydroxyl radical-containing water supply method, and is a technique useful for supplying hydroxyl radical-containing water having a desired concentration in a semiconductor cleaning process or the like.

  Accelerated oxidation treatment (AOP) generates active radical species with strong oxidizing power such as hydroxyl radicals by using ozonolysis catalyst solution such as ozone and hydrogen peroxide, and physicochemical treatment techniques such as ultraviolet rays. This is a method for processing an object. In recent years, such accelerated oxidation treatment has been adopted not only in water treatment but also in fields such as semiconductor cleaning processes.

  For example, Patent Document 1 below proposes a cleaning method in which hydrogen peroxide water is added to ozone water alone, and further, an ultrasonic wave is applied to generate hydroxyl radicals. In this method, it is said that the ozone concentration may be detected by a dissolved ozone concentration detector and fed back to the ozone generator, but the radical concentration is not measured.

  Patent Document 2 listed below discloses a method for adjusting the radical concentration of hydroxyl radical-containing water generated by radical generating means based on the measurement result of the hydroxyl radical concentration in a hydroxyl radical supply apparatus used in a semiconductor cleaning process or the like. Has been proposed.

JP 2000-325902 A JP 2011-75449 A

  However, there is room for improvement because the generated hydroxyl radicals may not be efficiently used for a semiconductor cleaning process or the like simply by measuring and adjusting the radical concentration in-line in this way. In other words, according to the study by the present inventors, the reaction of dissolved ozone and hydrogen peroxide solution has a radical concentration that is instantaneously maximized if it can be completely mixed instantaneously. It was found that the maximum radical concentration was delayed by several seconds from the time of mixing with the hydrogen peroxide solution. For this reason, it has been found that when the time to the use point determined from the supply speed of the treatment liquid and the pipe length is fixed, the radical water having the maximum radical concentration cannot be used in many cases.

Accordingly, an object of the present invention is to provide a hydroxyl radical-containing water supply device and a hydroxyl radical-containing water supply capable of supplying a higher concentration of hydroxyl radicals to a point of use by making the length of a pipe for supplying radical water variable. It is to provide a method.
Radical water and hydroxyl radical-containing water are synonymous and refer to pure water containing hydroxyl radical. In addition to hydroxyl radical, water solubility such as superoxide, hydroperoxyl radical, hydrotrioxy radical, etc. You may contain a radical.

  The above object is achieved by the present invention as follows.

That is, the hydroxyl radical-containing water supply device of the present invention is a supply path for ozone-containing water that supplies ozone-containing water in which ozone and an additive that suppresses decomposition of ozone are dissolved in pure water;
A generating means provided in the supply path for adding an ozone decomposition catalyst solution to the ozone-containing water to generate hydroxyl radical-containing water;
In a hydroxyl radical-containing water supply device comprising: a hydroxyl radical-containing water supply path that transports and supplies the generated hydroxyl radical-containing water to a use point;
A pipe length variable means capable of substantially changing the pipe length of the hydroxyl radical-containing water supply path is provided.

  According to the hydroxyl radical-containing water supply device of the present invention, the hydroxyl radical-containing water can be generated by adding the ozone decomposition catalyst solution to the ozone-containing water by the generating means provided in the ozone-containing water supply path. In that case, since the additive substance which suppresses decomposition | disassembly of ozone is contained in ozone-containing water, the density | concentration of the produced hydroxyl radical can be maintained for a longer time.

  According to the study by the present inventors, the reaction of dissolved ozone and the ozonolysis catalyst solution instantaneously reaches a maximum value if the complete mixing can be performed instantaneously. As shown in FIG. 2, it was found that the maximum radical concentration was delayed by several seconds from the time when the ozone decomposition catalyst solution was mixed. Also, since the reaction rate and mixing state with dissolved ozone differ depending on the concentration of the ozone decomposition catalyst liquid to be mixed, the time from the point of injection of the ozone decomposition catalyst liquid to the maximum radical concentration is the time of the ozone decomposition catalyst liquid to be injected Varies with concentration.

  In the present invention, since the pipe length variable means capable of substantially changing the pipe length of the supply path of the hydroxyl radical-containing water is provided, a higher concentration of hydroxyl radical can be supplied to the use point. As a result, it is possible to provide a hydroxyl radical-containing water supply device that can supply a higher concentration of hydroxyl radicals to the use point by making the length of the piping for supplying radical water variable.

  In the above, based on the concentration measurement means for measuring the concentration of the hydroxyl radical-containing water provided in the hydroxyl radical-containing water supply path, and the concentration of the hydroxyl radical-containing water measured by the concentration measurement means, its concentration It is preferable to provide a control means for adjusting the generating means so that the value approaches the set value. Since the concentration measuring means provided in the supply path for hydroxyl radical-containing water can measure the concentration of hydroxyl radical-containing water in-line, while producing hydroxyl radical-containing water at a more stable concentration by the control means, A higher concentration of hydroxyl radicals can be supplied to the point of use.

