KR101389786B1 - Dielectric barrier discharge lamp and ultraviolet irradiation device using the same - Google Patents

Abstract

The present invention provides a dielectric barrier barrier discharge lamp for irradiating a vacuum ultraviolet ray, the adhesion of the by-product flying on the discharge tube and the solidification thereof. In order to reduce, the discharge gas for excimer light emission is enclosed inside, and irradiating vacuum ultraviolet-ray downward through the lower wall plate which does not have a front glass and also has a flat surface. In the discharge tube 1 characterized by the above-mentioned, and the semi-open type dielectric barrier discharge lamp provided with the electrodes 2 and 3 inside this discharge tube, the long side surface of the periphery of the lower wall board in this discharge tube The wall surface located in the ()) is composed of a light blocking member 4a that shields at least 50% of ultraviolet rays.

Description

Dielectric barrier discharge lamp and ultraviolet irradiation device using the same {DIELECTRIC BARRIER DISCHARGE LAMP AND ULTRAVIOLET IRRADIATION DEVICE USING THE SAME}

The present invention relates to a dielectric barrier discharge lamp for irradiating vacuum ultraviolet rays, in particular a dielectric barrier discharge lamp having a flat surface on the irradiation side, and a semi-open type using the same. It relates to an ultraviolet irradiation device.

In recent years, dielectric barrier discharge lamps having a flat surface on the irradiation side of the discharge tube are known (Patent Documents 1, 2, 3 and the like). The characteristic is that the in-plane uniformity of the irradiation light is good, and it is not necessary to provide an expensive front glass (corresponding to the window portion 102 of Patent Document 2, Fig. 8) between the discharge tube and the irradiation object. Therefore, there is an advantage that the ultraviolet irradiation device can be manufactured at low cost by connecting with a predetermined power supply device, and the vacuum ultraviolet ray can be directly irradiated to the irradiation object (Patent Document 3). The type which can irradiate a vacuum ultraviolet ray directly to an irradiation object which does not have such a front glass is called a semi-open type ultraviolet irradiation device. Since this type of dielectric barrier discharge lamp has no front glass, various by-products tend to adhere to the discharge tube due to air flow or the like in the lamp house that houses the discharge tube, and crystallization [solidification] 부착 化)] (hereinafter referred to as "solidified matter" or "white powder"), there is a problem that damage the discharge tube. Attachments attached to the outer wall of the discharge tube can be wiped off periodically, but they cannot be removed when solidified to some extent by being exposed to ultraviolet rays for a long time.

It is thought that adhesion of the fly product flying to a discharge tube is "organic silicon compound", such as organic HMDS (hexamethylene disilazane). The white powder adhering to the discharge tube is caused by the decomposition of the organosilicon compound into the siloxane precursor by the ultraviolet light from the discharge tube and deposited on the outer circumferential surface of the discharge tube, and the powder is oxidized and dehydrated by light and heat. It is assumed that the polymerization reaction proceeds to form a firm glassy adhesion film. The adhesion of the powder causes a significant deterioration of the performance of the discharge tube. In addition, when the powder adhered to the discharge tube is dropped by nitrogen gas or the like flowing from the back or side surface of the discharge tube in the irradiation apparatus, the discharge tube may be a source of contamination of the workpiece (object to be irradiated).

Patent Document 1 discloses a front and rear end wall plate by forming a "vacuum ultraviolet ray protection layer" on the inner surface of the front and rear end wall plates and the left and right side wall plates in the discharge vessel of the dielectric barrier discharge lamp having the front and rear sides formed in an extremely long shape. The suppression of deterioration is disclosed (10th to 11th paragraph, etc.). This vacuum ultraviolet protective layer is comprised by absorbing or reflecting at least a vacuum ultraviolet ray (20th short circuit etc.).

Japanese Laid-Open Patent Publication No. 2004-127710 WO2007 / 013602 Japanese Laid-Open Patent Publication No. 2009-183949

The present inventors investigated the relationship between the film thickness of the solidified matter on the light-shielding rate of ultraviolet rays, and found a condition in which the film thickness significantly decreased above a certain value with the light-shielding rate. First, the measuring method of the film thickness of a solidified deposit is demonstrated. 11 is a schematic view of a measuring device. The measuring apparatus 60 is provided with the surface plate 62, the discharge tube fixing stand 63, the micrometer fixing stand 64, and the micrometer 65. In addition, the measuring device 60 includes the discharge tube holder 63 and the micrometer holder 64 on the base plate 62, the micrometer 65 on the micrometer holder 64, and the discharge tube 61 on the discharge tube holder ( Each of them is fixed at 63) so that the measurement position is not shifted. The micrometer 65 used the product made by MITUTOYO (model name: M810-50). As for the film thickness of the solidified deposit, the width | variety of the discharge tube 61 before lighting with no deposit is measured first using the measuring apparatus 60, and then the discharge tube 61 is made into the average roughness 100mW / cm <2>. The width | variety of the discharge tube 61 was measured after lighting for 10 hours, 100 hours, and 1000 hours of predetermined | prescribed light, and finally, it calculated | required the difference between the width before lighting of the discharge tube 61, and the width after lighting. 6 is a graph showing the relationship between the film thickness of the solidified deposit and the shielding rate of ultraviolet rays. The horizontal axis represents the light shielding rate of ultraviolet rays, and the vertical axis represents the film thickness [µm] of the solidified (vitrified) deposit when the light shielding rate is changed from 0 to 100%. Here, 1000 hours of irradiation time is sufficient time for which solidification is considered saturated. Comparing the three graphs of irradiation time of 10 hours, 100 hours, and 1000 hours, it can be seen that the film thickness of the solidified deposit suddenly decreases when the ultraviolet ray shielding rate increases to some extent.

That is, knowledge is obtained that the most effective method for reducing the adhesion and the solidification of fly ash flying to the discharge tube is to shield the product so that the solidification does not proceed as much as possible even if the fly product adheres to the discharge tube. According to this finding, for example, alumina fine particles or silica - alumina mixed fine particles and the like are known as materials for diffusing and reflecting ultraviolet light, and an example is used as a reflective film of a dielectric barrier discharge lamp. none. Therefore, shading becomes incomplete, and the solidification of the adhering by-products progresses, which causes damage to the discharge tube. In particular, nonuniformity tends to be concentrated in the wall surface located in the long side surface of a long direction (front-back direction).

