JP2003080191A - Light irradiation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light irradiation device capable of certainly treating an object to be treated by suppressing the temperature rise of a window member for taking out the excimer light of a lamp house having a dielectric barrier discharge lamp housed therein and capable of preventing the adhesion of a pollutant to the window member. SOLUTION: The light irradiation device is equipped with the dielectric barrier discharge lamp 2 and the lamp house 1 housing the dielectric barrier discharge lamp 2 and having the window member 5 for taking out excimer light formed thereto and operated in such a state that the lamp house is substituted with an inert gas. An inert gas jet mechanism 6 is provided in the lamp house 1 and the inert gas ejected from the inert gas jet mechanism 6 is directly sprayed on the window member 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light irradiation device equipped with a dielectric barrier discharge lamp.

[0002]

2. Description of the Related Art Recently, by irradiating an object to be processed made of metal, glass, or other material with vacuum ultraviolet rays having a wavelength of 200 nm or less, the vacuum ultraviolet rays and the active oxygen such as ozone generated by the vacuum ultraviolet rays cause the object to be treated. A technique for treating a treatment object, for example, a cleaning treatment technique for removing organic contaminants adhering to the surface of a treatment object has been developed and put into practical use.

In such a light irradiating device for treating ultraviolet rays, as a light source for radiating ultraviolet rays, an appropriate discharge gas is filled in a discharge vessel partially formed of a dielectric material, and the discharge vessel is concerned. A dielectric barrier discharge lamp has been developed in which an excimer is generated and excimer light is emitted by generating a dielectric barrier discharge inside. For example, Japanese Patent Application Laid-Open No. 1-144560 describes a dielectric barrier discharge lamp in which a discharge gas is filled in a hollow cylindrical discharge vessel at least a part of which is made of quartz glass which is a dielectric. ing.

In such a dielectric barrier discharge lamp, by using, for example, xenon gas as a discharge gas, vacuum ultraviolet rays having a peak at a wavelength of 172 nm, which is excimer light by xenon excimer, are emitted.
Further, it is known that by using, for example, a mixed gas of argon and chlorine gas as a discharge gas, vacuum ultraviolet rays having a peak at a wavelength of 175 nm, which is excimer light by an argon-chlorine excimer, are emitted.

A light irradiation device having a dielectric barrier discharge lamp is disclosed in Japanese Patent Laid-Open No. 174793/1993.
A cylindrical dielectric barrier discharge lamp is housed in a lamp house having a box-shaped casing having an opening on one surface and a plate-shaped window member for extracting excimer light provided in the opening of the casing. It is described.

However, in such a light irradiation device,
When a dielectric barrier discharge lamp that emits vacuum ultraviolet rays is used, the vacuum ultraviolet rays from the dielectric barrier discharge lamp are high because oxygen existing in the lamp house absorbs the vacuum ultraviolet rays from the dielectric barrier discharge lamp. It cannot be taken out efficiently from the window member of the lamp house. Therefore, the concentration of oxygen existing in the lamp house is reduced by replacing the inside of the lamp house with an inert gas.

[0007]

In recent years, there has been a tendency to use a dielectric barrier discharge lamp having a large light output in order to increase the processing speed of an object to be processed or to reliably process the object. As a result, the temperature of the window member has risen. The vacuum ultraviolet rays that have passed through the window member are emitted to the processing space, but this processing space is in an environment where the vacuum ultraviolet rays are easily absorbed because oxygen or a specific processing gas exists. It is in. Therefore, in order to reduce the absorption of vacuum ultraviolet rays as much as possible, the distance between the window member and the object to be processed is extremely close to, for example, about 2 mm.

As a result, the radiant heat of the window member, which has become high in temperature, is radiated to the object to be processed and the object to be processed becomes high in temperature, and the organic pollutants originally attached to the object to be processed are vacuum ultraviolet rays and ozone. Where the active oxygen is removed by dry cleaning, the heat from the window member deteriorates the organic pollutants of the object to be processed, and conversely the dry cleaning cannot completely remove the contaminant.

Further, when the temperature of the window member becomes high, contaminants adhere to the window member and the vacuum ultraviolet rays passing through the window member are reduced depending on the kind of gas generated when the object is treated. However, there is a problem in that the processing efficiency of (1) is reduced and the object cannot be processed.

