JP2581403B2 - Wet processing method and processing apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wet processing method and a processing apparatus used in a material processing process for industrial products, pharmaceutical products and the like.

[0002]

2. Description of the Related Art In recent years, global environmental problems have attracted interest in various fields as new environmental problems. 2. Description of the Related Art Modern industries have become active, and industrial wastes, medical wastes, industrial wastewaters, and the like have been released into the global environment, causing environmental problems on a global scale. Especially in the process of manufacturing industrial and pharmaceutical products,
In the case of cleaning, etching, and post-processing, the processing has been performed using a solution containing halogen or chlorofluorocarbon, an acidic solution or an alkaline solution such as hydrochloric acid, or a gas containing halogen or chlorofluorocarbon. On the other hand, city water is electrolyzed and Na and Ca
Devices that generate high-concentration alkaline ionized water and use it as health drinking water, and that use acidic ionized water as beauty and face wash have been commercially available since ancient times.

[0003]

Conventionally, a treatment is performed using a solution containing halogen or chlorofluorocarbon such as chlorine, an acid solution or an alkaline solution such as hydrochloric acid, or a gas containing halogen or chlorofluorocarbon which has been used in a cleaning process or the like. In such a case, a halogen compound or a chlorofluorocarbon compound is formed, thereby producing industrial waste which is difficult to treat. The present invention has been made in order to solve such conventional problems, and a wet processing method and a processing apparatus and a wet processing method used for cleaning, etching or post-processing without causing contamination by difficult-to-treat industrial waste. An object of the present invention is to provide an electrolytic water generation method used in a wet treatment method.

[0004]

The present invention SUMMARY OF], the new H ⁺ ionized water or OH is produced by electrolysis of water ^- by supplying to the ion-water always object to be processed,
A wet treatment method for cleaning, etching, or post-treating an object to be treated, wherein electrolysis of water is carried out at the start of electrolysis or during electrolysis at a wavelength of 0.4 μm or less or X-rays.
This is a wet treatment method, wherein the treatment is performed while irradiating water or an aqueous solution with a line or a long wavelength light or an electromagnetic wave of 3 μm or more.

[0005] Further, a processing apparatus for carrying out this method includes an inlet pipe for supplying water to an electrolysis water tank, and an H pipe inside.
⁺ Ionized water and OH ^- and the porous membrane is provided to separate the ionized water, through the electrolysis of electrolysis tanks the water introduced from the inlet pipe, the porous membrane in electrical cracking water tank an electrode pair provided Te, a DC power source for supplying a direct current to the electrode pairs, the H ⁺ ion water obtained by electrolysis tanks and OH ^- ion water as well as reservoir respectively separately, in which A treatment water tank for treating an object to be treated, and a light source for irradiating the electrolysis water tank with light, X-rays, or electromagnetic waves,
Measuring the pH value and the oxidation-reduction potential in the treated water tank,
A comprehensive control system for controlling the ion concentration and the oxidation-reduction potential in the treated water tank by adjusting the intensity of the electrolytic current of the DC power supply and / or the light irradiation amount or light intensity of the light source is provided. .

Further, according to the present invention, short-wavelength light of 0.4 μm or less or X
A method for producing electrolyzed water is provided, wherein water is electrolyzed while irradiating water or an aqueous solution with a line or a long wavelength light or an electromagnetic wave of 3 μm or more.

[0007]

The treatment method of the present invention can be applied to industrial products and pharmaceutical products without using a conventionally used solution containing halogen or chlorofluorocarbon, an acidic solution or an alkaline solution, or a gas containing halogen or chlorofluorocarbon. Processing can be performed. According to this processing method, heavy metal contaminants on a silicon wafer used in a semiconductor manufacturing process are removed by always performing processing with newly supplied H ⁺ ion water. This is because, since the heavy metals OH groups in alkaline wash water tends to complex ion with a ligand, easily adsorbed on the wafer surface, the H ⁺ ion water does not form such a complex ions and heavy metals, the wafer This is because it is difficult to be adsorbed on the surface.