  The control means may operate the pipe length varying means and the generating means based on the concentration of hydroxyl radical-containing water necessary for the treatment and the concentration of hydroxyl radical-containing water measured by the concentration measuring means. preferable. In particular, the control means operates the pipe length varying means in advance according to a predetermined chart according to the concentration of hydroxyl radical-containing water necessary for the treatment, and the hydroxyl radical-containing water measured by the concentration measuring means. It is preferable to operate the generating means based on the concentration. By this configuration, following the required concentration of hydroxyl radical-containing water and fluctuations in its concentration, the piping length of the supply path of hydroxyl radical-containing water is changed, and the flow rate of the ozone decomposition catalyst liquid is controlled. A high concentration of hydroxyl radicals can be supplied to the point of use.

  The additive substance is preferably at least one additive substance selected from the group consisting of a water-soluble organic substance, an inorganic acid, a salt of the inorganic acid, and hydrazine. These substances can maintain the concentration of generated hydroxyl radicals for a longer time by suppressing the decomposition of ozone. This allows a higher concentration of hydroxyl radicals to be supplied to the point of use.

  The pipe length varying means preferably has a valve mechanism capable of changing a mixing position at which the ozone decomposition catalyst solution is added to the hydroxyl radical-containing water. Such a valve mechanism can substantially change the length of the piping of the supply path of the hydroxyl radical-containing water using opening and closing of the valve.

Meanwhile, the hydroxyl radical-containing water supply method of the present invention adds ozone decomposition catalyst liquid to the ozone-containing water while supplying ozone-containing water in which ozone and an additive that suppresses decomposition of ozone are dissolved in pure water. In the method for supplying hydroxyl radical-containing water, the generated hydroxyl radical-containing water is transferred to the use point and supplied to the use point while generating the hydroxyl radical-containing water by the generating means.
The hydroxyl radical-containing water is supplied through a pipe length variable means capable of substantially changing the pipe length of the supply path.

  According to the hydroxyl radical-containing water supply method of the present invention, it is possible to supply a higher concentration of hydroxyl radicals to the point of use by making the length of the pipe for supplying radical water variable by the above-described effects. A water supply method can be provided.

  In the above, the generating unit measures the concentration of the hydroxyl radical-containing water with a concentration measuring unit and, based on the concentration of the hydroxyl radical-containing water measured with the concentration measuring unit, the concentration unit approaches the set value. It is preferable to perform control to adjust the value. Since the concentration measurement means can measure the concentration of hydroxyl radical-containing water in-line, by adjusting the generation means based on that, while generating hydroxyl radical-containing water at a more stable concentration, The hydroxyl radical can be supplied to the point of use.

  Further, the concentration of the hydroxyl radical-containing water is measured by a concentration measuring means, and the pipe length is determined based on the concentration of hydroxyl radical-containing water necessary for the treatment and the concentration of hydroxyl radical-containing water measured by the concentration measuring means. It is preferable to perform control for operating the variable means and the generating means. In particular, according to the concentration of hydroxyl radical-containing water necessary for treatment, according to a predetermined chart, the pipe length variable means is operated in advance, and based on the concentration of hydroxyl radical-containing water measured by the concentration measuring means. It is preferable to perform control for operating the generating means. By this configuration, following the required concentration of hydroxyl radical-containing water and fluctuations in its concentration, the piping length of the supply path of hydroxyl radical-containing water is changed, and the flow rate of the ozone decomposition catalyst liquid is controlled. A high concentration of hydroxyl radicals can be supplied to the point of use.

  The additive substance is preferably at least one additive substance selected from the group consisting of a water-soluble organic substance, an inorganic acid, a salt of the inorganic acid, and hydrazine. These substances can maintain the concentration of generated hydroxyl radicals for a longer time by suppressing the decomposition of ozone. This allows a higher concentration of hydroxyl radicals to be supplied to the point of use.

  Moreover, it is preferable that the said pipe length variable means has a valve mechanism which can change the mixing position which adds an ozone decomposition catalyst liquid to the said hydroxyl radical containing water. Such a valve mechanism can substantially change the length of the piping of the supply path of the hydroxyl radical-containing water using opening and closing of the valve.

The schematic block diagram which shows an example of the hydroxyl radical containing water supply apparatus of this invention notionally The graph for demonstrating the effect of the hydroxyl radical containing water supply apparatus of this invention Device configuration diagram showing an example of a hydroxyl radical-containing water supply device of the present invention The perspective view which shows an example of the principal part of the hydroxyl radical containing water supply apparatus of this invention The perspective view which shows the other example of the principal part of the hydroxyl radical containing water supply apparatus of this invention.

  FIG. 1 conceptually shows an example of the hydroxyl radical-containing water supply device of the present invention. As shown in FIG. 1, the apparatus of the present invention includes an ozone-containing water supply path 3 for supplying ozone-containing water in which ozone and an additive substance that suppresses decomposition of ozone are dissolved in pure water, and the supply path 3. And generating means 4 for adding hydroxyl radical-containing water (hereinafter sometimes referred to as “radical water”) by adding an ozone decomposition catalyst solution to the ozone-containing water, and the generated radical water up to the use point A radical water supply path 5 that is transported and supplied.

