JP2001219053A - Oxidizing method and oxidizing device using dielectric barrier discharge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oxidizing method and an oxidizing device in which the distance between a window through which vacuum ultraviolet light is taken out and the surface of a subject to be treated can be made longer even slightly while using a dielectric barrier discharge lamp. SOLUTION: An oxygen-containing fluid is irradiated with vacuum ultraviolet light which is generated by a dielectric barrier discharge 100 while using argon gas and chlorine gas and has 175 nm wavelength at the peak to generate ozone and an active oxidizing/decomposing material, which are then brought into contact with a subject 9 to be treated in order to oxidize the subject.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for oxidizing an object using a dielectric barrier discharge lamp.
In particular, a method of oxidizing the surface of a metal or a semiconductor material, or a method of oxidizing and removing these objects by dry precision cleaning, and a method of cleaning a panel electrode surface of a liquid crystal panel, and a method of cleaning these. Related to the device.

[0002]

2. Description of the Related Art Conventionally, there has been a method of oxidizing the surface of an object using a low-pressure mercury lamp and an ozone generator. However, the apparatus used in this processing method has a problem in that the apparatus itself becomes expensive, the number of processing steps increases, and the installation floor area increases. In order to solve such a problem, a method of oxidizing an object to be processed using a dielectric barrier discharge lamp in which xenon gas is sealed has recently been proposed. For example, JP-A-7-196
No. 3030.

[0003] The oxidation treatment using a dielectric barrier discharge lamp in which xenon gas is sealed uses vacuum ultraviolet light having a peak at a wavelength of 172 nm, so that a high concentration of ozone and active oxidization are present near the surface of the object to be treated. It has the advantage that decomposition products can be generated, and the speed of processing the object can be significantly improved. However, there is a problem that the vacuum ultraviolet light is easily absorbed by oxygen, and the reaction region of the fluid containing the vacuum ultraviolet light and oxygen cannot be made large. In particular, when directly irradiating the object to be processed with vacuum ultraviolet light, the object to be processed must be brought close to a few millimeters from the vacuum ultraviolet light extraction window, and adjustment with the processing table becomes extremely difficult. Would.

For example, in a liquid crystal panel in which two glass substrates A and B having different sizes are bonded to each other as shown in FIG. 3, cleaning the exposed surface A1 is performed from the light extraction window to the surface to be irradiated. However, there is a problem in that the processing work is extremely difficult because the distance between them becomes large.

[0005] Further, without directly irradiating the object to be processed with vacuum ultraviolet light, the object is irradiated with oxygen to generate ozone and an active oxidative decomposed product, and the ozone and the active oxidative decomposed product are conveyed to another object. Although it is possible in principle to contact the object to be treated at the place, it is practically practical because the reaction area with oxygen is narrow and it is difficult to transport ozone and active oxidative decomposition products. There was a problem that was not the target.

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an oxidation using a dielectric barrier discharge lamp which can increase the distance between a window for extracting vacuum ultraviolet light and the surface of an object. An object of the present invention is to provide a treatment method and an oxidation treatment device.

[0007]

In order to solve the above-mentioned problems, an oxidation method using a dielectric barrier discharge according to the present invention comprises:
The fluid containing oxygen is irradiated with vacuum ultraviolet light having a peak at a wavelength of 175 nm generated by a dielectric barrier discharge by argon gas and chlorine gas to generate ozone and active oxidative decomposition products by a photochemical reaction. It is characterized in that the active oxidative decomposition product is brought into contact with the object to be oxidized to be oxidized. In addition, a wavelength 17 generated by a dielectric barrier discharge using argon gas and chlorine gas.
A fluid containing oxygen is irradiated with vacuum ultraviolet light having a peak at 5 nm to generate ozone and an active oxidative decomposed product by a photochemical reaction, and the ozone and the active oxidative decomposed product are oxidized by being brought into contact with an object to be processed. At the same time, the object to be processed is irradiated with the vacuum ultraviolet light, and the object to be processed is oxidized by a cooperative action thereof.
In addition, the fluid containing oxygen is irradiated with vacuum ultraviolet light having a peak at a wavelength of 175 nm generated by a dielectric barrier discharge caused by argon gas and chlorine gas to generate ozone and active oxidative decomposition products by a photochemical reaction. The ozone and the active oxidative decomposition product are irradiated with far ultraviolet light to increase the activity, and the ozone and the active oxidative decomposition product having the increased activity are brought into contact with the object to be oxidized. Further, a fluid containing oxygen is simultaneously irradiated with vacuum ultraviolet light having a peak at a wavelength of 175 nm generated by a dielectric barrier discharge caused by argon gas and chlorine gas and far ultraviolet light emitted from a far ultraviolet light source. Then, ozone and an active oxidative decomposition product are produced by a photochemical reaction, and the ozone and the active oxidative decomposition product are brought into contact with the object to be oxidized. Further, in the above method, when the object is oxidized, the object is irradiated with at least one of vacuum ultraviolet light and far ultraviolet light. Further, the dielectric barrier discharge lamp is built in a lamp lot having a light extraction window made of synthetic quartz glass, and an inert gas such as nitrogen gas is flowed or filled in the lamp house. And