Further, in the present treatment method, the pH value of the generated water can be controlled by adjusting the direct current at the time of electrolysis or by adjusting the amount of a substance which enhances the electrolysis efficiency described later. . In this case, according to the Purvey diagram, the metallic material has a certain range of pH.
(For example, Fe: pH 3 to 10), the metal material is dissolved (etched) when the pH is higher or lower. Therefore, in the process of manufacturing industrial products and pharmaceutical products, when removing residual halogens such as residual chlorine, treatment with H ⁺ ionized water at a pH within a specified range may damage metal material parts. The residue can be removed without the need. For example, in the microfabrication of an aluminum alloy film in a semiconductor manufacturing process, etching is performed using chlorine-based gas plasma. After etching, residual chlorine is removed in the form of HC1 using H ⁺ ionized water, and then activated. the aluminum surface is OH ^-
Treatment with ionized water can stabilize the aluminum surface. This processing method has a greater corrosion prevention effect and less damage to the processed aluminum film and the base film than the conventionally used wet processing using pure water. In addition, since convection occurs directly on the aluminum surface as compared with the gas ashing process, the effect of removing chlorine remaining on the side surface and the surface of the wiring film is large. When a metal material is treated at a pH exceeding a specified range, it can be used as an etching solution. For example, conventionally, wet etching of a metal material with HC1, phosphoric acid, or the like has been performed, but it can be used as a solution instead of these.

In addition, in the electrolysis of water, the electrolysis is performed in a state in which a substance for increasing the electrolysis efficiency is added, so that the resistance value of pure water is reduced and the generation efficiency is improved. In a process such as a semiconductor manufacturing process in which contamination by heavy metals becomes a problem, carbon dioxide or a supporting electrolyte salt (a combination of a quaternary alkylammonium and an anion other than halogen) is suitable as the substance for improving the electrolysis efficiency. In selecting a supporting electrolytic salt, when removing metal contamination such as Fe which is easily taken into the natural oxide film, ammonium fluoride is used as an electrolytic salt to remove Fe together with the natural oxide film. It is preferable to use ammonium acetate when it is desired not to damage the surface oxide film and the metal part, and to use ammonium chloride when the metal part is not particularly concerned. When ionic water is generated by electrolysis of pure water, it is preferable to apply high electrolytic strength between the anode and the cathode in order to improve the efficiency of electrolysis. The electrolytic strength at this time is 10 ³ to 10 ⁴ V / c.
About m is appropriate.

In order to more efficiently generate ionic water used for cleaning and etching, short-wavelength light or X-rays of 0.4 μm or less at the start of or during electrolysis,
Alternatively, water is electrolyzed while irradiating water or an aqueous solution with long-wavelength light or an electromagnetic wave of 3 μm or more. First, by irradiating light having a short wavelength of 0.4 μm or less during electrolysis, electrolysis of water is promoted. An example of the principle of water electrolysis is shown. For example, in the case of decomposing a 0.1N NaOH solution, the energy position of the oxygen generation level is 0.16 e from the standard saturated sweet electrode potential (SEC).
V below, and the hydrogen generation level is above 1.07 eV. Therefore, theoretically 1.23 eV (1.
07 eV + 0.16 eV) or more. Actually, instead of using the above solution, use a solution with a lower concentration or pure water, and consider the overvoltage necessary to apply current to both electrodes, and apply a considerably higher voltage between both electrodes. Must be applied. If this energy level difference is assisted by irradiating high energy light (short wavelength light), the electrolysis efficiency will be improved. In addition, efficient electrolysis can be performed by irradiating the electrolytic cell with short-wavelength light having high energy for a period of time from the start of electrolysis until the steady electrolytic current is reached. FIG. 2 is a view showing this fact, in which ultraviolet rays (6 eV) are used.
When irradiation is performed and when irradiation is not performed.
Voltage applied between the electrodes (1-A) and (1-B) of the electrolytic cell.
The figure shows the relationship between pressure and electrolytic current.
If this occurs, the electrolysis efficiency will increase and the electrolytic current will increase.
I understand. On the other hand, by irradiating long-wavelength light with far-infrared light of 3 μm or more or high-frequency waves such as microwaves, water clusters can be separated and ionization efficiency can be improved. FIG. 3 is a diagram showing this, and the microwave
(2.45 GHz) and non-irradiation
Electrodes (1-A) and (1-
The relationship between the voltage applied during B) and the electrolytic current is shown. Same figure
From microwave irradiation, the electrolysis efficiency is improved
It can be seen that the electrolytic current increases. According to the method,
Addition of pure water or a substance that enhances the electrolysis efficiency to a lesser extent can produce ionized electrolyzed water efficiently, and can provide electrolyzed water having a high pH and a high oxidation-reduction potential even in a flowing water system.