  The supply path 3 for ozone-containing water is a path for supplying ozone-containing water containing an additive substance. The ozone-containing water is added to, for example, ozone water generated by the ozone water generation means 1 by the additive substance mixing means 2. It can be generated by adding substances.

  The apparatus of the present invention is characterized in that the radical water supply path 5 is provided with pipe length variable means 6 capable of substantially changing the pipe length of the radical water supply path 5. In the illustrated example, the pipe length varying means 6 is provided at the upstream end of the radical water supply path 5, but the pipe length varying means 6 may be provided at an intermediate position or downstream end of the supply path 5. Is possible.

  In the present invention, it is also possible to provide concentration measuring means 7 for measuring the concentration of radical water in the radical water supply path 5. In the illustrated example, the concentration measuring means 7 is provided on the downstream side of the pipe length varying means 6, but it is also possible to provide the concentration measuring means 7 on the upstream side of the pipe length varying means 6.

  Hereinafter, based on FIG. 3, the hydroxyl radical containing water supply apparatus of this invention is demonstrated more concretely.

  The ozone water generating means 1 in this embodiment dissolves ozone in an oxygen cylinder 1a that supplies oxygen, an ozone generator 1b that generates ozone using supplied oxygen, and pure water supplied from a pure water supply device. And an ozone dissolver 1c.

  Pure water is water from which impurities have been removed, and usually water having an electrical resistivity of 15 MΩ · cm or more is used. From the viewpoint of using radical water as a cleaning liquid for electronic parts, semiconductors, liquid crystal related parts and the like (hereinafter referred to as electronic parts), ultrapure water having an electric resistivity of 17 MΩ · cm or more is preferably used. The electrical resistivity can be measured using a commercially available specific resistivity meter.

  The ozone generator 1b is a device that can use a known ozone generator such as an ozonizer, is connected to the oxygen cylinder 1a, and generates ozone from oxygen supplied from the oxygen cylinder 1a. Examples of the ozone generator 1b include a general-purpose water-cooled ozone generator and a silent discharge type ozone generator, and are commercially available from Sumitomo Precision Industries, Regal Joint, Ecodesign, and the like.

  The ozone dissolver 1c can dissolve ozone by, for example, filling a solvent (for example, pure water) therein and supplying ozone generated by the ozone generator 1b therein.

  Ozone is usually dissolved so that the concentration with respect to pure water is, for example, 1 to 400 ppm, preferably 1 to 100 ppm. The concentration of ozone can be measured by, for example, an absorptiometer “Water Riser” (manufactured by Kurashiki Boseki Co., Ltd.), an in-line type dissolved ozone monitor (manufactured by Sugawara Jitsugyo Co., Ltd.), or the like.

  The ozone decomposer 1d is a device that decomposes ozone contained in the gas discharged from the ozone dissolver 1c and discharges the gas. For example, the ozonolysis device 1d includes a thermal decomposition method using a high-temperature heater, an adsorption method using activated carbon, and the like. The valves V1 to V4 are used when starting and stopping each of these devices. In addition, the supply path 3 of the ozone-containing water before the additive substance is added is provided with a filter F1 for filtering and removing particles and the like.

  The additive substance mixing means 2 in this embodiment includes an additive substance tank 2a for storing additive substances, a pump 2b for feeding additive substances, and a filter F2 for filtering and removing particles and the like. In this embodiment, the additive substance is added to the supply path 3 of the ozone-containing water via the valve V6, but it is also possible to circulate the additive substance to the additive substance tank 2a via the valve V5. The valve V7 is a flow rate adjusting valve for automatically adjusting the addition amount based on the result of the flow meter G1 that measures the liquid feeding flow rate, thereby allowing an appropriate amount of the additive substance to be added. The valve V7 may be a flow rate adjusting valve that manually adjusts the amount of addition. In this case, based on the result of the flow meter G1, the stroke control of the pump 2b that is a diaphragm pump or a bellows pump, or The number of discharges per unit time may be controlled, and in the case of a rotary pump (spiral pump), the rotational speed may be controlled by an inverter or the like.

  The order of dissolving ozone and additive substances in pure water is not particularly limited as long as these two components are added to the same system. In this embodiment, (1) ozone and additive substances are added and dissolved in this order in pure water, but (2) additive substances and ozone may be added and dissolved in pure water in this order. (3) Ozone and additive substances may be simultaneously added to pure water and dissolved. In particular, it is preferable to employ the above order (1) from the viewpoints of higher ozone concentration and self-degradability.

