JP2005313174A - Treatment method using dielectric barrier discharge lamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a treatment method using a dielectric barrier discharge lamp by which various treatments are carried out in a high grade at a high speed with high efficiency. <P>SOLUTION: A material to be treated are brought into contact with a treating fluid containing at least oxygen and is treated by a 1st dielectric barrier lamp and a 2nd dielectric barrier lamp which emit ultraviolet rays each having a different wave length and ozone is produced by the irradiation with the ultraviolet ray from the 1st dielectric barrier discharge lamp and active oxygen is produced by the irradiation with the ultraviolet ray from the 2nd dielectric barrier discharge lamp. Decomposition and activation are carried out by the irradiation of ultraviolet ray emitted from the 1st dielectric barrier discharge lamp and reactivation is carried out by the irradiation of ultraviolet ray emitted from the 2nd dielectric barrier discharge lamp to treat the material to be treated by bringing the material into contact with the treating fluid. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a treatment method using a dielectric barrier discharge lamp as a light source for photochemical reaction, for example, treatment of chlorofluorocarbon gas or various waste gases, treatment of clean water, sewage, various factory waste waters, washing, or The present invention relates to improvement of a method for treating various objects to be processed, such as a film forming method for producing a hydrogenated amorphous silicon thin film or the like used for a solar cell or the like.

  As a technique related to the present invention, for example, Japanese Patent Publication No. Hei 3-212183 discloses a dielectric barrier discharge (also known as an ozonizer discharge. Revised edition “Discharge Handbook” published by the Institute of Electrical Engineers of Japan, reprinted in June 1999, 7th edition. Describes an apparatus for producing a thin film by a CVD method using ultraviolet rays radiated from a lamp. Japanese Laid-Open Patent Publication No. 3-122287 describes a method for metallizing a substrate using ultraviolet rays emitted from a lamp using dielectric barrier discharge. The processing method using the dielectric barrier discharge lamp as described above has various features that the dielectric barrier discharge lamp does not have in the conventional low-pressure mercury discharge lamp and the high-pressure arc discharge lamp. It is useful because it is obtained. For example, a thin film manufacturing method using a dielectric barrier discharge lamp is useful because a thin film for solar cells and various semiconductor elements can be manufactured with high quality.

  The conventional processing method described above employs a method of irradiating the processing fluid or the object to be processed or the both with one kind of ultraviolet light only once. For example, in a thin film manufacturing method using a dielectric barrier discharge lamp, a plurality of process gases as processing fluids and a substrate as an object to be processed are accommodated in one reaction chamber, and one type of dielectric barrier discharge is performed. A film was formed on the substrate by a method of decomposing and activating the process gas by irradiating the process gas with one type of ultraviolet light emitted from the lamp only once. At this time, the substrate is also irradiated with ultraviolet rays that have not been absorbed by the process gas. In the above-described conventional processing method, even if the ultraviolet irradiation is repeated twice or more, the type of chemical reaction generated on the process gas and the substrate is the same as that when the first ultraviolet irradiation is performed. This only corresponds to extending the ultraviolet irradiation time.

  In general, the optimum conditions for activating, decomposing, ionizing or synthesizing a certain substance by photochemical reaction, that is, the wavelength and intensity of ultraviolet rays to be irradiated, the temperature of the substance, and the like vary depending on the kind of the substance. Therefore, in a method of processing a workpiece by bringing the workpiece into contact with a processing fluid, at least one of the workpiece or the processing fluid is irradiated with one type of ultraviolet light from a dielectric barrier discharge lamp only once. The method of processing by irradiation has a problem that the processing is incomplete, or the processing speed or processing efficiency is not always sufficient.

  An object of the present invention is to provide a treatment method using a dielectric barrier discharge lamp that can perform various treatments with high quality and can be performed at high speed or with high efficiency.

  The object of the present invention is to provide a dielectric barrier for processing an object to be processed and a processing fluid in contact with each other by a first dielectric barrier discharge lamp and a second dielectric barrier discharge lamp that emit ultraviolet rays having different wavelengths. This is achieved by a processing method using a discharge lamp.

  That is, in a wet cleaning method in which an object to be processed is immersed in water to clean the outer surface of the object to be processed, a first dielectric barrier discharge lamp and a second dielectric barrier discharge lamp that emit ultraviolet rays having different wavelengths. Thus, a processing method using a dielectric barrier discharge lamp for processing the object to be processed and the processing fluid in contact with each other, wherein the processing fluid is a fluid containing oxygen, and the processing fluid includes the first fluid. The ozone is generated by irradiating the ultraviolet light from the dielectric barrier discharge lamp of this, and the active oxygen is generated by irradiating the ultraviolet light from the second dielectric barrier discharge lamp, and the processing fluid is mixed into the water. And this is achieved by processing the object to be processed.