According to the present invention, conventionally used solutions containing halogen and chlorofluorocarbon, acidic solutions and alkaline solutions,
Or without using a gas containing halogen or Freon,
Material processing of industrial products and pharmaceutical products can be performed. For example, conventionally, an aqueous solution of HCl (HCl, H ₂ O ₂ , H ₂ O
In a mixed solution of HCl (30
%): H ₂ O ₂ (30%): H ₂ O = 1: 1: 3 to 10
Used in Therefore, if the HCl concentration is between 2% and 8%,
It becomes a thick solution. Commonly used for cleaning semiconductors
Cleaning solution. ) , Ammonia peroxide ( NH ₄ O)
It is a mixed solution of H, H ₂ O ₂ and H ₂ O.
NH ₄ OH (29%): H ₂ O ₂ (30%): H ₂
O 2 = 1: 1 to 8: 4 to 100 are used. Therefore, N
H ₄ OH concentration becomes about 0.3% to 5% solution
It is a washing solution commonly used for body washing. )
Wet treatments such as heavy metal contamination removal and particle removal have been performed with sulfuric acid or phosphoric acid, but can be used as a solution instead of these. Further, according to the present invention, the used waste liquid is converted into pure water through a water purifier and an ion exchanger, and can be reused to effectively use water resources.

[0012]

Next, an embodiment of the present invention will be described. Embodiment 1 FIG. 1 shows a schematic configuration diagram of a wet processing apparatus of the present embodiment. Pure water generated through the ion exchanger 9 is supplied to the electrolysis water tank 1 of FIG. 1 from a pure water introduction pipe. In the electrolysis water tank 1, a porous film 2 of polysilicon or the like is formed as a diaphragm, and the water tanks (1-A) and (1-
B) includes electrode rods 3a and 3b made of Pt or carbon.
Is installed. By connecting a variable DC power supply 5 to the electrode rods 3a and 3b and flowing an electrolytic current, a cathode water (OH ⁻ ) is supplied to the water tank (1-A) having the electrode 3a serving as a cathode.
(Ionized water), a water tank (1-B) having an electrode 3b serving as an anode
Produces anode water (H ⁺ ion water). The resulting OH ^-
Ion water is placed in the treatment tank 6a, and H ⁺ ion water is placed in the treatment tank 6a.
b. An Si wafer, which is a typical object to be processed in a semiconductor manufacturing process, is placed in a wafer carrier 7a or 7b and immersed in the processing water tank 6a or 6b. In this case, the electrolyzed water (ionized water) takes a flowing water form that is always supplied to the Si wafer. The waste liquid from the treated water tank 6a or the treated water tank 6b is stored in a waste liquid storage tank 8, and the supernatant is purified into pure water through a water purifier 10 and an ion exchanger 9. Reuse.

Here, each of the water tanks (1-A, 1-B) of the electrolysis water tank 1 is irradiated with light from the light source 13. This light source 13 has a wavelength of 0.4 μm as a short wavelength oscillation light source.
An ultraviolet light source capable of irradiating the following light, an X-ray source or a γ-ray source capable of irradiating a wavelength of 0.1 μm or less is used. As a light source of long-wavelength light, a far-infrared light source that oscillates light of 3 μm or more or a microwave source that oscillates light of 1000 μm or more is used. Quartz or the like is used for the material of the water tank 1 so that the light reaches the electrode rods 3a and 3b effectively. When cleaning the Si wafer, the treatment water tank 6a OH ^- water or process water tank 6
b of H ⁺ water only treated it may be subjected to, also, OH ^- be subjected to H ⁺ water treatment after water treatment, after the H ⁺ water treatment OH ^- may be subjected to a water treatment. Also, in order to lower the resistance value of pure water supplied from the ion exchanger and increase the electrolysis efficiency,
A conductive substance addition system 11 for bubbling and supplying carbon dioxide or adding a supporting electrolyte salt such as ammonium acetate to pure water is provided. Further, the H ⁺ concentration and the OH ^- concentration are detected by the pH sensors 4a and 4b installed in the treatment water tanks 6a and 6b, and the reduction potential and the oxidation potential are measured by the reduction potential sensor 14 and the oxidation potential sensor 15, respectively. The result is transmitted to the DC power supply 5 through the comprehensive control system 16.
Feedback is applied to the electric field current intensity of the above, the amount of the conductive substance added from the conductive substance addition system 11, and the irradiation amount or intensity of the light source 13.