  In the supply path 3 of the ozone-containing water after the additive substance has been added, a mixer M1 for stirring the ozone-containing water, a tank 3a for storing the ozone-containing water, and a tank for circulating the ozone-containing water. A pump 3b, a supply header 3c for distributing ozone-containing water to each use point, and a circulation path for circulating the ozone-containing water via a valve V9 are provided. At this time, the valve 9 may be an automatic valve that keeps the pressure of the supply header 3c constant. A filter may be inserted into the circulation system.

  Further, in order to maintain the concentrations of ozone and additive substances, waste liquid can be discharged from the ozone-containing water tank 3a through the valve V8. Each supply path distributed from the supply header 3c is provided with a flow rate adjusting valve V10 for automatically adjusting the flow rate based on the result of the flow meter G2 that measures the flow rate. The flow rate control valve V10 may be a manual flow rate control valve that finely adjusts the flow rate. In this case, the pressure control by the valve 9 or the stroke control of the pump 3b is performed so that the pressure of the supply header 3c is constant. Alternatively, the number of discharges per unit time may be controlled, or the rotational speed control by an inverter or the like may be performed.

  The additive substance is at least one additive substance selected from the group consisting of a water-soluble organic substance, an inorganic acid, a salt of the inorganic acid, and hydrazine.

  Examples of the water-soluble organic substance include alcohols such as methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol and t-butanol, acetone, acetic acid, formic acid, citric acid and the like.

  Among the above water-soluble organic substances, those having a relatively low boiling point are preferably used from the viewpoint of use as cleaning water for radical water electronic components and the like. For example, n-propanol, iso-propanol, n-butanol, iso- Examples include butanol and t-butanol. The most preferred water-soluble organic substance is iso-propanol (isopropanol).

  Examples of the inorganic acid or the salt of the inorganic acid include hydrochloric acid, sulfuric acid, carbonic acid, carbonate, hydrogen carbonate, nitrous acid, nitrite, sulfite, sulfite, hydrogen sulfite, and hydrofluoric acid. Among these, carbonic acid is preferable because it can be volatilized as carbon dioxide gas after using radical water.

  In the present embodiment, an example in which the generating means 4 that generates radical water is one that adds an ozone decomposition catalyst solution to ozone-containing water in the ozone-containing water supply path 3 will be described. In the present invention, an ozone decomposition catalyst aqueous solution or the like can be used as the ozone decomposition catalyst liquid, and examples of the ozone decomposition catalyst include ammonia, hydrogen peroxide, and other alkaline compounds. When these ozone decomposition catalyst liquids are added to ozone-containing water, ozone is decomposed and OH radicals are generated.

  The generation means 4 includes an ozone decomposition catalyst liquid tank 4a that stores the ozone decomposition catalyst liquid, a pump 4b that supplies the ozone decomposition catalyst liquid, and a filter F3 that filters and removes particles and the like. In this embodiment, the ozone decomposing catalyst solution is constantly circulated through the valve V14, and the ozone decomposing catalyst solution is supplied to the ozone-containing water supply path 3 for supplying each use point through the valve V12 and the supply header 4c. Add.

  On the downstream side of the pump 4b, a valve V13 is provided as a flow rate adjusting valve for automatically adjusting the supply flow rate based on the result of the flow meter G4 that measures the flow rate. The circulation flow rate is kept constant. At this time, the valve 13 may be manually operated, and the pressure of the supply header 4c may be made constant by the pressure adjustment valve V14. Further, each path for supplying to each use point is provided with a valve V11 as a flow rate adjusting valve for automatically adjusting the supplied flow rate based on the result of the flow meter G3 that measures the flow rate. Thus, the ozone decomposition catalyst solution can be added at a predetermined flow rate. The flow rate adjusting valve V11 may be a manual flow rate adjusting valve that finely adjusts the flow rate. In this case, the pressure control by the pressure adjusting valve V14 and the stroke of the pump 4b are performed so that the pressure of the supply header 4c is constant. You may perform control, the frequency | count control of the discharge per unit time, or the rotation speed control by an inverter.

  When a water-soluble organic substance is employed as the additive substance, that is, when an ozone decomposition catalyst such as ozone and hydrogen peroxide and a water-soluble organic substance exist in water, hydroxyl radicals are generated based on the following reaction formula: Conceivable.

  First, hydroxyl radicals are generated from ozone and hydrogen peroxide (Formula 1). Since hydroxyl radicals have a short lifetime, they immediately disappear, but when water-soluble organic substances are present, hydroxyl radicals cause a chain reaction with water-soluble organic substances (Formula 2).

  Furthermore, a hydroxyl radical is generated by the organic radical (R ·) generated by this chain reaction and hydrogen peroxide (Formula 3).