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and in the dielectric barrier discharge lamp for irradiating vacuum ultraviolet rays, the suppression and solidification of adhesion to the wall surface located on the long side surface of the fly-by fly products to the discharge tube It is a technical problem to reduce quantity.

The dielectric barrier discharge lamp according to the present invention includes a discharge tube for enclosing a discharge gas for excimer light emission therein and irradiating ultraviolet rays downward through a lower wall plate having a flat surface, and the outside of the discharge tube. In the dielectric barrier discharge lamp which has an electrode in at least one of the,

The wall surface located in the long side surface of the periphery of the lower wall board in this discharge tube is comprised by the light shielding member which shields at least 50% of ultraviolet-rays, It is characterized by the above-mentioned. From the results in FIG. 6, it can be seen that the solidified deposit starts to decrease from the vicinity where the UV blocking rate exceeds about 50%.

According to the dielectric barrier discharge lamp according to the present invention, it is possible to prevent adhesion of fly-bye flying on the wall surface of the discharge tube made of the light blocking member and to prevent solidification. In particular, the wall surface located on the long side surface (or the four side surface including the short side surface) around the lower wall plate is constituted by the light shielding member, so that the adhering of fly-bye flying on the side surface or the upper surface to the irradiation surface of the discharge tube, The solidification is suppressed and the life of a discharge tube can be improved. If necessary, the upper wall plate may be made of the same light blocking member. The discharge tube which irradiates a vacuum ultraviolet ray adheres to the wall surface much, and can produce a big effect.

In addition, the "discharge tube which irradiates an ultraviolet-ray downwardly through a lower wall board" defines the shape of the discharge tube which is presupposed to implement this invention, for example, "the longest before and after, and the top and bottom are the shortest. And a substantially rectangular box shape in which the substantially flat upper and lower wall plates facing each other from above and below each other have a shape substantially parallel to each other, or &quot; a flat cylinder by breaking down part of the arc of the outer circumferential wall in an elongated cylinder. And a lower wall plate having a flat portion serving as a substitute for the windshield, such as having an arcuate curved portion and a flat plate portion connecting the edges of the circular arcs on the curved portion. UV radiation is applied through.

The higher the light shielding rate of the light shielding member constituting the wall surface of the discharge tube, the more preferable. When the light shielding rate is 70% or more, for example, 90% or more, the relative film thickness of the solidified deposit is solidified and the solidification of the fly product is 0. Can be suppressed to 5% or less when irradiated with 1000 hours.

Here, the output intensity I of the light transmitted through the film having the film thickness t uses the input strength I ₀ , the absorption coefficient α, and the film thickness t,

^{_{I = I 0 · e -αt ····}} ( formula 1)

[Where e is the base of natural algebra]

. Since the transmittance is expressed as I / I _0, the light-shielding rate is obtained by _{(1-I / I 0)} .

In general, since "shielding" means blocking light, it may occur when "shielding" is realized by "reflection", "absorption", or "refraction". However, in the present invention, as a result, the effect of preventing adhesion or solidification of fly ashes is provided unless the vacuum ultraviolet ray can block 50% or more (more preferably 70% or more, most preferably 90% or more). Attention should be paid to what is not possible. In addition, a "light-shielding member" is a member which blocks light, and may be comprised with one type of material, and may be comprised with two or more types of materials.

In addition, the dielectric barrier discharge lamp according to the present invention includes a discharge tube for enclosing a discharge gas for excimer light emission therein and irradiating ultraviolet rays downwardly through a lower wall plate having a flat surface, and at least one of the outside of the discharge tube. A dielectric barrier discharge lamp provided with an electrode,

The wall surface located in the long side surface of the lower wall plate in this discharge tube is comprised by the light shielding member which light-shields so that the average illuminance of the ultraviolet-ray radiated | emitted from the said wall surface to the exterior of a discharge tube may be 50 mW / cm <2> or less at the time of the said lamp lighting. It is characterized by that. From the results in Fig. 6, the solidified deposit started to decrease from the vicinity where the UV blocking rate exceeded about 50%, i.e., the vicinity of the average illuminance of the ultraviolet rays radiated to the outside of the discharge tube was 50 mW / cm 2 or less. Able to know. That is, it can be seen that the decrease is started from the vicinity where the average illuminance of the ultraviolet rays radiated to the outside of the discharge tube is 50 mW / cm 2 or less. More preferably, it is preferable to light it so that the average illuminance of the ultraviolet-ray radiated | emitted to the exterior of a discharge tube may be 30 mW / cm <2> or less, More preferably, it should just be comprised by the light shielding member which shields so that it may become 10 mW / cm <2> or less. In addition, an average roughness is an average value at the time of measuring five surface roughnesses of a discharge tube. As described later, the average roughness of the side wall surface can be calculated based on the average roughness of the lower wall plate and the light shielding ratio of the side wall surface.

A method of lighting a dielectric barrier discharge lamp according to the present invention includes a discharge tube for enclosing a discharge gas for excimer light emission therein and irradiating ultraviolet rays downward through a lower wall plate having a flat surface, and at least one of the outside of the discharge tube. As a method of lighting a dielectric barrier discharge lamp having an electrode,

The average illuminance of the ultraviolet rays radiated to the outside of the discharge tube from the wall surface located on the long side of the lower wall plate in the discharge tube is characterized by being 50 mW / cm 2 or less. From the results in FIG. 6, it can be seen that the solidified deposit starts to decrease from the vicinity of the ultraviolet shielding rate exceeding about 50%, i.e., the vicinity of the average illuminance of the ultraviolet rays radiated to the outside of the discharge tube is 50 mW / cm 2 or less. . More preferably, it is preferable to light it so that the average illuminance of the ultraviolet-ray radiated | emitted to the exterior of a discharge tube may be 30 mW / cm <2> or less, More preferably, it is preferable to light it so that it may become 10 mW / cm <2> or less.