Further, a processing apparatus using the dielectric barrier discharge lamp according to the present invention is a dielectric barrier discharge lamp which encloses argon gas and chlorine gas and emits vacuum ultraviolet light having a peak at a wavelength of 175 nm, A lamp house surrounding the body barrier discharge lamp and having a light extraction window in a part thereof, means for flowing or filling an inert gas such as nitrogen gas in the lamp house, and an object to be processed in the light extraction window And a processing table arranged so as to be able to irradiate vacuum ultraviolet light in an atmosphere containing oxygen in close proximity.

[0009]

First, the dielectric barrier discharge lamp will be described. Dielectric barrier discharge lamps, like so-called excimer lamps, are filled with a discharge gas that forms excimer molecules in a discharge vessel, and a dielectric barrier discharge (also known as an ozonizer discharge or silent discharge. Discharge Handbook), which is to form excimer molecules according to the reprint, 7th edition, June 1999, page 263) and extract light emitted from the excimer molecules. Quartz glass etc. is used for the dielectric, and the occurrence of arc discharge is suppressed by interposing it in the discharge path, and since the discharge does not concentrate at a specific place, the density of ultraviolet rays generated is almost uniform Can be. Also, since this dielectric barrier discharge lamp contains argon gas and chlorine gas, a wavelength of 175 is used.
It has various features that conventional low-pressure mercury lamps and high-pressure arc discharge lamps emit ultraviolet light with a short wavelength of nm and selectively generate light of a single wavelength close to the line spectrum with high efficiency. ing. The dielectric barrier discharge lamp is disclosed in, for example, JP-A-2-7353 and U.S. Pat. No. 4,837,484. In the present invention, the argon gas and the chlorine gas are used as the discharge gas. However, there are cases where the discharge gas is composed only of these gases and where other gases are mixed with these gases as main components.

[0010] In the dielectric barrier discharge lamp of the present invention,
Argon chloride, which is a compound of an argon atom and a chlorine atom, is excited to be in an excimer state (Ar2Cl *). When the excimer state is again dissociated into argon chloride, light having a wavelength of about 175 nm is generated. It can be seen that irradiating oxygen with the light having a wavelength of 175 nm gives a higher concentration of ozone than irradiating oxygen with a light having a wavelength of 185 nm emitted from a conventional low-pressure mercury lamp. It was also found that active oxidative decomposition products can be obtained from ozone.

Here, a conventional dielectric barrier discharge using xenon gas also has a wavelength of 17.
Emit vacuum ultraviolet light with a peak at 2 nm. However, as described above, since the vacuum ultraviolet light having a wavelength of 172 nm is easily absorbed by oxygen, the vacuum ultraviolet light can be arranged only in a state where the distance between the light extraction window and the surface of the processing object is extremely short. In this regard, the dielectric barrier discharge of the present invention using argon gas and chlorine gas has an emission wavelength of 175.
Since the vacuum ultraviolet light has a peak at nm, the degree of absorption by oxygen is reduced, and as a result, the distance between the light extraction window and the surface of the object can be increased accordingly. For example, in the configuration shown in FIG. 10 described later, as an example of the distance between the light extraction window and the object to be processed, the case of dielectric barrier discharge using xenon gas is 3%.
In contrast, the dielectric barrier discharge using the argon gas and the chlorine gas of the present invention is as large as about 6 mm. Although this difference may be slight numerically, it has a very large practical effect, for example, the surface oxidation treatment of the object having the above-mentioned step can be simplified. Here, the light-exiting window is a light-emitting window of the dielectric-barrier discharge lamp when the object to be irradiated with light emitted from the dielectric-barrier discharge lamp. In the case where the dielectric barrier discharge lamp is housed, the light extraction window of the lamp house corresponds thereto.