Reaction formula;
Hydroxyl radical generation by reaction of ozone and hydrogen peroxide (Formula 1)
O ₃ + H ₂ O ₂ → OH · + HO ₂ + O ₂
H ₂ O ₂ ⇔ HO ₂ ⁻ + H ⁺
O ₃ + HO ₂ ⁻ → OH · + O ₂ ⁻ · + O ₂
Chain reaction with organic matter (Formula 2)
RH + OH · → R · + H ₂ O
R ・ + O ₂ → RO ₂・
RO ₂・ + RH → ROOH + R ・
RO ₂・ + HO ₂・ → RO ・ + O ₂ + OH ・
Production by decomposition of hydrogen peroxide (Equation 3)
H ₂ O ₂ + R · → HOR + OH ·
On the other hand, when ozone, hydrogen peroxide, and carbonic acid are present in water, it is considered that hydroxyl radicals are generated based on the reaction formula shown below.

  First, hydroxyl radicals are generated from ozone and hydrogen peroxide (Formula 4). Hydroxyl radicals disappear immediately because of their short lifetime, but in the presence of carbonic acid, the hydroxyl radical causes a chain reaction with carbonic acid (Formula 5).

Furthermore, hydroxyl radicals are generated by hydroperxyl radicals (HO _2. ) Generated by the reaction between carbonic acid and hydrogen peroxide and ozone (formula 6).

Reaction formula;
Hydroxyl radical generation by the reaction of ozone and hydrogen peroxide (Formula 4)
O ₃ + H ₂ O ₂ → OH · + HO ₂ + O ₂
H ₂ O ₂ ⇔ HO ₂ ⁻ + H ⁺
O ₃ + HO ₂ ⁻ → OH · + O ₂ ⁻ · + O ₂
Chain reaction with carbonic acid (Formula 5)
CO ₂ + H ₂ O⇔HCO ₃ ⁻ + H ⁺
HCO ₃ ⁻ ⇔ CO ₃ ²⁻ + H ⁺
CO ₃ ²⁻ + OH · → CO ₃ ⁻ · + OH ⁻
CO ₃ ⁻ · + OH · → CO ₂ + HO ₂ ⁻
O ₃ + HO ₂ ⁻ → OH · + O ₂ ⁻ · + O ₂
Hydroxyl radical formation by hydroperxyl radical and ozone generated by the reaction of carbonic acid and hydrogen peroxide (Formula 6)
CO ₂ + H ₂ O⇔HCO ₃ ⁻ + H ⁺
HCO ₃ ⁻ ⇔ CO ₃ ²⁻ + H ⁺
CO ₃ ²⁻ + OH · → CO ₃ ⁻ · + OH ⁻
CO ₃ ⁻ · + H ₂ O ₂ → HCO ₃ ⁻ + HO ₂ ·
^{_{HO 2 · ⇔ + O 2 -}} · + H +
O ₂ ⁻ · + O ₃ → O ₃ ⁻ · + O ₂
O ₃ ⁻ · + H ₂ O → OH · + O ₂ + OH ⁻
In the generation of radical water, the weight ratio of ozone and an ozone decomposition catalyst such as hydrogen peroxide to an additive substance is ozone: ozone decomposition catalyst: additive substance = 10 to 40:10 to 40: 1 to 4. It is preferable to make it dissolve | melt, and it is more preferable to make it dissolve | melt so that it may become ozone: ozone decomposition catalyst: additive substance = 10-20: 10-20: 1-2. By dissolving so that the weight ratio of ozone, the ozone decomposition catalyst and the additive substance is ozone: ozone decomposition catalyst: additive substance = 10-40: 10-40: 1-4, the concentration of hydroxyl radicals is higher. Because it can be.

  The pipe length varying means 6 has a structure that can substantially change the pipe length of the radical water supply path 5. As shown in FIG. 4, the pipe length varying means 6 preferably has a valve mechanism V20 that can change the mixing position for adding the ozone decomposition catalyst liquid to the radical water.

  In this pipe length varying means 6, a plurality of U-shaped pipes P1 are connected to a valve header 6a having a valve mechanism V20 made up of a plurality of on-off valves, and all U-shaped pipes P1 are connected via the respective on-off valves. Are connected, and another port of any on-off valve is opened so that the ozone decomposition catalyst solution can be added and mixed at that position. At this time, the ozone decomposition catalyst liquid flows through the valve header 6a and is added to the ozone-containing water supply path 3 via the open / close valve in the valve header 6a. As a result, radical water is generated, and the downstream path from the addition position becomes the radical water supply path 5. And it becomes possible to change the length of the supply path 5 of radical water depending on which one of the on-off valves is opened.

  In this embodiment, in order to supply radical water to a plurality of use points, the same number of pipe length variable means 6 is provided. Each supply path 5 is provided with a mixer M2 for stirring the radical water and a filter F4 for filtering out impurities and the like.

  According to the study by the present inventors, the reaction of dissolved ozone and the ozonolysis catalyst solution instantaneously reaches a maximum value if the complete mixing can be performed instantaneously. As shown in FIG. 2, it was found that the maximum radical concentration was delayed by several seconds from the time when the ozone decomposition catalyst solution was mixed. In addition, since the reaction rate and mixing state with dissolved ozone differ depending on the concentration of the ozone decomposition catalyst to be mixed, the time from the point of injection of the ozone decomposition catalyst solution to the maximum radical concentration is the concentration of the ozone decomposition catalyst to be injected. It depends on.