When the illuminance of the light irradiated onto the object to be irradiated may be reduced, or when irradiating the irradiated object after condensing the light irradiated from the lower wall plate, by lowering the illuminance as the entire discharge lamp, the long side surface around the lower wall plate The average illuminance of the ultraviolet rays radiated to the outside of the discharge tube from the wall surface on which it is located can be 50 mW / cm <2> or less. Further, in addition to lowering the illuminance of the entire discharge lamp, by forming the wall surface positioned on the long side surface around the lower wall plate with the light shielding member, ultraviolet rays radiated to the outside of the discharge tube from the wall surface located on the long side surface around the lower wall plate. You may light so that the average illuminance may be 50 mW / cm <2> or less.

In the dielectric barrier discharge lamp according to the present invention, a member including a transparent member and a light shielding film can be used as the light shielding member. The light shielding film should just be arrange | positioned in the position which can shield the ultraviolet-ray irradiated to the outside through a transparent member, For example, what is necessary is just the structure which provided the light shielding film in the surface of the transparent member. A synthetic quartz plate, a fused quartz plate, etc. can be used for a transparent member. After the entire discharge tube is constituted of the same transparent member such as a synthetic quartz plate, it is preferable to form a light shielding film on the wall surface located on the long side surface of the lower wall plate in the discharge tube, but the lower wall plate and the transparent member are necessarily the same member. Need not be Thus, by configuring a light shielding member with a transparent member and a light shielding film, physical properties, such as the intensity | strength of a discharge tube, can be easily adjusted to the transparent member side, and the light shielding property with respect to an ultraviolet-ray can be easily adjusted by the light shielding film side.

Moreover, as this transparent member, the baking material of the slurry (cloud liquid) which made the fine particle of the oxide which has ultraviolet light-shielding property clouded in the solvent can be used. This light shielding film may be formed inside the discharge tube or may be formed outside. It is preferable that the primary particle diameter of these microparticles | fine-particles is 3 micrometers or less. By using fine particles having a small particle diameter as the material of the light shielding film, a light shielding film having densely arranged particles with less space between particles can be formed as compared with the case where a large particle diameter is used. As a result, the probability that the ultraviolet rays leave the space between the particles is reduced, so that the ultraviolet ray blocking rate can be easily increased. In addition, it is possible to reduce the nonuniformity of the overall shading rate.

Alcohols (ethanol, isopropyl alcohol, n-butanol, etc.), xylene, toluene, etc. can be used for a solvent. Moreover, since ultrafine particles are disperse | distributed in a solvent, what is necessary is just to add surfactant, such as a polycarboxylic acid partial alkyl ester type, a polyether type, and a polyhydric alcohol ester type.

Moreover, Preferably, the primary particle diameter of the microparticles | fine-particles of an oxide shall be 10-100 nm. If the particle diameter of the fine particles is larger than 100 nm, the dispersibility in the slurry may deteriorate, resulting in a non-uniform light shielding film. In addition, since the space between the particles becomes wider, the ultraviolet ray shielding rate is lowered. When the particle diameter of the fine particles is smaller than 10 nm, the surface energy of the particles is high, and the particles are aggregated to precipitate in the slurry.

In addition, preferably, the fine particles of the oxide may contain yttrium oxide (Y ₂ O ₃ ) as a main component. Yttria has ultraviolet absorbency and is an insulator. Therefore, in the case where the light shielding film is formed inside the discharge tube, it is possible to form a light shielding film having ultraviolet light shielding properties and not causing abnormal discharge in the discharge tube during discharge, and when the light shielding film is formed outside the discharge tube. It is not necessary to worry about the electrical contact with the electrodes provided on the outside of the discharge tube. In addition to yttrium oxide, ultrafine particles containing zinc oxide (ZnO) or titanium oxide (TiO ₂ ) coated with silica (SiO ₂ ) as a main component may be used. These materials are useful for vacuum ultraviolet light having 172 nm as the center wavelength when xenon gas is used as the discharge gas.

Moreover, it is preferable that the light shielding film used for the dielectric barrier discharge lamp which concerns on this invention shields mainly by ultraviolet absorption. This is because the light shielding film can be thinned. Ultraviolet reflectivity is highly dependent on the film thickness as compared with ultraviolet absorbency. Therefore, in order to make the light shielding rate 50% or more by the light shielding film which has ultraviolet reflectivity, it is necessary to be a thicker film, ie, a thick film compared with the case where the light shielding film which has ultraviolet absorbance is used. In particular, when the shading rate is 70% or more and 90% or more, the difference is remarkable. When the light shielding film of a thick film | membrane is formed in the wall surface located in the long side surface periphery of a lower wall board, as the heat insulation effect of a discharge tube rises, the temperature in a discharge tube rises at the time of lamp lighting, and light emission efficiency will fall. In addition, the thicker the film, the more easily the crack occurs in the light shielding film when the lamp is turned on due to the difference in thermal expansion coefficient between the transparent member and the light shielding film. Therefore, Preferably, the film thickness of a light shielding film should just be 10 micrometers or less. In addition, the "light-shielding mainly by ultraviolet absorbency" shown here is a case where the light-shielding rate by "absorption" is larger than the light-shielding rate by "reflection" or "refraction." As a material mainly shielded by ultraviolet absorption, yttrium oxide (Y ₂ O ₃ ), zinc oxide (ZnO), zirconium oxide (ZrO ₂ ), etc. may be mentioned. do.

The lower wall plate may be made of a synthetic quartz plate, and four side surfaces (both front and rear and left and right wall surfaces) or the upper wall plate of the lower wall plate may be made of a molten quartz plate. Since the molten quartz plate contains more impurities than the synthetic quartz, the light-shielding rate with respect to vacuum ultraviolet rays is 70% or more, and since welding to synthetic quartz is also easy by heating, it is suitable as a light-shielding member.

Alternatively, the light-emitting tube itself is composed entirely of a synthetic quartz plate, but when the four side surfaces (both front and rear and left and right side walls) around the lower wall plate or the surface of the upper wall plate have a light shielding rate of 70% or more, for example. You may roughen it until. Compared with the roughening surface, the surface roughness is increased compared to the mirror surface wall surface, chemically eroded by contacting hydrofluoric acid and the like to roughen the surface, and spraying fine particles such as sand blast. There is a method of roughening the surface by physically losing the mirror state.