  When a dielectric barrier discharge lamp is used as an ultraviolet light source when using at least a photochemical reaction due to ultraviolet rays and processing the workpiece by bringing the workpiece into contact with a processing fluid, a conventional low-pressure mercury discharge lamp or Compared to high-pressure arc discharge lamps, dielectric barrier discharge lamps can generate specific ultraviolet rays with high efficiency, are almost monochromatic light, have low lamp temperature, and have a high degree of freedom in shape. High-efficiency and high-speed processing is possible with a small device. According to the present invention, since the first dielectric barrier discharge lamp and the second dielectric barrier discharge lamp that emit ultraviolet rays having different wavelengths are used, the first ultraviolet irradiation and the second ultraviolet irradiation. Therefore, activation, decomposition, ionization, and synthesis are optimally performed. As a result, high-efficiency and high-speed processing can be performed with a small apparatus.

  According to the present invention, since the first dielectric barrier discharge lamp and the second dielectric barrier discharge lamp that radiate ultraviolet rays having different wavelengths are used, various processes are performed with high quality, high efficiency, and sufficient speed. It is possible to provide a processing method that can be performed in

  A schematic diagram of a water treatment method according to the first embodiment of the present invention is shown in FIG. The box-shaped reaction vessel 5 has substantially two reaction space regions by two dielectric barrier discharge lamps 6 and 7 on a flat plate having a structure for emitting ultraviolet rays on both sides. A schematic diagram of a dielectric barrier discharge lamp is shown in FIG. A discharge space 23 is formed by dielectrics 20 and 21 and a side plate 22 on a flat plate that transmits ultraviolet rays, and the discharge space 23 is filled with a luminescent gas. When a voltage is applied to the transparent electrodes 24 and 25 made of a metal net provided on the surfaces of the dielectrics 20 and 21 by the AC power source 26, a so-called dielectric barrier discharge, also known as an ozonizer discharge or silent discharge occurs in the discharge space 23. Thus, ultraviolet rays are radiated through the dielectrics 20 and 21 and the transparent electrodes 24 and 25 with high efficiency. Although not shown in the drawing, the surfaces of the transparent electrodes 24 and 25 are covered with an ultraviolet transmissive resin, glass, or the like as necessary to be electrically insulated.

  The first dielectric barrier discharge lamp 6 is filled with xenon gas as the main component of the luminescent gas, and emits ultraviolet rays having a maximum value near 172 nm and having a wavelength range of 120 to 190 nm. The second dielectric barrier discharge lamp 7 is filled with a mixed gas of krypton and chlorine as a main component of the luminescent gas, and emits ultraviolet rays in the wavelength range of 200 to 240 nm having a maximum value near 222 nm. When the processing fluid air 1 is supplied from the processing fluid supply port 2 to the reaction vessel 5, the first dielectric barrier discharge lamp 6 radiates from the first dielectric barrier discharge lamp 6 and has a maximum value in the range of 120 to 190 nm. Ozone is generated in the reaction space region 8 from oxygen in the air 1 by ultraviolet rays. The ozone moves to the reaction space region 9 and is irradiated with ultraviolet rays in a wavelength range of 200 to 240 nm having a maximum value around 222 nm emitted from the second dielectric barrier discharge lamp 7, and active oxygen atoms and oxygen Broken down into molecules. The active oxygen atoms, oxygen molecules, and water 3 that is the object to be processed supplied from the object supply port 4 to the reaction vessel 5 are mixed, and the mixed fluid in the reaction space regions 10 and 11 is mixed with the second and first fluids. The ultraviolet light from the dielectric barrier discharge lamps 7 and 6 is irradiated.

  As a result, methanol, isopropyl alcohol, and the like contained as impurities in water are decomposed and converted to harmless carbon dioxide, water, and the like. The treated water is discharged from the outlet 12 together with the processing air.