  Therefore, for example, as shown in FIG. 2, when the concentration of the ozone decomposition catalyst is high, the pipe length is variable so that the radical water is supplied to the use point after time t1 from the injection of the ozone decomposition catalyst liquid. If the piping length of the radical water supply path 5 is substantially changed by the means 6, supply at the maximum radical concentration is possible. Similarly, if the pipe length of the supply path 5 is substantially changed by the pipe length variable means 6 so that the radical water is supplied to the use point at times t2, t3, and t4 according to the concentration of the ozone decomposition catalyst, Supply at the maximum radical concentration is possible at any concentration of the ozonolysis catalyst.

  In the present invention, it is preferable to provide concentration measuring means 7 for measuring the concentration of hydroxyl radical-containing water in the radical water supply channel 5. The concentration measuring means 7 is a means for measuring the concentration of hydroxyl radical-containing water in the radical water supply channel 5. In the present invention, the concentration measuring means 7 is preferably one that optically detects the concentration with respect to hydroxyl radicals. By detecting the density optically, the density can be measured and the density can be controlled with higher responsiveness in-line.

  The concentration measuring means 7 is, for example, a measuring means for measuring the light absorption characteristics in the wavelength region including the wavelength of 195 to 400 nm of the sample, and the absorbance measured based on the extinction coefficient of hydroxyl radical in the wavelength region including the wavelength of 195 to 400 nm. And calculating means for determining the concentration of hydroxyl radicals from the characteristics.

  The measurement means includes, for example, a light source that generates probe light, a cell 7a that irradiates the probe light, a spectroscope that splits the probe light emitted from the cell 7a, and a detector that detects the intensity of the spectroscopically separated specific wavelength light. It has.

  The calculation means includes, for example, a digital oscilloscope connected to the detector and a personal computer (PC) connected to the digital oscilloscope. Also, a delay time generator may be provided, and a timing control signal for controlling the time interval with the capture time gate integrated by the integrator may be sent to the digital oscilloscope.

  The extinction coefficient of the hydroxyl radical can be determined as follows, although literature values can be used. For example, after irradiating an aqueous solution containing ozone with excitation light and measuring a change in light absorption characteristics immediately after irradiation in a wavelength region including wavelengths of 195 to 205 nm, initial values of known absorption coefficients such as ozone and hydrogen peroxide are used. After obtaining an optimum solution of the extinction coefficient and concentration-time profile assuming two components, the initial value of the extinction coefficient of the third component is calculated from the difference between the absorbance profile calculated from the optimum solution and the actually measured absorbance profile. It is preferable to obtain the extinction coefficient of the accelerated oxidation active species by obtaining the value and obtaining the optimum solution of the extinction coefficient and the concentration-time profile assuming three components.

  In order to obtain the hydroxyl radical concentration from the measured light absorption characteristics based on the extinction coefficient of such hydroxyl radical, the concentration can be obtained from the absorbance, the molar extinction coefficient, and the optical path length of the cell based on the Lambert-Beer rule. Is possible. Further, by the multicomponent simultaneous quantification method, it is possible to obtain the concentration of the accelerated oxidation active species from the absorbance at a plurality of wavelengths, the molar extinction coefficient of each component at a plurality of wavelengths, and the optical path length of the cell. For this reason, the light absorption characteristics can be measured in-line, and the concentration of the accelerated oxidation active species as the calculation result can be displayed on the screen or output data in real time.

  In this invention, it is preferable to provide the control means 8 which adjusts the production | generation means 4 based on the density | concentration of the hydroxyl radical containing water measured by the density | concentration measurement means 7, so that the density | concentration may approach a setting value. In this embodiment, by sending a signal for changing the set value of the flow rate from the control means 8 to the valve V11 for automatically adjusting the flow rate of the ozone decomposition catalyst liquid supplied via the supply header 4c, The generation means 4 is adjusted.

  For example, when the concentration of hydroxyl radical-containing water measured by the concentration measuring means 7 is lower than the set value, the control means 8 sends a signal for increasing the set value of the flow rate to the valve V11. It is possible to bring the density to be close to the set value. For such control, known proportional control, integral control, differential control, and a combination of these (PID control) can be employed.

  Further, the pipe length variable means 6 can be operated by the control means 8 so as to approach the concentration according to the concentration of hydroxyl radicals required at the use point. For example, since the required concentration of hydroxyl radicals is high, when the concentration of the ozonolysis catalyst solution is high, the supply path for the radical water is supplied by the pipe length variable means 6 so that the radical water is supplied to the use point at time t1. If the pipe length of 5 is substantially changed, supply at the maximum radical concentration becomes possible. Similarly, the pipe length of the supply path 5 can be substantially changed by the pipe length varying means 6 so that the radical water is supplied to the use point at times t2, t3, and t4 according to the required concentration of hydroxyl radical. For example, supply at the maximum radical concentration is possible at any required concentration of hydroxyl radicals.