The dielectric barrier discharge lamp according to the present invention can be an ultraviolet irradiation device by using a power supply device that outputs electric power for generating excimer light emission and a lead wire for supplying power from the power supply device. When irradiating the irradiated object in which the layer of the organosilicon compound is formed on the irradiated surface by such an ultraviolet irradiating apparatus, in addition to the organosilicon compound originally suspended in air | atmosphere, organosilicon also from the irradiated object Since the compound is flying, the by-products are more likely to fly on the wall surface of the discharge tube. Therefore, when using the irradiated control material in which the layer of the organosilicon compound was formed in a part of a to-be-irradiated surface, the effect of suppressing adhering of a scattering product or preventing solidification becomes remarkable. And an organosilicon compound may be used as an intermediate | middle layer for improving the adhesiveness of a to-be-irradiated object and a resist, when performing a resist with respect to a to-be-irradiated object.

According to the dielectric barrier discharge lamp according to the present invention, since the wall surface positioned on the long side or the four side surface of the lower wall plate in the discharge tube is composed of a light blocking member that shields at least 50% of ultraviolet rays, the discharge tube constituted by the light blocking member. It is possible to prevent adhesion of the fly-bye adhering to the wall surface of the substrate and to prevent solidification.

FIG. 1 is a perspective view showing a first embodiment in which a long central portion of a dielectric barrier discharge lamp is omitted.
FIG. 2 shows a first embodiment, (a) is a cross-sectional view of the discharge tube 1a of FIG. 1 cut from the long central axis and viewed from the lateral direction, and (b) is a long direction of the dielectric barrier discharge lamp. Sectional drawing and (c) is sectional drawing of the B-B line | wire of (a).
(A) and (b) of FIG. 3 form an ultraviolet light shielding film in the inner wall surface which is located in the four side surface of the periphery of the lower wall board in the discharge tube 1 of the dielectric barrier discharge lamp shown in FIG. 1 and FIG. It is a figure which shows the state.
4A and 4B show a second embodiment of the present invention and a modification thereof, and are sectional views in the long direction of the dielectric barrier discharge lamp.
FIG. 5 is a perspective view of a third embodiment of the present invention, in which a long central portion of the dielectric barrier discharge lamp is omitted.
6 is a graph showing the relationship between the film thickness of the solidified deposit and the shielding rate of ultraviolet rays.
Fig. 7 is a side sectional view of the ultraviolet irradiation device of the fourth embodiment.
(A) is sectional drawing in the surface perpendicular | vertical to the longitudinal direction of the discharge tube of the ultraviolet irradiation device of FIG. 7 as a barrier discharge lamp of 4th Example, (b) is a barrier of 4th Example shown to (a). It is a 1st modification of a discharge lamp.
Fig. 9 is a second modification of the barrier discharge lamp of the fourth embodiment shown in Fig. 8A.
10 is a schematic diagram of an experimental apparatus.
11 is a schematic diagram of a measuring device.

Hereinafter, each embodiment of the present invention will be described with reference to the drawings. The same reference numerals are used for the same or the same type of members or only the subscripts are used, and duplicate descriptions are omitted. However, descriptions of the embodiments are interpreted for the purpose of understanding the technical spirit of the present invention. It is not limited to description of an Example and interpreted.

(Embodiment 1)

1 and 2 illustrate a first embodiment of the present invention, in which a long central portion of the dielectric barrier discharge lamp is omitted. FIG. 2A is a cross-sectional view of the discharge tube 1a of FIG. 1 cut from the long central axis and viewed from the side surface. (B) is sectional drawing in the elongate direction of a dielectric barrier discharge lamp, ie, the AA cross-sectional view of FIG. 2 (a), (c) is B-B of FIG. Line cross section.

The discharge tube 1 of this dielectric barrier discharge lamp has a substantially rectangular box shape and is formed in both ends of the long glass tube 1a made of synthetic quartz, and has a shape substantially the same as the cross section of the square tube 1a. It is formed by welding and blocking the front and rear end wall plates 1b and 1b made of glass, respectively. Xenon gas is enclosed inside. The square tube 1a is a rectangular tube whose height in the vertical direction of the cross section is several tens of mm, and the width in the left and right directions is several tens of mm, and the length in the front-rear direction is, for example, 1 m or more. Therefore, this square tube 1a is comprised from the flat upper and lower wall boards which face each other in the up-and-down direction, and the flat left and right side wall boards which face each other in the left-right direction. Chip pipes 1c and 1c are projected in advance on the front and rear end wall plates 1b and 1b welded to the openings at both ends of the square tube 1a, respectively. Each chip tube 1c is a pipe material made of fused quartz glass welded to protrude outward from the outer surface of the front and rear end wall plates 1b, and the inside of the tube is formed in a preliminary central portion of the front and rear end wall plates 1b. Installed through the ball. The discharge vessel 1 is formed on the outer surface of the upper and lower wall plates of the square tubes 1a on the outer surface of the upper and lower wall plates of the electrodes 2 and 3 before or after welding the front and rear wall plates 1b and 1b to the openings at both ends of the square tubes 1a. A thin film is formed. The electrode 2 covers almost the entire surface of the upper surface of the upper wall plate of each tube 1a except for the uncoated portion for the sensor for inspecting the intensity of the vacuum ultraviolet rays emitted by the dielectric barrier discharge lamp. To be formed. In addition, the electrode 3 is formed into a pattern of a mesh shape on almost the entire surface of the lower surface of the lower wall plate of the square tube 1a.

The ultraviolet light shielding film 4a obtained by baking the slurry containing yttrium oxide (Y ₂ O ₃ ) is provided on all four inner side surfaces of the discharge tube 1 around the lower wall plate. This film can shield 172 nm of vacuum ultraviolet rays, and the light shielding rate can be adjusted according to the film thickness. Then, the ultraviolet irradiation device is constituted by connecting with the power supply device, and the dielectric barrier discharge lamp is turned on by applying a predetermined power to the electrode through the lead wire, and through this flat lower wall plate, as shown in FIGS. 2A and 2B. In (c) of FIG. 2, in the direction of an arrow, 172 nm of vacuum ultraviolet rays are irradiated below the paper surface perpendicularly.

