JP2005100934A - Excimer lamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an excimer lamp having a new structure in which the structure is simple, a discharge container has not been damaged by thermal expansion, and discharge can be generated stably. <P>SOLUTION: The excimer lamp comprises a discharge container that is made of a material for transmitting ultraviolet rays while gas for discharge is sealed inside; an internal electrode that is extended in the longitudinal direction inside the discharge container and is airtightly sealed at the end section of the discharge container; and an external electrode arranged on the outer surface of the discharge container. In the internal electrode, an outer surface at a part for discharging at an area with at least the outer electrode is covered with an inner pipe made of a dielectric material in which at least one end is open in the discharge space. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an excimer lamp that discharges through a dielectric material and emits excimer light, and particularly relates to an excimer lamp having an internal electrode in a discharge space.

As a technique related to the present invention, for example, there is Japanese Patent Application Laid-Open No. 2-7353, in which a discharge vessel is filled with a discharge gas for forming excimer molecules, and a dielectric barrier discharge (also known as an ozonizer discharge or silent operation). Describes an excimer lamp, that is, an excimer lamp that forms an excimer molecule and extracts the light emitted from the excimer molecule according to the revised edition “Discharge Handbook” published by the Institute of Electrical Engineers of Japan (see page 263, reprinted in June 2001, 7th edition). Is done. In addition, German Patent Publication DE4022279A1 discloses an excimer lamp that is lit in the unit of MHz. Further, "Silent discharge for the generation of ultraviolet and vacuum ultraviolet excimer radiation" (Pure & Appl. Chem., Vol. 62 No. 9, pp. 1667-1674, 1990) discloses an excimer lamp (also called a dielectric barrier discharge lamp) that is lit at 50 Hz to several MHz.
In these excimer lamps, the shape of the discharge vessel is entirely cylindrical, and at least a part of the discharge vessel also serves as a dielectric that performs discharge (dielectric barrier discharge) with a dielectric material interposed therebetween. Some are translucent to vacuum ultraviolet light (light with a wavelength of 200 nm or less) radiated from excimer molecules, and a net electrode is provided as one electrode on the outer surface of the discharge vessel. .

  Such excimer lamps have various characteristics not found in conventional low-pressure mercury discharge lamps or high-pressure discharge lamps, such as strong emission of ultraviolet light of a single wavelength, and light emission using such excimer lamps. The apparatus is disclosed in, for example, Japanese Patent No. 2854255, Japanese Patent Application Laid-Open No. 2002-168999, and the like.

  The excimer lamp (dielectric barrier discharge lamp) disclosed in Japanese Patent No. 2854255 and Japanese Patent Application Laid-Open No. 2002-168999 is a double-cylindrical type in which a cylindrical outer tube is also coaxially disposed outside a cylindrical inner tube. The inner electrode is arranged inside the inner tube, the outer electrode is arranged on the outer surface of the outer tube, and the space formed between the inner tube and the outer tube is used as the discharge space. .

FIG. 11 shows a schematic configuration of a double cylindrical excimer lamp. (A) shows the whole cross-sectional view, (b) shows the AA cross-sectional view of (a).
The excimer lamp 1 has a cylindrical shape as a whole and is made of synthetic quartz glass. In the discharge lamp 1, the outer tube 51 and the inner tube 52 are arranged coaxially to form a double cylindrical tube, and since both ends are closed, a discharge space is formed between the outer tube 51 and the inner tube 52. Excimer molecules are formed in the discharge space by dielectric barrier discharge, and a discharge gas, for example, xenon gas, that emits vacuum ultraviolet light from the excimer molecules is enclosed. As a numerical example, the discharge lamp 1 has a total length of 800 mm, an outer diameter of 27 mm, the inner tube 52 has an outer diameter of 16 mm, the outer tube 51 and the inner tube 52 have a thickness of 1 mm, and is lit at 400 W.
The inner electrode 2 that is one electrode is provided on the inner surface of the inner tube 52, and the net-like outer electrode 3 that is the other electrode is provided on the outer surface of the outer tube 51. The inner electrode 2 is in the shape of a pipe, and the mesh electrode 3 is seamlessly configured and has elasticity as a whole, so that the adhesion of the outer tube 51 can be improved.
An AC power supply (not shown) is connected between the inner electrode 2 and the outer electrode 3, thereby excimer molecules are formed in the discharge space and emit ultraviolet light. When xenon gas is used as the discharge gas, light having a wavelength of 172 nm is emitted.