  As an advantage of this embodiment, first, since the wavelength range of the ultraviolet light for generating ozone and the wavelength range of the ultraviolet light for decomposing ozone are different, high-efficiency processing is possible, and secondly, In addition to the ultraviolet light from the second dielectric barrier discharge lamp, the mixture of the object to be processed and the pretreated processing fluid is added to the first invitation, methyl ethyl ketone, trichloroethylene, dodecylbenzenesulfonic acid, polyoxyethylene Octylphenyl ether, trimethylamine, tetramethylammonium hydroxide barrier discharge lamps can irradiate short wavelength ultraviolet rays that cannot be generated with conventional low pressure mercury discharge lamps or high pressure arc lamps with high efficiency. Trimethylamine, tetramethylammonium hydroxide, etc. Third, since the light output characteristics of the first and second dielectric barrier discharge lamps do not change depending on the ambient temperature, a large amount of energy is required to make the temperature constant at a relatively low temperature. Water treatment can be performed stably, and fourth, since there is a great degree of freedom in changing the shape of the first and second dielectric barrier discharge lamps, the first step, the second step and the subsequent steps It becomes possible to carry out the process most recently, so that highly efficient processing can be performed.

  In the second embodiment of the present invention, the workpiece supply port 4 is closed in the first embodiment, and the mixture of the workpiece 3 and the processing fluid 1 is mixed and supplied from the processing fluid supply port 2. Is the method. This method has the advantage of simplifying the apparatus.

  The third embodiment of the present invention uses hydrogen peroxide as the processing fluid in the first or second embodiment. Hydrogen peroxide is supplied as hydrogen peroxide water. The supplied hydrogen peroxide solution generates hydroxy radicals in the reaction space regions 8 and 9 by irradiation with ultraviolet rays. The mixture of the object to be processed and the pretreated hydrogen peroxide solution is irradiated with ultraviolet rays in the reaction space regions 10 and 11 to process the object to be processed.

  The fourth embodiment of the present invention is such that, in the first to second embodiments, the object to be treated is industrial waste water or sewage. Also in this embodiment, a pretreatment process such as separation of solids contained in the workpiece may be required, but the workpiece is processed by the same mechanism as in the first to third embodiments. Is done.

  In the first to fourth embodiments, the object to be processed is liquid. In the fifth example, the object to be processed in the first to fifth examples is replaced with gas. For example, if the object to be treated is CFC-11, CFC-12, CFC-114, CFC-112, or CFC-112, which destroys the stratospheric ozone layer, and oxygen is used as the treatment fluid, it is a compound of carbon, chlorine, and fluorine. Fluorocarbon can be converted into harmless lower fluororesin, carbon dioxide, or hydrogen chloride by the treatment method. The hydrogen chloride gas is treated as a sodium compound or the like in a separate process. Various waste gases such as industrial waste gas containing carbon tetrachloride and methyl chloroform can be treated by the method of the sixth embodiment.

  A schematic diagram of a wet cleaning method according to the sixth embodiment is shown in FIG. In the box-shaped cleaning tank 30, two flat dielectric barrier discharge lamps 6 and 7 having a structure for radiating ultraviolet rays on both surfaces are installed. The structure of the dielectric barrier discharge lamp is substantially the same as that shown in FIG. The first dielectric barrier discharge lamp 6 is filled with xenon gas as the main component of the luminescent gas, and emits ultraviolet rays having a maximum value near 172 nm and having a wavelength range of 120 to 190 nm. The second dielectric barrier discharge lamp 7 is filled with a mixed gas of krypton and fluorine as a main component of the luminescent gas, and emits ultraviolet rays in a wavelength range of 240 to 255 nm having a maximum value near 249 nm. When air 1 that is a processing fluid is supplied from the processing fluid supply port 2, the air 1 is emitted by ultraviolet rays in the range of 120 to 190 nm having a maximum value near 172 nm emitted from the first dielectric barrier discharge lamp 6. Ozone is generated in the reaction space region 8 from the oxygen therein. The ozone moves to the reaction space region 9 and is irradiated with ultraviolet rays in a wavelength range of 240 to 255 nm having a maximum value around 249 nm emitted from the second dielectric barrier discharge lamp 7, and active oxygen atoms and oxygen Broken down into molecules. The active oxygen atoms and oxygen molecules are mixed into the water 32 in the cleaning tank 30 through a bubbler 31 provided at the bottom of the cleaning tank 30.

  An object to be treated, such as a plastic bottle 33, is submerged in water 32 mixed with ozone by a support 34, and the outer surface is cleaned by irradiation with ultraviolet rays from the first and second dielectric barrier discharge lamps. By the cleaning, printing on the outer surface of the bottle 33 can be performed with high quality. A method of rotating a plastic bottle 33, which is an object to be processed, by rotating a support 34, and a bottle of third and fourth dielectric barrier discharge lamps facing the first and second dielectric barrier discharge lamps. By providing so as to sandwich 33, the processing speed can be increased.