(A) and (b) of FIG. 3 form an ultraviolet light shielding film in the inner wall surface which is located in the four side surface of the periphery of the lower wall board in the discharge tube 1 of the dielectric barrier discharge lamp shown in FIG. 1 and FIG. It shows the shape. First, the slurry containing yttrium oxide (Y ₂ O ₃ ) is injected from the chip tube 1c so as to be inclined such that the square tube 1a is lowered as shown in the figure, and dried. This operation is performed on both side surfaces and front and rear wall plates, and then fired at 500 ° C. for 30 minutes. Thereafter, the gas is discharged from the chip tube 1c and a discharge gas (for example, xenon gas) is injected to fill the discharge gas therein. And the tip part of both chip tubes 1c is melt-sealed, and the inside is sealed. Thereafter, a metal for electrode is deposited and patterned, and finally, magnesium fluoride (MgF ₂ ) is deposited to form a coating film for protecting the electrode, thereby completing the discharge tube. Then, YAP10WT% -X480 (manufactured by CIK Nanotech Co., Ltd.) containing 10% by weight of yttrium oxide having a primary particle diameter of 33 nm is used as a stock solution, and the diluted solution of this stock solution with n-butanol is used as a slurry. By changing the degree of dilution, the light shielding rate of the ultraviolet light shielding film can be changed.

-Experiment-

Here, according to the above-mentioned manufacturing method, six kinds of discharge tubes differing only in the film thickness of yttrium oxide were started, and the adhesion amount and degree of solidification of the solidified solidified matter (powder) adhered to the tube wall were examined. The experimental conditions are as follows.

(1) Disclosure lamp

A. Start lamp 1... Side UV Shading (Yttrium Oxide) Formation

                 Shading rate 99% (there is no dilution)

                 Average roughness 101mW / cm2 from lower wall plate

                 Average roughness from the side wall surface 1 mW / cm 2

B. Start lamp 2... Side UV Shading (Yttrium Oxide) Formation

                 90% shading (4-fold dilution)

                 Average roughness 98mW / cm2 from lower wall plate

                 Average roughness 10 mW / cm 2 from the side wall

C. start lamp 3... Side UV Shading (Yttrium Oxide) Formation

                 Shading 71% (6-fold dilution)

                 Average roughness 101mW / cm2 from lower wall plate

                 Average roughness from the side wall surface 29 mW / cm 2

D. start lamp 4... Side UV Shading (Yttrium Oxide) Formation

                 Shading rate 56% (10-fold dilution)

                 Average roughness 107mW / cm2 from lower wallboard

                 Average roughness 47mW / ㎠ from side wall surface

E. start lamp 5... Side UV Shading (Yttrium Oxide) Formation

                 30% shading (20-fold dilution)

                 Average roughness 104mW / cm2 from lower wall plate

                 Average roughness from the side wall surface 73 mW / cm 2

F. Conventional Products… Shading rate 0%

                 Average roughness 109mW / cm2 from lower wallboard

                 Average roughness 109mW / ㎠ from side wall surface

(2) Power supply: Lamp applied peak voltage of 3.8kV, driving frequency 70kHz (approximate square wave)

(3) irradiation apparatus:

10 shows a schematic diagram of an experimental apparatus. And the arrow shows the flow direction of a fluid. As shown in FIG. 10, the irradiation mechanism 50 stores the dummy lamp 53 and the punching metal plate in the container 56 by using any one of the six types of publication lamps 54. ), And the nitrogen gas containing HMDS from the bubbling vessel 51 flows air A1 and A2 from the horizontal side of the vessel 56, respectively, and the exhaust gas after irradiation. It is configured to discharge E. The bubbling vessel 51 stores the HMDS 52 therein. Nitrogen gas containing HMDS is obtained by flowing nitrogen gas N (N ₂ ) into a nozzle into the HMDS 52, and flowing it into the irradiation mechanism 50 through a pipe.

At this time, the content of the HMDS refers to the size of the bubbles of nitrogen gas that are allowed to pass through the HMDS 52 in a state where the temperature of the bubbling vessel 51 is kept constant at 20 ° C, and the rising distance of the bubbles, that is, Nitrogen gas is adjusted according to the distance from the tip of the nozzle which flows into the HMDS 52 to the liquid level. Since HMDS 52 decreases with the inflow amount of nitrogen gas N, it replenishes suitably until an experiment is complete.

(4) HMDS: Always supply

(5) Total nitrogen amount: 50L / min

(6) lighting time: 1000 hours

(7) roughness measurement:

 By the ultraviolet illuminometer (UIT150 / VUV-S172, product made by Ushio Electric Co., Ltd.), five surface roughnesses of a discharge tube lower wall board are measured, and the average value is made into the average illuminance. In that case, a measurement location divides the area | region (region | region equivalent to discharge space) which a pair of electrodes oppose into 5 equally in a long direction, and makes it the center vicinity. Therefore, the measurement points are set at substantially equal intervals.

Further, in this case, the average roughness of the side wall is calculated by using the shading ratio (1-I / I ₀₎ of the average roughness and the sidewall face of the lower wall plate. By side the light blocking ratio of the wall surface (1-I / I ₀₎ when it is displayed, the side the transmittance of the wall, which is multiplied by the average illuminance E and the transmittance of the side wall I / I ₀ of the lower wall plate, so I / I _0, Average roughness of the side wall surface is obtained.

-result-

Table 1 has shown the experiment result after 1000 hours. The start lamp 2 which light-shielded the ultraviolet-ray of side by side by 90% had little powder adhesion amount, the vitrification film thickness at that time was 15 micrometers, and vitrification (solidification) was seen slightly. Although the starting lamp 3 which shielded the ultraviolet-ray of the side surface by 71% had small amount of powder adhesion, the vitrification film thickness at that time was 69 micrometers, and vitrification was seen a little. The start lamp 4 which shielded 56% of the ultraviolet rays from the side surface had a slightly larger amount of powder adhered than the start lamp 3, and the vitrification film thickness at that time was 159 µm. On the other hand, the start lamp 5 which shielded 30% of the ultraviolet rays on the side face had a larger amount of powder deposit than the start lamp 4, and the vitrification film thickness at that time was 306 µm. Moreover, the conventional lamp which did not shield the ultraviolet-ray of the side surface has very much amount of powder adhesion, and the vitrification film thickness at that time was 300 micrometers. From these facts, the following became clear.