The present invention has been made based on the above circumstances, and an object thereof is to suppress a temperature rise of a window member for extracting excimer light of a lamp house having a dielectric barrier discharge lamp housed therein. By doing so, it is an object of the present invention to provide a light irradiating device capable of surely treating the object to be treated and preventing contaminants from adhering to the window member.

[0011]

In order to solve the above-mentioned problems, a light irradiating device according to claim 1 is a dielectric barrier discharge lamp for generating excimer light by dielectric barrier discharge, and this dielectric barrier discharge. In a light irradiating device that operates in a state in which the inside of the lamp house is replaced with an inert gas, the lamp house is provided in the lamp house. Is provided with an inert gas ejection mechanism, and the inert gas ejection mechanism is configured such that the inert gas ejected from the inert gas ejection mechanism is directly blown to the window member. And

The light irradiating device according to a second aspect is the first aspect.
The light irradiating device according to claim 1, in which the inert gas jetting mechanism has an inert gas flowing part through which an inert gas flows, and the inert gas flowing part is provided outside the window member. While being arranged along the periphery, an inert gas ejection hole is formed in the direction of the window member, so that the inert gas ejected from the inert gas ejection hole is directly blown to the window member. It is characterized by becoming.

A light irradiation device according to a third aspect of the present invention is the light irradiation device according to the first aspect.
The light irradiating device according to claim 1, in particular, in the casing, a light reflecting plate for reflecting the excimer light generated from the dielectric barrier discharge lamp in the direction of the window member is provided, The inert gas jetting mechanism has an inert gas flowing portion through which an inert gas flows, the inert gas flowing portion being at a position separated from the window member, and the dielectric of the light reflecting plate. An inert gas ejection hole is formed on the opposite side of the barrier discharge lamp in the direction of the window member, and the inert gas ejected from the inert gas ejection hole is formed on the light reflection plate. It is characterized in that it is adapted to be directly blown to the window member through the vent hole.

A light irradiating device according to a fourth aspect is the first aspect.
The light irradiation device according to claim 1, in particular, in the lamp house, a partition plate that transmits excimer light is disposed between the dielectric barrier discharge lamp and the window member, and the inert gas The gas ejection mechanism has an inert gas flow part in which an inert gas flows, the inert gas flow part extending between the partition plate and the window member,
An opening for ejecting an inert gas is formed at an end of the inert gas flow section, and the inert gas ejected from the opening is blown between the partition plate and the window member. It is characterized by being.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The light irradiation device of the present invention will be described in detail below. FIG. 1 is an explanatory cross-sectional view showing the configuration of an example of the light irradiation device of the present invention. In this light irradiation device, three dielectric barrier discharge lamps 2 for generating excimer light are arranged in a lamp house 1. A cooling block 3 for cooling the dielectric barrier discharge lamp 2 is arranged in the lamp house 1, and a lower surface of the cooling block 3 has a diameter larger than the outer diameter of the dielectric barrier discharge lamp 2. Are formed so as to be spaced apart from each other and lined up, and the dielectric barrier discharge lamp 2 is provided along each of the grooves 31.
Are arranged.

As shown in FIG. 2, the dielectric barrier discharge lamp 2 is provided with a hollow cylindrical discharge vessel 21.
More specifically, the discharge vessel 21 includes one cylindrical wall member 22 made of a dielectric material and one wall member 22 arranged along the cylinder axis in the one wall member 22. The other wall member 23 made of a dielectric material having an outer diameter smaller than the inner diameter
Both ends of each of the one wall member 22 and the other wall member 23 are joined by the sealing wall part 24, and a cylindrical discharge is formed between the one wall member 22 and the other wall member 23. A space S is formed. A discharge gas is enclosed in the discharge container 21.

One wall member 22 of the discharge vessel 21 is provided with one net-like electrode 26 made of a conductive material such as a wire mesh in close contact with the outer surface 25 thereof, and the other wall material of the discharge vessel 21. The other electrode 28 in the form of a film made of aluminum is provided on 23 so as to cover the outer surface 27 which is the inner peripheral surface thereof.

The dielectric material forming the one wall member 22 and the other wall member 23 in the discharge vessel 21 is transparent to the excimer light emitted in the discharge vessel 21, for example, synthetic quartz glass. Can be used. As the discharge gas sealed in the discharge vessel 21, for example, xenon gas, a mixed gas of argon and chlorine, or the like can be used.