  Meanwhile, the hydroxyl radical-containing water supply method of the present invention adds ozone decomposition catalyst liquid to the ozone-containing water while supplying ozone-containing water in which ozone and an additive that suppresses decomposition of ozone are dissolved in pure water. In the radical water supply method in which radical water is generated by the generating means 4 and the generated radical water is transferred to the use point and supplied, the pipe length of the supply path 5 can be changed substantially. The radical water is supplied through the means 6.

  As described above, the hydroxyl radical-containing water supply method of the present invention can be preferably carried out by the apparatus of the present invention. A preferred embodiment of the hydroxyl radical-containing water supply method of the present invention is as described for the apparatus of the present invention.

  When radical water is used as the cleaning liquid, the object to be cleaned from which organic substances can be removed is not particularly limited. For example, the surface of a semiconductor wafer, device, liquid crystal substrate, or the like needs to be strictly cleaned. It is preferably a precision part. This is because radical water can effectively remove organic substances without affecting the environment, the human body, or the object to be cleaned. Specific examples of precision components include electronic components such as silicon wafers, printed substrates, glass substrates, liquid crystal substrates, magnetic disk substrates, compound semiconductor substrates, and the like; and various components in such electronic component manufacturing apparatuses and cleaning apparatuses, such as , Filter for filtration, filter housing for filtration, piping, wafer carrier, washing tank, pump and the like.

  Although the details of the mechanism by which the removal effect of the organic substance is obtained by the radical water are not clear, it is considered that the removal effect of the organic substance is exhibited based on the following action and mechanism. Hydroxyl radicals have a strong oxidizing and bactericidal action. For this reason, the hydroxyl radical neutralizes the charge of the organic substance, so that the neutralized organic substance is released from the surface of the object to be cleaned, and acts to make it difficult to reattach. For example, in the case of an organic substance, water and carbon dioxide are obtained by oxidative decomposition, and in the case of a metal, electrons are taken from the metal, ionized, and dissolved in the cleaning liquid.

  When radical water is used as the cleaning liquid, the method of applying the radical water to the object to be cleaned is not particularly limited. For example, an immersion method in which the object to be cleaned is immersed in the radical water may be used. A spraying method may be used in which radical water is sprayed onto the washed product by a shower.

  The contact time between the radical water and the object to be cleaned cannot be generally defined, and may be set as appropriate according to the degree of contamination of the object to be cleaned, the application method of the radical water, the required degree of cleaning, and the like.

(Other embodiments)
(1) In the above-described embodiment, the example in which the pipe length variable means is operated in advance according to the concentration of hydroxyl radical or the concentration of the ozonolysis catalyst solution has been shown. However, in the present invention, the concentration measuring means is controlled by the control means. Based on the concentration of hydroxyl radical-containing water measured in step (1), it is also possible to perform control for operating the pipe length variable means.

  When the concentration of hydroxyl radicals decreases at the measurement point p1 shown in FIG. 2, if it is attempted to supply the radical water having the maximum radical concentration at the use point, it is necessary to increase the time until the supply. In this embodiment, in such a case, based on the radical water concentration measured by the concentration measuring means 7, the pipe length of the radical water supply path 5 is substantially increased by the pipe length varying means 6. By doing so, radical water with the maximum radical concentration can be supplied at the point of use.

  Moreover, it is also possible to perform control for operating the pipe length variable means 6 by the control means 8 based on the concentration of the ozone decomposition catalyst or the amount of addition of the ozone decomposition catalyst liquid when adding the ozone decomposition catalyst liquid to the ozone-containing water. It is. For example, in the case of the apparatus shown in FIG. 3, the pipe length variable means 6 can be operated by the control means 8 based on the measurement result of the flow meter G3.

  (2) In the above-described embodiment, the example using the pipe length varying means 6 shown in FIG. 4 is shown. However, in the present invention, the pipe length of the supply path for hydroxyl radical-containing water can be substantially changed. For example, the pipe length varying means having any structure can be used.

  For example, as shown in FIG. 5, the ozone-containing water supply path 3, the radical water supply path 5, and the ozone-decomposing catalyst liquid supply path are connected, and the flow path groove for flowing the ozone-decomposing catalyst liquid and the ozone-containing water And a tubular member 6b having a plurality of openings formed in a surrounding spiral position, which is inserted in a watertight manner in the central flow path of the valve header 6a. Is mentioned.

  By rotating the tubular member 6b using a rotary actuator or the like while flowing ozone-containing water inside the tubular member 6b, the position of the opening that opens to the flow channel groove changes in the longitudinal direction of the tubular member 6b. Therefore, the position where the ozone decomposition catalyst solution is added and mixed can be changed, and the piping length of the radical water supply path 5 can be substantially changed.