1. Shading on the side has the effect of reducing the amount of powder deposited.

2. The light shielding of 56% or more of the side surface has an effect of preventing vitrification (solidification). From the tendency, it is recognized that it is effective at 50% or more. It is remarkable at 71% or higher and more pronounced at 90% or higher. This result is in good agreement with the graph of FIG. 6.

Thus, even if an organosilicon compound adheres to the side surface of a discharge tube, it can prevent a chemical reaction from advancing from it by shielding an ultraviolet-ray, and can suppress a firm glassy deposit. The smaller amount of the deposit itself is considered to be due to the impossibility of the powder itself in the space near the side surface.

(Second Embodiment)

4A and 4B show a second embodiment of the present invention and a modification thereof, and are sectional views in the long direction of the dielectric barrier discharge lamp. In the first embodiment, the embodiment in which the light shielding film is formed on the inner wall surface located on the four side surfaces of the lower wall plate is described. However, as shown in FIG. 4, the ultraviolet light shielding film 4b may be provided on the outer circumference of the discharge tube. Although not shown, a light shielding film is also provided in the front and rear end surfaces. When using the sintered compact of a metal oxide as a light shielding film, it is preferable to perform the application | coating, drying, and baking process of a light shielding film before an electrode formation process. It is because there exists a possibility that the problem, such as deterioration of an electrode, may arise when a baking process is performed after electrode pattern formation. However, if the heat treatment step is unnecessary, a light shielding film may be formed on the side surface portion of the discharge tube after electrode formation. It is considered that the degree of freedom in the manufacturing process increases and the range of material selection of the light shielding film is wider than that in the case of forming the light shielding film inside the discharge tube.

―Modification example―

Alternatively, as shown in Fig. 4B, the inner wall surface itself located on the four side surfaces of the lower wall plate may be formed of a light shielding member, and may be bonded to the upper and lower wall plates by welding or glass frit. do. In this case, the lower wall plate may be composed of a synthetic quartz plate, while the four side surfaces (both front and rear and left and right wall surfaces) or the upper wall plate around the lower wall plate may be composed of the molten quartz plate 4c. Molten quartz is a material obtained by melting natural quartz (natural silica) to solidify it into a plate shape, and has a high shading rate of 70% or more with respect to vacuum ultraviolet rays for containing a large amount of impurities, and also facilitates welding with synthetic quartz by heating. Because. An equivalent effect can be obtained even if a ceramic plate is used in place of natural quartz as the light blocking member. In this case, since it cannot weld with synthetic quartz, glass frit can be used as a bonding agent.

By such a structure, even if the organosilicon compound adheres to the side surface of a discharge tube, by blocking ultraviolet rays, a chemical reaction does not progress from it as much as possible, and formation of a rigid glassy deposit can be suppressed.

(Third Embodiment)

FIG. 5 is a perspective view of a third embodiment of the present invention, in which a long central portion of the dielectric barrier discharge lamp is omitted. FIG. 5A is a cross-sectional view of the discharge tube 1a of FIG. 1 cut out from a long central axis and viewed from the lateral direction. FIG. 5B is a cross-sectional view in the long direction of the dielectric barrier discharge lamp, that is, the A-A cross-sectional view of FIG. 5A, and FIG. 5C is B-B of FIG. 2A. Line cross section.

In the third embodiment, the light-emitting tube itself is composed entirely of a synthetic quartz plate, but the light shielding rate is applied to the four side surfaces (both front and rear and left and right wall surfaces) or the surface of the upper wall plate around the flat lower wall plate, for example. Roughen until 70% or more. Roughening is to increase the surface roughness of the wall surface in the mirror state, and the roughening method is, for example, by chemically eroding by contacting hydrofluoric acid and roughening the surface, and physically by spraying fine particles such as sand blast There is a method of roughening the surface by losing the mirror state.

As shown in Fig. 5A, a rough surface 4d having an ultraviolet light shielding action is formed on four side surfaces (both wall surfaces in the front-rear direction and the left-right direction) around the lower wall plate. In the method of bringing the hydrofluoric acid into contact with each other, the hydrofluoric acid is injected into the discharge tube from the chip tube 1c in the same manner as in the slurry injection process described above in the first embodiment, and the four side surfaces (front and rear directions and the left and right of the lower wall plate) are injected. Both sides of the wall surface) or the upper wall plate may be dissolved with hydrofluoric acid to roughen the surface. Even in this manner, even when the vacuum ultraviolet ray is not exposed from the side surface portion and the organosilicon compound adheres to the side surface of the discharge tube, it is possible to suppress the solid glass deposit by preventing the chemical reaction from proceeding as much as possible by shielding the ultraviolet ray.

Instead of chemical treatment using hydrofluoric acid, a physical treatment may be used to form the rough surface 4d having the ultraviolet light shielding effect.

(Fourth Embodiment)

In the first to third embodiments described above, the dielectric barrier discharge lamp and the ultraviolet irradiation device using the same have been described in which all discharge tube shapes are substantially rectangular box-shaped and have long rectangular tubes, but the present invention is limited to such shapes. It is possible to apply any of the semi-open type ultraviolet irradiation apparatuses, wherein the ultraviolet rays are irradiated downwardly through the lower wall plate which is not provided with the front glass and has a flat surface. In the fourth embodiment, another embodiment of the present invention will be described.

In FIG.7 and FIG.8, FIG.7 has shown the sectional side view of the ultraviolet irradiation device, and FIG.8 has shown sectional drawing in the surface perpendicular | vertical to the longitudinal direction of the discharge tube of the ultraviolet irradiation device of FIG. In the ultraviolet irradiation device 10 shown in FIG. 7, the barrier discharge lamp 11 and the AC power supply device 22 are connected through the lead wires 20 and 21. The discharge tube 12 of the barrier discharge lamp 11 has a double tube structure consisting of an exterior portion 13 and an inner tube portion 14, and an inner tube portion inserted into the exterior portion 13 and the exterior portion 13 ( 14).