By the way, this excimer lamp having a double cylindrical structure has the following problems.
First, since the two quartz glass tubes, the inner tube and the outer tube, are of a double cylindrical shape, the entire discharge vessel becomes large. Further, since the inner tube is supported by welding at the end, it is easily damaged by the influence of gravity.
Secondly, a manufacturing process for joining two quartz glass tubes at both ends is required, and this manufacturing process is complicated and complicated.
Thirdly, the inner tube is hotter than the coolable outer tube and is subjected to a large load due to thermal expansion. In particular, the stress is concentrated at the joint with the outer tube, and the lamp is elongated. The effect is so serious.

There is also an excimer lamp that has a structure in which an inner electrode is formed so as to extend in the discharge space instead of a double cylindrical type. For example, it is shown in Japanese translations of PCT publication No. 8-508363 and Unexamined-Japanese-Patent No. 2003-317670.
FIG. 12 shows the structure of the conventional example. In this structure, the discharge vessel 60 is formed of a single cylindrical body, an inner electrode 61 extends in the axial direction in the discharge space in the discharge vessel 60, and an outer electrode 62 is disposed on the outer surface of the discharge vessel 60. Is provided.

According to the above structure, since there is no equivalent to the inner tube in the double cylindrical type, some of the above problems of the double cylindrical type structure can be solved.
However, since the inner electrode is exposed in the discharge space, there is a problem in that the inner electrode is directly discharged, the inner electrode is easily deteriorated, and the discharge becomes unstable. Further, there is a problem that the deteriorated electrode component is discharged into the discharge space and spatter occurs in the discharge vessel, resulting in an early decrease in illuminance. In addition, since the discharge is directly performed on the inner electrode, the temperatures of the inner electrode and the discharge gas are likely to rise, and as a result, the light emission efficiency tends to be lowered.
In addition, since the dielectric material exists only in the vicinity of one of the electrodes, the balance of discharge is lost on the positive side and the negative side when AC lighting is performed.
Furthermore, unless attention is paid to the polarity of the power supplied to the electrode, an arc-like discharge is generated and excimer light is not generated efficiently. There is another problem such as burning out.
Japanese Patent Laid-Open No. 2-7353 Japanese Patent No. 2854255 JP 2002-168999 A, etc. Special table hei 8-508363 JP 2003-317670 A

  The problem to be solved by the present invention is to eliminate the complexity of the structure of the double cylindrical excimer lamp and to eliminate the trouble of the discharge of the excimer lamp having the structure in which the inner electrode is directly exposed in the discharge space. Another object of the present invention is to provide an excimer lamp having a novel structure in which an inner electrode in a discharge space is covered with a dielectric having an open end.

  An excimer lamp according to the present invention includes a discharge vessel that is made of a dielectric material that transmits ultraviolet rays, and in which a discharge gas is sealed. The excimer lamp extends in the longitudinal direction inside the discharge vessel and is airtight at the end of the discharge vessel. In the structure comprising a sealed inner electrode and an outer electrode disposed on the outer surface of the discharge vessel, the inner electrode has at least one outer surface of a portion that discharges between the outer electrode and at least one end of the discharge vessel. It is characterized in that it is covered by an inner tube made of a dielectric material that is open inside.

Further, both end portions of the inner tube are open in the discharge space.
Furthermore, the inner tube is supported by a discharge vessel by a support member.
In addition, the support means is attached to the inner tube, and a fixing means for restricting movement of the support member in the longitudinal direction is formed in the discharge vessel.
Furthermore, the inner tube is supported by an inner electrode.
Alternatively, one end of the inner tube is opened in the discharge space, and the other end is connected to the discharge vessel.
Alternatively, the inner electrode is sealed at both ends of the discharge vessel, and at least part of the inner electrode is formed with an elastic portion that can expand and contract in the longitudinal direction.