  FIG. 4 shows a schematic diagram of the photoresist ashing method according to the seventh embodiment. The processing fluid oxygen 1 injected into the ashing duct 40 is converted into ozone by ultraviolet rays emitted from the first dielectric barrier discharge lamp group 41 provided in the ashing duct 40. The first dielectric barrier discharge lamp group 41 is formed by bundling a plurality of hollow coaxial cylindrical dielectric barrier discharge lamps 41a on a pedestal 44 as shown in FIG. 5. The structure of each dielectric barrier discharge lamp 41a is as follows. An aluminum foil 52 serving as an ultraviolet reflector and an electrode is provided inside the inner dielectric 51, and an electrode 54 that transmits ultraviolet light is provided outside the outer dielectric 53 provided coaxially with the inner dielectric 51. Is provided. A hollow cylindrical portion 55 formed by the inner dielectric 51 and the outer dielectric 53 is filled with a light emission gas. When a voltage is applied between the electrodes 52 and 54 by the power supply 26, an ozonizer discharge is generated in the hollow cylindrical portion 55, and ultraviolet rays are radiated from the outer dielectric 54.

  Ozone generated by the ultraviolet rays emitted from the first dielectric barrier discharge lamp group 41 is converted into activated oxygen atoms by the ultraviolet rays from the second dielectric barrier discharge lamp. The photoresist applied to the semiconductor substrate 43, which is the object to be processed, reacts with activated oxygen atoms under the irradiation of ultraviolet rays from the second dielectric barrier discharge lamp group 42, and is ashed. The structure of each discharge lamp 42 a is the same as that of the discharge lamp 41 a and is attached to the pedestal 44. If the positions of the two bases 44 are adjusted, the distance between the lamp group 41 and the lamp group 42 can be adjusted.

  When the second dielectric barrier discharge lamp group 42 selects the luminescent material so as to emit ultraviolet rays having a relatively long wavelength in the range of 240 to 255 nm, 200 to 240 nm, and 300 to 320 nm, photons irradiated to the substrate 43 Therefore, the substrate 43 is less likely to be damaged. Further, when the second dielectric barrier discharge lamp group 42 selects a luminescent material so as to emit ultraviolet rays having a relatively short wavelength of 180 to 200 nm and 160 to 190 nm, the ultraviolet rays are absorbed by oxygen molecules. Since the area is large, the density of highly active oxygen atoms near the substrate surface can be generated extremely high, and since the energy of photons irradiated to the substrate 43 is large, ions are implanted and ashed. The hardened photoresist can also be ashed.

  FIG. 6 shows a schematic diagram of the surface modification method according to the eighth embodiment. The plastic 60 as the object to be processed is installed in the first processing duct 61 filled with the atmosphere of nitrogen 62 supplied from above, and has a wavelength range of 120 to 190 nm from the first dielectric barrier discharge lamp group 63. When irradiated with UV light, the molecular bonds existing on the surface are broken. Thereafter, the plastic 60 is transported to the second processing duct 65 by the transport device 64, and the second dielectric barrier discharge lamp group 66 in the atmosphere of oxygen or air 1 supplied from the processing fluid supply port 2. Is irradiated with ultraviolet rays from the surface, and -COOH groups and -OH groups are generated on the surface. By the treatment as described above, printing and adhesion on the plastic surface can be performed with high quality. In this embodiment, since the object to be processed is in an atmosphere at atmospheric pressure or higher, there is an advantage that the object to be processed is easily moved. In addition, when ultraviolet rays having a wavelength range of 107 to 165 nm are emitted from the first dielectric barrier discharge lamp group 63, it becomes possible to modify the surface of a very stable resin such as a fluororesin. .