As shown in FIG. 8, the exterior part 13 is an arcuate curved part 15 which made a part of the circular arc of the outer circumferential wall flatten | deflated in the elongate cylinder, and the circular arc part in this curved part 15. A flat plate portion 16 (lower wall plate) for connecting both edges is provided. Vacuum ultraviolet ray is irradiated through this flat part 16. A ball is attached to the corner portion 15A where the curved portion 15 and the flat portion 16 are joined. On the other hand, the inner tube portion 14 is a cylinder having a diameter smaller than that of the outer portion 13, and the outer tube portion 13 and the inner tube portion disposed on the inner wall surface of the flat portion 16 at a lateral center position ( 14 is joined to each other at both ends, and discharge gas, such as xenon gas, is enclosed in the discharge space 17 enclosed by both.

Electrodes 18 and 19 are provided outside the discharge tube 12. The upper electrode 18 of these pair of electrodes consists of a metal film fixed to the outer wall surface of the curved part in the exterior part 13. As shown in FIG. And as a material of the upper electrode 18, it is preferable to use what reflects an ultraviolet-ray. As the material of such a material, aluminum can be used, for example. As for the film thickness of the upper electrode 18, it is preferable that the reflectance is high, It is preferable that it is the film thickness which does not transmit an ultraviolet-ray to the exterior by shielding at least 70% or more, More preferably, 90% or more. On the other hand, the lower electrode 19 consists of a nickel wire, and is inserted in the inside of the inner tube part 14 over almost the entire length. The lower electrode 19 is provided at an equidistant position from each point on the upper electrode 18. One end of the lead wires 20 and 21 is connected to these electrodes 18 and 19, and the other end of these lead wires 20 and 21 is connected to an AC power supply device.

As shown in Fig. 8 (a), it has the inner wall surface of the four-way located at the four sides of the periphery of the flat portion 16 in the exterior unit 13, a slurry containing yttrium oxide (Y ₂ O ₃₎ Ultraviolet light shielding film 4e obtained by firing is provided. This film can shield 172 nm of vacuum ultraviolet rays, and the light shielding rate can be adjusted according to the film thickness.

The ultraviolet light shielding film 4e is preferably composed of a light blocking member that shields at least 50% or more, more preferably 70% or more, and most preferably 90% or more. In addition, as illustrated in FIG. 8, it is preferable to form an ultraviolet light shielding film so as to partially overlap the end portion 18A of the upper electrode 18 which also functions as an ultraviolet reflecting film. In this way, ultraviolet rays leaking out of the exterior portion 13 can be reliably shielded by the ultraviolet reflecting film 4e, and solidification proceeds as much as possible therefrom even if fly products adhere to the surface of the exterior portion 13. You can prevent it. This point is the same also in the following modified examples 1 and 2.

-Modification example 1-

FIG. 8B shows a first modification of the barrier discharge lamp of the fourth embodiment shown in FIG. 8A. As shown in FIG. 8, the barrier discharge lamp 30 has a structure of the discharge tube 31 having a single tube structure without an inner tube portion, and the upper electrode 34 has an arcuate shape of the discharge tube 31. It is provided on the curved part 32, and the lower electrode 35 is provided in the flat part 33 (lower wall board). On all four inner side surfaces of the flat portion 33, an ultraviolet light shielding film 4f obtained by firing a slurry containing yttrium oxide (Y ₂ O ₃ ) is provided. This film can shield 172 nm of vacuum ultraviolet rays, and the light shielding rate can be adjusted according to the film thickness.

―Modification example 2―

Fig. 9 shows a second modification of the barrier discharge lamp of the fourth embodiment shown in Fig. 8A. As shown in FIG. 9, this barrier discharge lamp 40 has the structure of the discharge tube 41 in the structure of the double tube which consists of the exterior part 42 and the inner tube part 43, and the upper electrode 47 is a discharge tube. It is provided on the arcuate curved part 44 of 41, and the lower electrode 48 is inserted in the inner pipe | tube part 14 over almost the entire length. The lower electrode 48 is provided at an equidistant position from each point on the upper electrode 47. One end of the lead wires 20 and 21 is connected to these electrodes 47 and 48, and the other end of these lead wires 20 and 21 is connected to an AC power supply device. Moreover, the auxiliary electrode 49 is provided in the outer surface of the exterior part in the flat part 45 (lower wall board) of the discharge tube 41 over almost the whole surface. This auxiliary electrode 49 assists in main discharge between the pair of electrodes 47 and 48. The auxiliary electrode 49 is formed in a mesh type so as not to block light emitted from the inside of the discharge tube 41 as much as possible, and is provided over the entire length of the discharge tube 41 in the longitudinal direction.

Then, the inner wall surface of the four-way located at the four sides of the periphery of the flat portion 45, the ultraviolet light shielding film (4g) which is obtained by sintering a slurry containing yttrium oxide (Y ₂ O ₃₎ is provided. This film can shield 172 nm of vacuum ultraviolet rays, and the light shielding rate can be adjusted according to the film thickness.

As described above, the dielectric barrier discharge lamp according to the present invention is not limited to a substantially rectangular box-shaped discharge tube in the strict sense, as long as it is a semi-open type ultraviolet irradiation device that does not require the front glass, but also applies to the discharge tube having an arcuate cross section. can do. In this case, the structure of the discharge tube may be provided regardless of the double tube structure or the single tube structure, and in the case of the double tube structure, an auxiliary electrode may be provided.

[Industrial Availability]

Since the dielectric barrier discharge lamp according to the present invention is a substantially rectangular box-type dielectric barrier discharge lamp that does not require a front glass, not only can the manufacturing cost be suppressed, but also nonuniformity is concentrated on both side walls in the long direction (front and rear direction). Industrial applicability is large in that it is possible to prevent the use of the product and to increase the life of the discharge tube.