Returning to FIG. 1, the light irradiation device will be described.
Reference numeral 2 is a cooling fluid flow path member for circulating a cooling fluid, in which a cooling body such as water flows to cool the cooling block 3. Then, the dielectric barrier discharge lamp 2 in contact with the cooling block 3 can be cooled. In the illustrated example, a light reflection plate 41 made of aluminum and having a V-shaped cross section is provided between the grooves 31 adjacent to each other on the lower surface of the cooling block 3, and the grooves 31 at both ends are provided.
A light reflection plate 42 made of aluminum is provided on the outer side of the so as to be inclined such that its reflection surface faces inward and downward.

A window member 5 for taking out excimer light generated from the dielectric barrier discharge lamp 2 is formed on the lower plate 11 of the lamp house 1. The window member 5 can be made of a material that has a property of transmitting excimer light from the dielectric barrier discharge lamp 2, for example, synthetic quartz glass.

Inside the lamp house 1, an inert gas ejection mechanism 6 for arranging the inside of the lamp house 1 with an inert gas, for example, nitrogen gas, is arranged. And
The inert gas ejected from the inert gas ejecting mechanism 6 is exhausted from the exhaust hole 10 of the lamp house 1 so that the interior of the lamp house 1 can be replaced with the inert gas. In the embodiment of FIG. 1, the inert gas jetting mechanism 6 has an inert gas flowing part 61 through which the inert gas flows, and the inert gas flowing part 61 is made of aluminum having ultraviolet resistance. There is.

As shown in the perspective view of FIG. 3 in which only the window member 5 and the inert gas ejection mechanism 6 are taken out, the inert gas flow section 61 is arranged along the outer periphery of the window member 5 and Inert gas ejection holes 62 are formed at equal intervals in the direction of the member 5. Then, the inert gas ejected from the inert gas ejection hole 62 is directly blown to the window member 5. As a result, the distance that the inert gas ejected from the inert gas ejection hole 62 near the window member 5 flows to the window member 5 can be extremely shortened,
The window member 5 can be cooled efficiently and surely,
The temperature rise of the window member 5 can be suppressed. Therefore,
It is possible to reliably process the object to be processed and prevent contaminants from adhering to the window member.

In FIG. 3, the inert gas ejection hole 62 is
Is formed on only one side of the inert gas flowing portion 61, but may be formed on all four sides. Further, as shown in FIG. 3, when the inert gas flowing portion 61 is arranged along the entire outer periphery of the window member 5, the inert gas flowing portion 61 is installed in the lamp house 1
Although not shown in the drawing in some cases, it may also serve as a fixing means for fixing to the lower plate 11 of the window member 5, not the entire outer periphery of the window member 5.
It may be arranged only along the outer periphery of one side.

FIG. 4 is a sectional view for explaining another embodiment of the light irradiating device of the present invention. The difference from the light irradiating device of FIG. 1 lies in the arrangement state of the inert gas ejection mechanism in the lamp house. It is different. Note that the same reference numerals as those in FIG. In FIG. 4, the inert gas jetting mechanism 6A is provided in the lamp house 1 and has an inert gas flowing part 61A through which the inert gas flows, and the inert gas flowing part 61A is resistant to ultraviolet rays. Made of aluminum pipes that have.

As shown in FIG. 4, the inert gas flowing portion 61A is arranged at a position separated from the window member 5 and on the opposite side of the light reflecting plate 42 from the dielectric barrier discharge lamp 2. . Further, as shown in the perspective view of FIG. 5 in which only the window member 5, the inert gas ejection mechanism 6A, the light reflection member 41 and the dielectric barrier discharge lamp 2 are taken out, the inert gas flowing portion 61A has a pipe shape. And dielectric barrier discharge lamp 2
And the inert gas ejection holes 62A are formed at equal intervals in the direction of the window member 5. Then, the inert gas ejected from the inert gas ejection hole 62A passes through the ventilation hole 420 formed in the light reflection plate 42 and is directly blown to the window member 5.