[0014]

[Effect of the Invention] In the process of manufacturing industrial products and pharmaceutical products, when cleaning, etching, and post-processing are performed,
Halogen, chlorofluorocarbon or its compound, or contamination due to difficult-to-treat industrial waste is caused. According to the present invention, treatment can be performed without causing environmental pollution as described above. Also, when a substance that enhances electrolysis efficiency is added to pure water, it can serve as a small amount of acid and alkali solutions that have been conventionally used, greatly reducing process costs and reducing the amount of waste. Can be drastically reduced. Therefore, it is possible to drastically reduce industrial waste, medical waste, industrial wastewater, and the like, which are released to the global environment and are a source of environmental problems caused on a global scale. Further, by reusing the treatment waste liquid as pure water, water resources can be effectively used. Further, according to the method for producing electrolyzed water according to the present invention, a large amount of electrolyzed water having a higher pH and oxidation-reduction potential can be efficiently produced in a flowing water type electrolytic cell, and can be used for cleaning and etching.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a wet processing apparatus according to the present invention.

FIG. 2 is a diagram showing a relationship between an electrode applied voltage and an electrolytic current when irradiating ultraviolet rays, in comparison with a case where no ultraviolet rays are irradiated.

FIG. 3 is a diagram illustrating a relationship between an electrode applied voltage and an electrolytic current when a microwave is irradiated, in comparison with a case where a microwave is not irradiated.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Electrolysis water tank 1-A Cathode water (OH ^- ion water) water tank 1-B Anode water (H ⁺ ion water) water tank 2 Porous membrane (diaphragm) 3a Electrode rod (cathode) 3b Electrode rod (anode) 4a 4b pH sensor 5 DC power supply 6a, 6b Treatment water tank 7a, 7b Wafer carrier 8 Waste liquid storage tank 9 Ion exchanger 10 Water purifier 11 Conductive substance addition system 13 Light source 14 Reduction potential sensor 15 Oxidation potential sensor 16 General control system

Claims (2)

(57) [Claims] 1. A wet process for washing, etching or post-processing an object by constantly supplying new H ⁺ ion water or OH ⁻ ion water generated by electrolyzing water to the object. The method, wherein the electrolysis of water is carried out at the beginning of or during electrolysis.
A wet treatment method, wherein the treatment is performed while irradiating water or an aqueous solution with short-wavelength light or X-rays of 3 μm or less, or long-wavelength light or electromagnetic waves of 3 μm or more on water or an aqueous solution. 2. An introduction pipe for supplying water to an electrolysis water tank, and a porous membrane for separating H ⁺ ion water and OH ⁻ ion water are provided therein, and the water introduced from the introduction pipe is used for electricity. An electrolysis water tank to be decomposed, an electrode pair provided in the electrolysis water tank via the porous membrane, a DC power supply for supplying a DC current to the electrode pair, and the electrolysis water tank. H ⁺ ion water and OH ⁻ ion water are separately stored, and a treatment water tank for treating an object to be treated therein, a light source for irradiating the electrolysis water tank with light, X-rays or electromagnetic waves, By measuring the pH value and the oxidation-reduction potential in the treatment water tank, and adjusting the electrolytic current intensity of the DC power supply and / or the light irradiation amount or light intensity of the light source,
A wet treatment apparatus comprising an integrated control system for controlling ion concentration and oxidation-reduction potential in a treatment water tank.