Further, even when the object to be treated is flat, when performing a large amount of surface oxidation treatment, irradiation with vacuum ultraviolet light is carried out while carrying a large amount using a belt conveyor or the like. In the case where only a gap of about 3 to 5 mm is provided as in a dielectric barrier discharge using xenon gas, the conveyance process of the belt conveyor becomes extremely difficult. On the other hand, the dielectric barrier discharge using the argon gas and the chlorine gas of the present invention can enlarge the gap, and from this point of view, the practical significance is large.

That is, the oxidation treatment method using the dielectric barrier discharge according to the present invention employs a vacuum ultraviolet light having a wavelength of 175 nm.
The innovative method of using a dielectric barrier discharge lamp that radiates light efficiently enables the generation of high concentrations of ozone and active oxidative decomposed products, thereby enabling the object to be oxidized to be oxidized well. Has a practical effect.
Furthermore, by using vacuum ultraviolet light having a peak at a wavelength of 175 nm, the distance from the light extraction window to the surface of the processing object can be increased, and the processing of the processing object having a step on the surface can be performed favorably. The transfer processing of the object can be simplified.

[0014]

FIG. 1 is an explanatory view of an example of a dielectric barrier discharge lamp (hereinafter also referred to as "lamp") used in the present invention. The discharge vessel 1 has a parallel plate shape made of synthetic quartz glass. Generally, the object to be processed is often a plate-shaped object, and therefore, this shape is convenient for batch processing the surface of the object to be processed. The dimensions and shapes are, for example, 10 cm in length x 10 cm in width in inner dimensions
Those having a height of 0.6 cm are applied. The mesh electrode 2 is composed of a Monel wire provided on the upper and lower portions of the discharge vessel 1.
The inside of the discharge vessel 1 is filled with an argon gas and a chlorine gas, and when power is supplied to the mesh electrode 2 by the power source 3, the inside of the discharge vessel 1 is made of quartz glass as a dielectric and has a plasma length of, for example, 0.6 cm. A dielectric barrier discharge occurs. Quartz glass also serves as a vacuum ultraviolet light extraction part,
Light having a wavelength of 175 nm, which is vacuum ultraviolet light, is emitted out of the discharge vessel 1 from the excimer state obtained by the discharge. Since the treatment for removing organic contaminants targeted by the present invention is generally performed in an oxygen atmosphere, the lamp is particularly preferably made of a material that transmits vacuum ultraviolet light well, such as a synthetic quartz glass plate 5 made of a mesh. Preferably, the electrode 2 is covered, and a space 4 formed between the discharge vessel 1 and the quartz glass plate 5 is filled with an inert gas such as nitrogen gas. Here, as an example, the amount of filled argon is, for example, 32.95.
The filling amount of kPa and chlorine gas is, for example, 0.05 kPa. Further, a voltage of, for example, 4 V and 20 KHz is applied from the mesh electrode 2. In addition to the case where only the argon gas and the chlorine gas are sealed in the inside of the discharge vessel 1, it is possible to use the discharge container 1 in which a very small amount of neon, xenon or the like is sealed.

FIG. 2 shows an apparatus for cleaning the surface of an object to be processed using the dielectric barrier discharge lamp. Inside the processing chamber 7, there is a sample table 8, an object 9 to be processed placed thereon, and a dielectric barrier discharge lamp 100 (hereinafter, simply referred to as a lamp). The object 9 is, for example, a 1 cm × 1 cm glass slide. Further, the processing chamber 7 is provided with an inlet 10 and an outlet 11 for a gas containing oxygen.
For example, a nitrogen gas source 14 and an oxygen gas source 15 are connected via a mixing chamber 12 and a valve 13. In addition, a decomposition device for the discharged ozone can be attached to the outlet 11 as needed. The reason for mixing the nitrogen gas here is to change the partial pressure P of oxygen by flowing nitrogen gas as an inert gas, thereby adjusting the cleaning efficiency. With such an apparatus, the object 9
When the glass slide is irradiated with light having a wavelength of 175 nm from the lamp 100, active oxidative decomposition products are generated according to the principle described above, and organic contaminants attached to the slide glass can be oxidized and removed. The amount of such active oxidative decomposition products generated and the cleaning effect on organic contaminants depend on the influence of the distance d (cm) between the surface of the lamp 100 and the slide glass surface and the partial pressure p (atmospheric pressure) of oxygen in the processing chamber 7. Since it is greatly affected, the partial pressure p of oxygen can be adjusted in the mixing chamber 12, and the sample stage 8 has a vertical movement mechanism (not shown). In the case where the dielectric barrier discharge lamp using argon and chlorine as the discharge gas of the present invention is used, compared with the conventional case using the dielectric barrier discharge lamp using xenon as the discharge gas,
If the conditions such as the oxygen partial pressure p are the same, the distance d from the discharge lamp to the slide glass can be increased.