As a result, since the inert gas flowing section 61A is arranged on the side of the light reflecting plate 42 opposite to the dielectric barrier discharge lamp 2, the excimer light emitted from the dielectric barrier discharge lamp 2 is not blocked. The excimer light can be used efficiently, and the pipe-shaped inert gas flowing part 61A
Are arranged in parallel with the dielectric barrier discharge lamp 2, so that the light reflection plate 4 existing in the narrow space in the lamp house 1
The inert gas flow section 61A can be arranged in the lamp house without any interference without interfering with the first and second parts 42 and the dielectric barrier discharge lamp 2, and at the same time, the inert gas ejection hole 62A
The window member 5 can be cooled by the inert gas ejected from, and the temperature rise of the window member 5 can be suppressed. Therefore, it is possible to surely process the object to be processed and prevent contaminants from adhering to the window member.

FIG. 6 is a sectional view showing another example of the light irradiation device of the present invention. The difference from the light irradiation device of FIG. 1 is that the dielectric barrier discharge lamp 2 and the window member are provided in the lamp house 1. 5
And a partition plate 7 that transmits excimer light from the dielectric barrier discharge lamp 2 are formed between them, and the arrangement state of the inert gas ejection mechanism in the lamp house is different. The partition plate 7 can be made of a material that is transparent to excimer light, for example, synthetic quartz glass similar to the window member 5. Note that the same reference numerals as those in FIG.

In FIG. 6, the inert gas jetting mechanism 6B is provided in the lamp house 1 and has an inert gas flowing portion 61B through which the inert gas flows, and this inert gas flowing portion 61B. An opening 62B that extends toward the space between the partition plate 7 and the window member 5 is formed at the end of the inert gas flowing portion 61B. Then, the inert gas ejected from the opening 62B is blown between the partition plate 7 and the window member 5.

As a result, the inert gas first flows into only the narrow space between the window member 5 and the partition plate 7, and it is difficult for the inert gas to flow into the other spaces of the lamp house 1. It is possible to cool efficiently and suppress the temperature rise of the window member 5. Therefore, it is possible to surely process the object to be processed and prevent contaminants from adhering to the window member.

A cooling experiment of a window member was conducted using the light irradiation apparatus of the present invention shown in FIG. The experimental conditions are as follows. <Dielectric Barrier Discharge Lamp> Input power: 990 W Radiation wavelength: 172 nm Three dielectric barrier discharge lamps were used and the total ultraviolet radiation intensity was set to 50 mW / cm ² . <Inert gas> Gas type: Nitrogen gas flow rate: 30 liters / min. For comparison, a dielectric barrier discharge lamp with the same performance is used and an inert gas is flown from the upper part of the lamp house 1. A comparative experiment was also conducted to understand the cooling effect of the window member of the conventional light irradiation device. In this comparative experiment, nitrogen gas was used as the inert gas, and the gas flow rate was the same as 30 l / min.

The experimental results are shown in FIG. As can be seen from FIG. 7, in the case of the light irradiation device of the present invention, the temperature of the window member is 14
It is 7 ° C., which shows that the temperature of the window member can be suppressed to 200 ° C. or lower. On the contrary, in the case of the conventional light irradiation device,
The temperature of the window member is 218 ° C and the temperature of the window member is 200
It was found that the temperature exceeded ℃ and the cooling effect did not increase.

[0032]

As described above, according to the light irradiating device of the first aspect, the ejected inert gas is directly blown to the window member by the inert gas jetting mechanism in the lamp house. The window member can be cooled, and the temperature rise of the window member can be suppressed. Therefore, it is possible to surely process the object to be processed and prevent contaminants from adhering to the window member.

According to the light irradiation device of the second aspect, the inert gas flowing portion of the inert gas ejection mechanism in the lamp house is arranged along the outer periphery of the window member and the direction of the window member. Since the inert gas ejection holes are formed at equal intervals and the inert gas ejected from the inert gas ejection holes is directly blown to the window member, the inert gas ejection holes ejected from the inert gas ejection holes are formed. The gas can extremely reduce the flow distance to the window member, can efficiently and reliably cool the window member, and can suppress the temperature rise of the window member. Therefore, it is possible to surely process the object to be processed and prevent contaminants from adhering to the window member.

According to the third aspect of the light irradiating device, the inert gas flowing portion of the inert gas ejecting mechanism in the lamp house is located away from the window member, and the dielectric of the light reflecting plate. It is arranged so as to be located on the opposite side of the barrier discharge lamp, so that the inert gas ejected from the inert gas ejection hole can be directly blown to the window member through the ventilation hole formed in the light reflection plate. Therefore, the excimer light emitted from the dielectric barrier discharge lamp can be efficiently used, and at the same time, the window member can be cooled and the temperature rise of the window member can be suppressed. Therefore, it is possible to surely process the object to be processed and prevent contaminants from adhering to the window member.