  As the other pipe length variable means 6, it is possible to adopt means that does not change the position where the ozone decomposition catalyst solution is added and mixed. For example, the pipe length variable means 6 includes a bellows-like flexible pipe and an actuator that changes its length. And a pipe provided with an inner pipe inserted into the outer pipe in a watertight manner and capable of expanding and contracting and an actuator for changing its length.

  Such a pipe length varying means 6 can be provided at any position of the radical water supply path 5. For example, such a pipe length variable means 6 can be provided downstream of the hydroxyl radical concentration measuring means.

  (3) In the above-described embodiment, an example is shown in which the control unit controls the hydroxyl radical-containing water generation unit and the pipe length variable unit. However, the control unit further controls the ozone water generation unit or the additive substance mixing unit. It is also possible to do.

  (4) In the above-described embodiment, the example using the concentration measuring means for obtaining the concentration of the hydroxyl radical from the measured absorption characteristic based on the extinction coefficient of the hydroxyl radical in the wavelength region including the specific wavelength is shown. By measuring the absorption of far-ultraviolet light at the bottom part (for example, 170 to 210 nm) of the absorption peak of the absorption peak of water (n → σ * transition absorption band of water molecule) appearing in the ultraviolet region, the hydroxyl radical It is also possible to use a concentration measuring means for measuring the concentration of the above.

  The hydroxyl radical-containing water production apparatus and production method of the present invention can be used in many processes in the production of semiconductors and displays, and in general manufacturing industries. For example, a resist removal process on a glass substrate such as a mask for a semiconductor, various resist removal processes in an FPD process, various resist removals in a transistor process in a previous process of a silicon semiconductor substrate, organic substance contamination removal, and a wiring process in the subsequent process Can be used in various resist removal steps, organic matter contamination removal, other organic matter removal steps on other substrates, other organic matter removal steps, hydrophilization steps of various substrates, other hydrophilization steps, and the like. Further, it can be used in fields such as sterilization washing of food and decomposition treatment of environmental pollutants.

DESCRIPTION OF SYMBOLS 1 Ozone water production | generation means 2 Additive substance mixing means 3 Ozone containing water supply path 4 Hydroxyl radical containing water production means 5 Hydroxyl radical containing water supply path 6 Pipe length variable means 7 Hydroxyl radical containing water concentration measuring means 8 Control means

Claims (8)

An ozone-containing water supply path for supplying ozone-containing water in which ozone and an additive that suppresses decomposition of ozone are dissolved in pure water;
A generating means provided in the supply path for adding an ozone decomposition catalyst solution to the ozone-containing water to generate hydroxyl radical-containing water;
In a hydroxyl radical-containing water supply device comprising: a hydroxyl radical-containing water supply path that transports and supplies the generated hydroxyl radical-containing water to a use point;
A hydroxyl radical-containing water supply device comprising a pipe length variable means capable of substantially changing the pipe length of the hydroxyl radical-containing water supply path. A concentration measuring means provided in the supply path for the hydroxyl radical-containing water and measuring the concentration of the hydroxyl radical-containing water;
2. The hydroxyl radical-containing water supply device according to claim 1, further comprising a control unit that adjusts the generation unit based on the concentration of the hydroxyl radical-containing water measured by the concentration measuring unit so that the concentration approaches a set value. .   The control means operates the pipe length varying means and the generating means based on the concentration of hydroxyl radical-containing water necessary for treatment and the concentration of hydroxyl radical-containing water measured by the concentration measuring means. The hydroxyl radical containing water supply apparatus of description.   The hydroxyl radical-containing water supply device according to any one of claims 1 to 3, wherein the pipe length varying means has a valve mechanism capable of changing a mixing position at which an ozone decomposition catalyst solution is added to the hydroxyl radical-containing water. While supplying ozone-containing water in which ozone and an additive that suppresses decomposition of ozone are dissolved in pure water, while generating hydroxyl radical-containing water by the generating means for adding the ozone-decomposing catalyst solution to the ozone-containing water In the method for supplying hydroxyl radical-containing water, the generated hydroxyl radical-containing water is transferred to the use point and supplied.
A hydroxyl radical-containing water supply method, wherein the hydroxyl radical-containing water is supplied through a pipe length variable means capable of substantially changing the pipe length of the supply path.   The concentration measuring means measures the concentration of the hydroxyl radical-containing water and adjusts the generating means based on the concentration of the hydroxyl radical-containing water measured by the concentration measuring means so that the concentration approaches a set value. The method for supplying hydroxyl radical-containing water according to claim 5, wherein control is performed.   The concentration measuring means measures the concentration of the hydroxyl radical-containing water, and the pipe length variable means is based on the concentration of the hydroxyl radical-containing water necessary for the treatment and the concentration of the hydroxyl radical-containing water measured by the concentration measuring means. And a method for supplying water containing hydroxyl radicals according to claim 6.   The said piping length variable means is a hydroxyl radical containing water supply method in any one of Claims 5-7 which has a valve mechanism which can change the mixing position which adds an ozonolysis catalyst liquid to the said hydroxyl radical containing water.

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