FIG. 4 shows another example of an apparatus for cleaning the surface of an object to be processed using a dielectric barrier discharge lamp. In this apparatus, a far ultraviolet light source set 101 including a mirror and a low-pressure mercury lamp is arranged along four sides of the dielectric barrier discharge lamp 100 in addition to the dielectric barrier discharge lamp 100. Therefore, the slide glass 9
Gas flowing in the vicinity of the dielectric barrier discharge lamp 1
00 and the far-ultraviolet light from the far-ultraviolet light source set 101. Although not shown in the figure, the dielectric barrier discharge lamp is mounted on a mechanism that can move up and down so that the distance d between the dielectric barrier discharge lamp 100 and the slide glass 9 can be changed. Here, the vacuum ultraviolet light emitted from the dielectric barrier discharge lamp 100 refers to light having a wavelength of 1 nm to 200 nm having a peak at a wavelength of 175 nm, and the far ultraviolet light emitted from the far ultraviolet light source set 101 is a wavelength. 200n
m to 370 nm. Also in this embodiment, when the dielectric barrier discharge lamp of the present invention using argon and chlorine as a discharge gas is used, compared with the case of using a dielectric barrier discharge lamp using xenon as a discharge gas, the oxygen partial pressure and the like are reduced. The distance d can be increased under the same condition.

FIG. 5 is an explanatory view showing a method for oxidizing and removing organic contaminants adhering to a metal surface. That is, ozone and active oxidative decomposition products are generated by 175 nm light, which is vacuum ultraviolet light emitted from the dielectric barrier discharge lamp, and organic contaminants attached to the metal surface by the ozone and active oxidative decomposition products are removed. A method for oxidizing and removing organic contaminants by irradiating 175 nm light, which is vacuum ultraviolet light, directly to the metal surface will be described. First, the configuration of the apparatus will be described. The dielectric barrier discharge lamp 102 is disposed in an aluminum mirror 16 whose surface is coated with magnesium fluoride, and
Below the object 02, an aluminum plate 17 which is an object to be treated and on the surface of which an organic contaminant is adhered is arranged. Here, as the lamp 102, the one shown in FIG. 1 can be used, but a double cylindrical lamp described later can also be used. The atmosphere in the mirror 16 is such that air flows from above the mirror 16 so as to cool the lamp 102 and the mirror 16 and the like toward the aluminum plate 17.
The total pressure of the atmosphere is about 1 atmosphere, and the oxygen partial pressure is
For example, about 0.21 atm. With such a configuration, 175 nm light, which is vacuum ultraviolet light, is efficiently emitted from the lamp 102 having an argon gas and a chlorine gas. The light is irradiated to the oxygen gas in the incoming air to generate ozone by a photochemical reaction, and the ozone is also irradiated with the light of the vacuum ultraviolet light to cause active oxidative decomposition. Things are created. When the active oxidative decomposition product comes into contact with the aluminum plate 17, organic contaminants adhering to the aluminum plate 17 can be washed well. In this embodiment, the oxygen gas can be efficiently delivered onto the aluminum plate 17 using the mirror 16, and the aluminum plate 17 is directly irradiated with the light reflected by the mirror 16 and the direct light from the lamp 102, or the vicinity thereof is irradiated. As a result, a photochemical reaction is caused, so that the cleaning effect can be made extremely high. Also in this embodiment, when the dielectric barrier discharge lamp of the present invention using argon and chlorine as a discharge gas is used, compared with the case of using a conventional dielectric barrier discharge lamp using xenon as a discharge gas, an oxygen content is reduced. The distance d can be increased under the condition that the conditions such as pressure are the same.