  A schematic diagram of a film forming method according to the ninth embodiment is shown in FIG. A first dielectric barrier discharge lamp group 63 having no window member is provided in the vicinity of the light emission gas supply port 75 provided in the upper part of the reaction vessel 70. When the light emission gas argon 74 is supplied from the light emission gas supply port 75, ultraviolet rays having a wavelength range of 107 to 165 nm emitted from the excimer molecules of argon are emitted from the first dielectric barrier discharge lamp group 63. The mixed gas 1 of processing fluid monosilane gas and methane gas supplied from the processing fluid supply port 2 is decomposed and activated by ultraviolet rays in the wavelength range of 107 to 165 nm emitted from the first dielectric barrier discharge lamp group 63, and On the surface of the substrate 71 to be processed, it is reactivated by the ultraviolet rays from the second dielectric barrier discharge lamp group 66 to form a hydrogenated amorphous silicon carbide thin film. When a lamp that emits ultraviolet rays having a relatively long wavelength is adopted as the second dielectric barrier discharge lamp group 66, the energy of photons irradiated to the film is small, so that the film is not damaged and a high quality film is obtained. can get. By disassembling and activating the processing fluid with the ultraviolet light of the first dielectric barrier discharge lamp, and further irradiating the second ultraviolet light during film formation, it is possible to form a high-quality film. A mechanism for adjusting the temperature of the workpiece is incorporated in the workpiece support device 72 to adjust the temperature of the workpiece, or the distance between the workpiece and the first dielectric barrier discharge lamp group 63 by the support tool 73. It is possible to form a higher quality film by adjusting the above. Reference numeral 76 denotes an outlet for discharging gas or processing gas.

  A schematic diagram of the sterilization method according to the tenth embodiment is shown in FIG. As shown in FIG. 8, the dielectric barrier discharge lamp is formed by coaxially arranging three tubular dielectrics, and includes an inner dielectric 51, an intermediate dielectric 88, and an outer dielectric 53. An inner discharge chamber 87 and an outer discharge chamber 86 which are arranged coaxially and are independent are formed. An intermediate electrode 89 embedded in the intermediate dielectric 88 and a transparent electrode 82 and an outer dielectric provided on the inner surface of the inner dielectric 51. 53 is a lamp of a type in which a dielectric barrier discharge is performed in the inner discharge chamber 87 and the outer discharge chamber 86 by applying a voltage between the transparent outer electrodes 54 provided on the outer surface of the 53 by AC power sources 26a and 26b, respectively. Xenon gas is used as the light emission gas in the inner discharge chamber 87 to emit ultraviolet rays in the wavelength range of 120 to 190 nm, and a mixed gas of krypton and fluorine is used as the light emission gas in the outer discharge chamber 86, with a wavelength of 240 to 255 nm. It emits ultraviolet rays in the wavelength range.

  Oxygen gas 1 as a processing fluid is flowed from one end 81 of the tubular inner dielectric 51, and ozone generated by ultraviolet rays having a wavelength range of 120 to 190 nm radiated from the inner discharge chamber 87 in the first reaction space 83. It is ejected from the other end 84 of the inner dielectric 51. The ozone is decomposed in the reaction space 85 by ultraviolet rays having a wavelength range of 240 to 255 nm radiated from the outer discharge chamber 86 to generate active oxygen atoms, and the active oxygen atoms are processed food cups 90. Sterilize the inside of the. Further, the ultraviolet rays in the wavelength range of 240 to 255 nm emitted from the outer discharge chamber 86 that irradiates the inner surface of the food cup 90 are directly applied to the inner surface of the food cup 90 because the ultraviolet rays in this wavelength region have the optimum bactericidal action. It can be sterilized, and therefore can be sterilized and disinfected in a short time.

It is explanatory drawing of the water treatment method using this invention. It is the schematic of a dielectric barrier discharge lamp. It is explanatory drawing of the wet-cleaning method using this invention. It is explanatory drawing of the ashing method of the photoresist using this invention. It is the schematic of the dielectric barrier discharge lamp of another structure. It is explanatory drawing of the surface modification method of the plastics using this invention. It is explanatory drawing of the film-forming method using this invention. It is explanatory drawing of the sterilization method using this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Processing fluid 3 To-be-processed object 6, 7 Dielectric barrier discharge lamp 8, 9, 10, 11 Reaction space area | region 20, 21 Dielectric 23 Discharge space 24, 25 Transparent electrode 26 AC power supply

Claims (1)

A processing method using a dielectric barrier discharge lamp in which an object to be processed and a processing fluid are brought into contact with each other by a first dielectric barrier discharge lamp and a second dielectric barrier discharge lamp that emit ultraviolet rays having different wavelengths. And a wet cleaning method for cleaning the outer surface of the object to be processed by immersing the object to be processed in water,
The processing fluid comprises a fluid containing oxygen,
The treatment fluid is irradiated with ultraviolet rays from the first dielectric barrier discharge lamp to generate ozone, and the ultraviolet rays from the second dielectric barrier discharge lamp are irradiated to generate active oxygen, Mixing the processing fluid into the water,
A processing method using a dielectric barrier discharge lamp, wherein the processing object is processed.

Images