1: discharge tube
2: upper electrode
3: lower electrode
4: shading member
4a: ultraviolet light shielding film
4b: ultraviolet light shielding film
4c: fused quartz plate
4d: rough surface with ultraviolet light blocking
4e ~ 4g: UV light shield
10: UV irradiation device
11, 30, 40: barrier discharge lamp
12, 31, 41: discharge tube
13, 42: exterior
14, 43: inner tube
15, 32: arched surface
16, 33, 45: flat part
17: discharge space
18, 34, 47: upper electrode
19, 35, 48: lower electrode
20, 21: lead wire
22: AC power supply
49: auxiliary electrode
50: probe apparatus
51: bubbling vessel
52: HMDS (hexamethylenedisilazane)
53: dummy substrate (SUS)
54: disclosure lamp
55: punching metal plate
60: measuring device
61: discharge tube
62: surface plate
63: discharge tube holder
64: micrometer holder
65: micrometer
A1, A2: Air
N: nitrogen gas
E: exhaust gas

Claims (20)

A discharge tube for enclosing a discharge gas for emitting excimer light and irradiating ultraviolet rays downward through a lower wall plate having a flat surface, and an electrode on at least one of the outside of the discharge tube In a dielectric barrier discharge lamp,
The wall surface located in the long side surface of the lower wall board in the said discharge tube is a dielectric barrier discharge lamp comprised from the light shielding member which has the ultraviolet absorbing property which shields the said ultraviolet-ray at least 50% or more. The method of claim 1,
And the light blocking member has a light blocking rate of 70% or more. The method of claim 1,
And the light blocking member has a light blocking rate of 90% or more. A dielectric barrier discharge lamp comprising a discharge tube for enclosing a discharge gas for emitting excimer light and irradiating ultraviolet rays downward through a lower wall plate having a flat surface, and an electrode on at least one of the outside of the discharge tube.
The wall surface located on the long side surface of the lower wall plate in the discharge tube is ultraviolet absorbing so that the average illuminance of the ultraviolet rays radiated from the wall surface to the outside of the discharge tube when the lamp is turned on is 50 mW / cm 2 or less. A dielectric barrier discharge lamp composed of a light blocking member having a. 5. The method of claim 4,
The light blocking member which shields the wall surface located in the long side surface of the lower wall board in the said discharge tube so that the average illuminance of the said ultraviolet-ray radiated | emitted from the said wall surface to the exterior of the said discharge tube may be 30 mW / cm <2> or less at the time of the said lamp lighting. Consisting of, dielectric barrier discharge lamp. 5. The method of claim 4,
The light blocking member which shields the wall surface located in the long side surface of the lower wall board in the said discharge tube so that the average illuminance of the said ultraviolet-ray radiated | emitted from the said wall surface to the exterior of the said discharge tube may be 10 mW / cm <2> or less at the time of the said lamp lighting. Consisting of, dielectric barrier discharge lamp. In the lighting method of the dielectric barrier discharge lamp of Claim 1,
A method for lighting a dielectric barrier discharge lamp, wherein the average illuminance of the ultraviolet rays radiated to the outside of the discharge tube from the side surface positioned on the long side surface of the lower wall plate in the discharge tube is 50 mW / cm 2 or less. 8. The method of claim 7,
The average illuminance of the ultraviolet-ray radiated | emitted to the exterior of the said discharge tube from the side surface located in the long side surface surrounding the lower wall board in the said discharge tube is 30 mW / cm <2> or less, The lighting method of the dielectric barrier discharge lamp. 8. The method of claim 7,
A method of lighting a dielectric barrier discharge lamp, wherein the average illuminance of the ultraviolet rays radiated to the outside of the discharge tube from a side surface located on the long side surface of the lower wall plate in the discharge tube is 10 mW / cm 2 or less. The method according to claim 1 or 4,
The light blocking member is a dielectric barrier discharge lamp having a configuration comprising a transparent member and a light shielding film. 11. The method of claim 10,
The said light shielding film is a dielectric barrier discharge lamp comprised from the baking material of the slurry (cloud liquid) which made the fine particle of the oxide which has an ultraviolet-shielding agent cloudy with a solvent. 12. The method of claim 11,
A dielectric barrier discharge lamp, wherein the primary particle diameter of the fine particles of the oxide is 10 to 100 nm. 12. The method of claim 11,
The fine particle of the oxide is yttrium oxide, dielectric barrier discharge lamp. 11. The method of claim 10,
The said light shielding film performs the light shielding by ultraviolet absorptivity, The dielectric barrier discharge lamp. 11. The method of claim 10,
The said light shielding film is a dielectric barrier discharge lamp whose film thickness is 10 micrometers or less. The method according to claim 1 or 4,
A dielectric barrier discharge lamp comprising the lower wall plate made of a synthetic quartz plate, and a wall plate or upper wall plate in the front and rear and left and right directions of four sides around the lower wall plate made of a molten quartz plate. The method according to claim 1 or 4,
It is a roughening film | membrane in which the front-back direction of the four side surface of the periphery of the said lower wall board, and the both side wall surfaces of the left-right direction were roughened, The said roughening film is the front-back direction and the left-right direction of the four side surface of the periphery of the said lower wall board. The dielectric barrier discharge lamp according to claim 1, wherein both side walls of the structure are made of synthetic quartz, and both side walls in the front-rear direction and the left-right direction on the periphery of the lower wall plate are roughened films roughened by hydrofluoric acid. The method according to claim 1 or 4,
A roughening film in which the front and rear and right and left side wall surfaces of the four side surfaces around the lower wall plate are roughened, wherein the roughening film is sanded on both side walls in the front and rear and left and right directions of the four side surfaces around the lower wall plate. A dielectric barrier discharge lamp, wherein a blast is injected. The dielectric barrier discharge lamp of Claim 1 or 4,
A power supply for outputting power for causing excimer light emission in the lamp;
Lead wire for supplying power from the power supply
Ultraviolet irradiation apparatus comprising a. 20. The method of claim 19,
The ultraviolet irradiation device in which the layer containing an organosilicon compound is formed in one part of the to-be-irradiated object of the said irradiation apparatus.

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