FIG. 6 shows an example of a double cylindrical dielectric barrier discharge lamp 102. The discharge vessel 18 has a hollow cylindrical shape in which an inner tube 23 and an outer tube 24 made of quartz glass are coaxial, and has a substantially bamboo ring shape. The outer tube 24 also serves as a dielectric and a light extraction portion of the dielectric barrier discharge lamp, and the outer surface of the inner tube 23 has an aluminum film electrode 1 also serving as a reflection film.
The outer tube 24 is provided with a metal mesh electrode 20 for transmitting light. Discharge space 21
Is filled with argon gas and chlorine gas as discharge gases. The reticulated electrode 20 has an electrode oxidation preventing coat 2
2 are provided and are not shown, but may be provided also on the electrode 19 side. In general, when treating the surface of a roll-wound film, the double-cylindrical dielectric barrier discharge lamp having such a shape is formed by moving the film in a direction perpendicular to the lamp tube axis.
It is convenient to treat the surface continuously. still,
An example of such a lamp is as follows.
00 mm, the outer diameter D1 of the inner tube 23 is 16 mm, and the outer tube 2 is
4 has an inner diameter D2 of 24 mm. Further, the structure of the dielectric barrier discharge lamp is not limited to the structure in which both electrodes are located on the opposite side to the discharge space via the dielectric as described above. Either one of the electrodes may be arranged in the discharge vessel, that is, in the discharge space.

FIG. 7 is an explanatory view showing a method of oxidizing and removing organic contaminants adhering to a metal surface among the oxidizing methods. That is, ozone and active oxidative decomposition products are generated by 175 nm light, which is vacuum ultraviolet light emitted from a dielectric barrier discharge lamp, and the ozone and active oxidative decomposition products are converted to far ultraviolet light having a wavelength of 254 nm. Irradiation to generate active oxidative decomposition products and increase the activity to oxidize and remove organic contaminants on the metal surface.
First, the configuration of the apparatus will be described. The reaction duct 25 has a generally flat shape, in which a double-cylindrical dielectric barrier discharge lamp 102 and a low-pressure mercury lamp 103 have a tube axis. Place in parallel and spaced apart. The reaction duct 25 is configured so that the air flowing from the lamp 102 flows toward the lamp 103,
3 is an aluminum plate 17 which is the object to be cleaned.
Is arranged. The aluminum plate 17 has a lamp 1
02 and the light emitted from the lamp 103 may not be directly applied, but depending on the position, the low-pressure mercury lamp 103 may be used.
It can be made to receive far ultraviolet light from. In such a configuration, the air that has flowed into the reaction duct 25 receives light having a wavelength of 175 nm, which is vacuum ultraviolet light emitted from the lamp 102, on the upstream side of the duct. Then, oxygen causes a photochemical reaction to generate ozone, and an active oxidative decomposition product is also generated from the ozone. These ozone and active oxidative decomposition products are blown toward the downstream side, and further receive the light having a wavelength of 254 nm, which is the far ultraviolet light emitted from the lamp 103, so that the activity is further enhanced. Then, by contacting the aluminum plate 17 disposed further downstream, organic contaminants attached to the surface can be oxidized and removed.

FIG. 8 is an explanatory view showing a method of oxidizing and removing organic contaminants adhering to the metal surface among the oxidizing methods. That is, ozone and active oxidative decomposition products are generated by 175 nm light, which is vacuum ultraviolet light emitted from a dielectric barrier discharge lamp, and the ozone and active oxidative decomposition products are brought into contact with a metal surface having organic contaminants. And at the same time, 254n which is far ultraviolet light emitted from a low-pressure mercury lamp provided separately from the dielectric barrier discharge lamp.
m light is also applied to the metal surface. That is, the oxidation treatment is performed using two lamps, a dielectric barrier discharge lamp and a low-pressure mercury lamp, and at least one of the two is used to directly irradiate the metal surface. First, the configuration of the apparatus will be described. In the mirror 16, three double-cylindrical dielectric barrier discharge lamps 102 are arranged in substantially the same plane, and two low-pressure mercury lamps 103 are further mounted on the lamp 102.
Are arranged in substantially the same plane in parallel with the plane constituted by. In this case, "parallel" means that the lamp axes are parallel to each other, and the lamps are arranged in a zigzag shape when viewed from the lamp axis direction. The mirror 16 can be the same as that described with reference to FIG. On the surface of the aluminum plate 17, there are places where irradiation with 254 nm light, which is far ultraviolet light emitted from the lamp 103, and places where it is not, and 175 nm light, which is vacuum ultraviolet light emitted from the lamp 102. Even with this light, illuminance unevenness occurs on the aluminum plate 17. For this reason, the sample stage 8 on which the aluminum plate 17 is placed is, for example,
It can be moved with z. And the lamp 10
2. The arrangement of the lamp 103 and the selection of the amplitude of the lamp 103 adjust the way of receiving the far ultraviolet light while making the illuminance of the vacuum ultraviolet light uniform on the aluminum plate 17. With such a configuration, the aluminum plate 1 placed on the sample table 8
Reference numeral 7 denotes vacuum ultraviolet light emitted from the lamp 102.
By receiving the light of 75 nm, oxygen contained in the air causes a photochemical reaction to generate ozone and active oxidative decomposition products. At the same time, by receiving the light of 254 nm, which is far ultraviolet light emitted from the lamp 103, the activity of the ozone and the active oxidative decomposition products is increased, and the organic contaminants on the aluminum plate 17 are oxidized and removed. it can. Also in this embodiment, when the dielectric barrier discharge lamp of the present invention using argon and chlorine as a discharge gas is used, compared with the case of using a dielectric barrier discharge lamp using xenon as a discharge gas, the oxygen partial pressure and the like are reduced. The distance d can be increased under the same condition.