According to the light irradiation device of the fourth aspect, the inert gas flow section of the inert gas ejection mechanism in the lamp house extends toward the space between the partition plate and the window member. An opening for ejecting the inert gas is formed at the end of the inert gas flow section, and the inert gas ejected from this opening is blown between the partition plate and the window member. The active gas first flows into only the narrow space between the window member and the partition plate, and it is difficult for the active gas to flow into the other spaces of the lamp house. Therefore, the window member can be cooled efficiently, The temperature rise can be suppressed. Therefore, it is possible to surely process the object to be processed and prevent contaminants from adhering to the window member.

[Brief description of drawings]

FIG. 1 is an explanatory cross-sectional view showing a configuration of an example of a light irradiation device of the present invention.

FIG. 2 is a sectional view for explaining a dielectric barrier discharge lamp.

FIG. 3 is a perspective view for explaining an inert gas ejection mechanism of the light irradiation device shown in FIG.

FIG. 4 is a cross-sectional view illustrating another example of the light irradiation device of the present invention.

5 is a perspective view illustrating an inert gas ejection mechanism of the light irradiation device shown in FIG.

FIG. 6 is a cross-sectional view illustrating another example of the light irradiation device of the present invention.

FIG. 7 is an experimental data explanatory diagram showing temperatures of window members of the light irradiation device of the present invention and the conventional light irradiation device.

[Explanation of symbols]

1 lamp house 2 Dielectric barrier discharge lamp 3 cooling blocks 42 Light reflector 5 window members 6 Inert gas ejection mechanism 61 Inert gas flow section 62 Inert gas ejection hole

Continued front page    (72) Inventor Masahide Kiyose             1194 Sado, Bessho Town, Himeji City, Hyogo Prefecture Usio             Electric Co., Ltd. (72) Inventor Noriyoshi Hishinuma             1194 Sado, Bessho Town, Himeji City, Hyogo Prefecture Usio             Electric Co., Ltd. F term (reference) 3B116 AA23 BB22 BB90 CD35                 4G075 AA30 AA37 BA05 BA06 BB10                       CA03 CA33 CA63 DA02 EB31                       EB33 EC01 EC09 EC21 FB02                       FB06 FC04 FC11 FC15

Claims (4)

[Claims] 1. A dielectric barrier discharge lamp that generates excimer light by a dielectric barrier discharge, and a lamp house in which the dielectric barrier discharge lamp is housed and a window member for taking out the excimer light is formed. In the light irradiation device that operates in a state in which the inside of the lamp house is replaced with an inert gas, an inert gas ejection mechanism is provided in the lamp house, and the inert gas ejection mechanism is The light irradiation device, wherein the inert gas ejected from the active gas ejection mechanism is directly blown onto the window member. 2. The inert gas jetting mechanism has an inert gas flowing portion through which an inert gas flows, and the inert gas flowing portion is arranged along an outer peripheral edge of the window member. In addition, an inert gas ejection hole is formed in the direction of the window member, and the inert gas ejected from the inert gas ejection hole is directly blown to the window member. The light irradiation device according to claim 1. 3. A light reflection plate for reflecting excimer light generated from the dielectric barrier discharge lamp toward the window member is provided in the casing, and the inert gas ejection mechanism is It has an inert gas flowing part through which an inert gas flows, the inert gas flowing part is at a position separated from the window member, and on the side opposite to the dielectric barrier discharge lamp of the light reflecting plate. And an inert gas ejection hole is formed in the direction of the window member, and the inert gas ejected from the inert gas ejection hole passes through a vent hole formed in the light reflection plate, The light irradiation device according to claim 1, wherein the light irradiation device is directly blown onto the window member. 4. A partition plate that transmits excimer light is disposed in the lamp house between the dielectric barrier discharge lamp and the window member, and the inert gas ejection mechanism has an internal portion. Has an inert gas flow part through which the inert gas flows, the inert gas flow part extends toward between the partition plate and the window member, and at the end of the inert gas flow part. ,
An opening for ejecting an inert gas is formed, and the inert gas ejected from the opening is blown between the partition plate and the window member. The light irradiation device according to.