In the embodiment described above, organic contaminants adhering to the surface of the aluminum plate are oxidized and removed. Next, an apparatus having substantially the same configuration as the apparatus shown in FIG. The so-called optical ashing for oxidizing and removing the photoresist applied to the substrate will be described. In this case, by equipping the sample stage 8 with a heating mechanism such as a heater or a pipe for flowing cooling water, the temperature of the semiconductor wafer can be heated to a predetermined temperature. An ashing process can be performed by irradiating the photoresist with radiation emitted from 103.

Next, a method of forming a silicon oxide film on the surface of a semiconductor wafer using an apparatus substantially similar to the apparatus shown in FIG. 8 will be described. A silicon wafer as an object to be processed is placed on the sample table 8, and five dielectric barrier discharge lamps 102 and four low-pressure mercury lamps 103 are arranged in a zigzag as described above. When the temperature of the sample stage 8 is heated to, for example, 400 ° C. and reciprocated at 5 Hz, a dense silicon oxide film having a thickness of 10 nm can be formed on the silicon wafer. Could be achieved in time. The above-described apparatus for removing organic contaminants and unnecessary photoresist is not shown, but is provided with a mechanism for blowing off such exhaust, whereas the apparatus for removing an oxide film according to this embodiment is not shown. The apparatus differs in that a mechanism for stably holding and controlling the fluid existing between the lamp and the workpiece is provided. Such a mechanism is also omitted in FIG.

Generally, forming a thin oxide film on the surface of a silicon wafer is commonly performed in an insulating layer forming step in the manufacture of semiconductor devices. However, the conventional method is carried out by heating at a high temperature of, for example, about 850 ° C. to 1000 ° C., compared with a high-humidity electric furnace, whereas the method of forming an oxide film of the present invention has significantly lower humidity and lower humidity. A high-quality oxide film can be obtained at a temperature. Also in this embodiment, when the dielectric barrier discharge lamp of the present invention using argon and chlorine as a discharge gas is used, compared with the case of using a dielectric barrier discharge lamp using xenon as a discharge gas, the oxygen partial pressure and the like are reduced. The distance d can be increased under the same condition.

Next, another embodiment of a method of forming an oxide film on a silicon wafer will be described with reference to FIG. The discharge vessel 1 of the dielectric barrier discharge lamp is made of quartz glass and has, for example, a flat type having a discharge space 21 therein. The discharge vessel 21 has 175 vacuum ultraviolet light.
Argon gas and chlorine gas are filled to generate light of nm. Although the electrode 2 is provided outside the discharge vessel 21 but the emitted light is extracted only in one direction, the aluminum film 6 also serving as a mirror is formed on one electrode, and the other is a mesh electrode, so that it is efficient. Synchrotron radiation can be extracted. Further, since the present apparatus is used in an oxygen atmosphere, the quartz glass is provided with an antioxidant coat 22. The sample stage 28 is made of quartz glass, a silicon wafer 26 is placed on the stage 28, and a heater 27 for heating is built therein. As an example of such a dielectric barrier discharge lamp, the discharge vessel 1 is quartz glass having a thickness of 1 mm, and has an inner dimension of 20 cm × 20 cm × 0.6 cm.
m. Also in this embodiment, when the dielectric barrier discharge lamp of the present invention using argon and chlorine as a discharge gas is used, compared with the case of using a dielectric barrier discharge lamp using xenon as a discharge gas, the oxygen partial pressure and the like are reduced. The distance d can be increased under the same condition.

Here, the dielectric barrier discharge lamp filled with argon gas and chlorine gas will be described in more detail. The dielectric barrier discharge lamp has a wavelength of 200 nm.
Since it emits vacuum ultraviolet light of shorter wavelength,
The discharge vessel must be made of a dielectric that transmits light in that wavelength range, but of course, depending on the application, the light extraction may be in all directions of the lamp, or in one particular direction. There can be. Therefore, it is sufficient that at least the light extraction portion has a structure that transmits light in the wavelength range, and the material of the extraction portion is not limited to synthetic quartz glass, but includes sapphire, alkali metal halide, and the like. A single crystal of an alkaline earth metal halide may be used.
Then, a portion of the discharge vessel from which the ultraviolet light is not extracted may be provided with a reflective coat or an electrode serving also as a reflective coat.

Similarly, from a wavelength of 200 nm to a wavelength of 300 n
The far-ultraviolet light source that emits m-ultraviolet light is not limited to the low-pressure mercury lamp described above, but may be a high-pressure mercury lamp that emits light in these wavelength ranges, a wavelength of 240 nm to 255 nm.
And a krypton-fluorine excimer laser emitting krypton.

FIG. 10 shows an oxidation treatment apparatus including a dielectric barrier discharge lamp and a transport mechanism such as a belt conveyor. This oxidation treatment apparatus includes a double cylindrical dielectric barrier discharge lamp 33a, 33b, 33c having a structure similar to that of the dielectric barrier discharge lamp shown in FIG. 7 instead of the parallel plate type discharge vessel 1 in FIG. Instead of being built-in and being covered with the synthetic quartz glass plate 5 in FIG. 1, a light extraction window 3 made of synthetic quartz glass is provided in a metal container 30 also serving as a light reflecting plate.
1 is provided. Double cylindrical dielectric barrier discharge lamps 33a, 33b, 33c
Is, for example, an outer diameter of 26.6 mm and a discharge gap length of 5
mm, the total length is 300 mm. Below the light extraction window 31, there is a transport mechanism 40 (processing table) composed of a belt conveyor or the like. The workpiece W such as a liquid crystal panel is placed on the transport mechanism 40 and transported sequentially so that the vacuum ultraviolet light transmitted through the light extraction window 31 is irradiated. here,
A fluid containing oxygen is present in the gap between the light extraction window 31 and the workpiece W, and is irradiated with vacuum ultraviolet light having a peak at a wavelength of 175 nm to generate ozone and active oxidative decomposition products, and the workpiece is processed. React W. Note that the transport mechanism 40 is not limited to a mechanism such as a belt conveyor, and may be a mechanism in which the processing stage moves up and down.

When a dielectric barrier discharge was performed in such an oxidation treatment apparatus, vacuum ultraviolet light having a center at a wavelength of 175 nm was emitted with high efficiency. Further, by flowing an inert gas such as nitrogen gas at a rate of several liters per minute into the space 4, in addition to protecting the electrodes 20a, 20b, and 20c, absorption of vacuum ultraviolet light in the space 4 is eliminated. A flat light source device was obtained. In this embodiment, since a large number of expensive synthetic quartz glass plates are not used, there is an advantage that a flat light source device can be obtained at low cost. Further, as compared with the case of emitting vacuum ultraviolet light having a peak at a wavelength of 172 nm, the light extraction window 3
The gap between the workpiece 1 and the workpiece W can be increased, and the complexity of placing and transporting the workpiece can be reduced.

In the method for oxidizing an object to be treated according to the present invention, the surface of the metal is oxidized by alumite treatment of aluminum, surface oxidation treatment as a pre-treatment for printing on stainless steel, and further, vapor deposition on a glass plate. It can also be used for an oxidation treatment for improving the transparency of the metal oxide.

As a method for cleaning the surface of the glass,
It can be used for precision cleaning for pre-processing of distributing electrodes and wiring to the glass of the liquid crystal display panel. The technique of the present invention is also useful for improving the thermocompression bonding strength of gold.

[0031]

The oxidation method using the dielectric barrier discharge according to the present invention uses a dielectric barrier discharge lamp that emits vacuum ultraviolet light that is light of a wavelength of 175 nm.
Since a high concentration of ozone and active oxidative decomposition products can be generated near the surface of the object, the speed of oxidizing the object is significantly increased. Further, since vacuum ultraviolet light having a peak at a wavelength of 175 nm is used, the distance between the light extraction window and the surface of the processing object can be increased.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an example of a planar dielectric barrier discharge lamp used in the present invention.

FIG. 2 is an explanatory view of a surface cleaning method of the present invention.

FIG. 3 is an explanatory diagram of a general technique relating to the present invention.

FIG. 4 is an explanatory view of a surface cleaning method of the present invention.

FIG. 5 is an explanatory view of an organic matter removing method of the present invention.

FIG. 6 is an explanatory diagram of an example of a cylindrical dielectric barrier discharge lamp used in the present invention.

FIG. 7 is an explanatory diagram of the method for oxidizing and removing organic contaminants of the present invention.

FIG. 8 is an explanatory diagram of the method for oxidizing and removing organic contaminants of the present invention.

FIG. 9 is an explanatory diagram of a low-temperature oxidation method for a silicon wafer according to the present invention.

FIG. 10 is an explanatory diagram of a light source device using the double cylindrical dielectric barrier discharge lamp of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Discharge container 2 Reticulated electrode 3 Power supply 7 Processing room 8 Sample stand 100 Dielectric barrier discharge lamp 101 Far ultraviolet light source set 102 Dielectric barrier discharge lamp 103 Low pressure mercury lamp

Claims (7)

[Claims] 1. An oxygen-containing fluid is irradiated with vacuum ultraviolet light having a peak at a wavelength of 175 nm generated by a dielectric barrier discharge using argon gas and chlorine gas to generate ozone and active oxidative decomposition products by a photochemical reaction. An oxidation method using a dielectric barrier discharge, characterized in that the ozone and the active oxidative decomposition product are brought into contact with an object to be oxidized. 2. A method of irradiating a fluid containing oxygen with vacuum ultraviolet light having a peak at a wavelength of 175 nm generated by a dielectric barrier discharge using argon gas and chlorine gas to generate ozone and active oxidative decomposition products by a photochemical reaction. At the same time, the ozone and the active oxidative decomposition product are brought into contact with the object to be oxidized, and the vacuum ultraviolet light is also applied to the object to be oxidized, whereby the object is oxidized by their cooperative action. An oxidation method using a dielectric barrier discharge characterized by the following. 3. An oxygen-containing fluid is irradiated with vacuum ultraviolet light having a peak at a wavelength of 175 nm generated by a dielectric barrier discharge using argon gas and chlorine gas to generate ozone and active oxidative decomposition products by a photochemical reaction. By irradiating the ozone and the active oxidative decomposition product with far ultraviolet light to increase the activity, the ozone and the active oxidative decomposition product having the increased activity are brought into contact with the object to be oxidized. Oxidation method using dielectric barrier discharge. 4. A method according to claim 1, wherein a vacuum ultraviolet light having a peak at a wavelength of 175 nm generated by a dielectric barrier discharge of argon gas and chlorine gas and far ultraviolet light radiated from a far ultraviolet light source are converted into a fluid containing oxygen. Simultaneously irradiate to generate ozone and active oxidative decomposition products by photochemical reaction, and then contact the ozone and active oxidative decomposition products with the object to be oxidized to use a dielectric barrier discharge. Oxidation method. 5. The method according to claim 3, wherein the object is irradiated with at least one of vacuum ultraviolet light and far ultraviolet light when the object is oxidized. Oxidation method using a dielectric barrier discharge lamp. 6. The dielectric barrier discharge lamp is incorporated in a lamp lot having a light extraction window made of synthetic quartz glass, and an inert gas flows or fills the lamp house. An oxidation method using the dielectric barrier discharge lamp according to claim 1. 7. An argon gas and a chlorine gas are filled and a wavelength of 17
A dielectric barrier discharge lamp that emits vacuum ultraviolet light having a peak at 5 nm, a lamp house surrounding the dielectric barrier discharge lamp and having a light extraction window in a part thereof, and flowing an inert gas into the lamp house. Or a means for filling, and a processing table arranged so as to be able to irradiate vacuum ultraviolet light in an atmosphere containing oxygen in the vicinity of the object to be processed to the light extraction window. Oxidation treatment equipment using discharge lamps.