In the excimer lamp of the present invention, since the inner tube made of a dielectric material is provided on the outer periphery of the inner electrode, two dielectrics are interposed between the inner electrode and the outer electrode. The discharge is stably and uniformly formed in the space. In addition, since arc-like discharge is not generated regardless of the power supply polarity, the excimer light generation efficiency is high and the problem that the electrode burns out does not occur.
In addition, since the inner tube has its end opened in the discharge space, it can be freely expanded and contracted without restraining thermal expansion in the longitudinal direction, so it is based on a structure in which the discharge vessel is joined at both ends. The problem of damage and breakage due to stress concentration and thermal strain is solved.
In addition, since the discharge gas in the inner tube can flow into the discharge space through the open end, the temperature rise of the inner electrode covered with the inner tube can be suppressed, the wear can be prevented, and the temperature in the discharge vessel can be averaged. Thus, the temperature rise of the discharge gas is suppressed, and the decrease in light output can be prevented.

FIG. 1 shows a first embodiment of an excimer lamp of the present invention.
The excimer lamp 1 is composed of a tubular discharge vessel 10 as a whole, and a light emitting portion 11 filled with a discharge gas and a sealing portion 12 that hermetically seals the light emitting portion 11 are formed at both ends thereof. The material of the discharge vessel 10 is made of a material that functions as a dielectric by dielectric barrier discharge and that transmits vacuum ultraviolet light well, such as synthetic quartz glass.
Inside the discharge vessel 10, the rod-shaped inner electrode 2 is arranged so as to extend substantially at the center of the discharge vessel 10, and the outer electrode 3 is arranged in close contact with the outer surface of the discharge vessel 10. Both ends of the inner electrode 2 are respectively joined to the metal foil 13 in the sealing portion 12, and the external leads 14 are further joined to the metal foil 13.
In the discharge space formed inside the light emitting unit 11, excimer molecules are formed by a discharge (dielectric barrier discharge) involving a dielectric material, and a discharge gas that emits vacuum ultraviolet light from the excimer molecules, for example, Xenon gas is enclosed.

The inner electrode 2 is a rod-like electrode such as tungsten, and a coil-like elastic portion 21 is formed at the end. An inner tube 22 made of a dielectric material is provided around the inner electrode 2 so as to cover the inner electrode 2, and the inner electrode 2 is inserted into the inner tube 22. The inner tube 22 is made of, for example, synthetic quartz glass and is covered with an outer surface of a portion that discharges at least between the inner electrode 2 and the outer electrode 3, and an end portion of the inner tube 22 is an end of the outer electrode 3. It extends beyond the department.
The inner electrode 2 and the inner tube 22 may be loosely adhered via a minute gap, or a larger gap may be formed. Further, the coiled elastic portion 21 is not necessarily provided at two locations of the inner electrode 2 but may be provided at least at a part.

In this embodiment, the inner tube 22 is open at both ends in the discharge space and does not exist at both ends of the inner electrode 2. Therefore, the inner electrode 2 is directly exposed to the discharge gas without being covered by the inner tube 22 at both ends.
The inner tube 22 is fixed inside the discharge vessel 10 by a ring-shaped support member 30. The support member 30 is fitted to the inner tube 22 and fixed to the inner tube 22 by welding or adhesion.

  The outer electrode 3 is an electrode in which a metal wire is formed in a net shape, and is arranged so as to cover the outer surface of the discharge vessel 10. For this reason, the emitted light from the discharge vessel 10 is emitted through the mesh of the outer electrode 3. Note that the outer electrode 3 having a structure in which one metal wire is knitted seamlessly is advantageous in that the adhesion to the discharge vessel is increased.

  When power is supplied to the inner electrode 2 and the outer electrode 3 by a power supply device (not shown), a discharge is generated between the electrodes via the discharge vessel 10 and the inner tube 22 that are dielectric materials, and excimer emission is generated in the discharge gas. Arise.

Although the inner tube 22 is supported by the discharge vessel 10 by the support member 30, the support member 30 is not necessarily required when the inner electrode 2 has sufficient self-holding rigidity. It may be supported by the electrode 2.
In this case, in order to prevent the inner tube 22 from moving in the longitudinal direction, the coiled elastic portion 21 formed on the inner electrode 2 can also function as a movement restricting member for the inner tube 22 in the longitudinal direction. In this case, the elastic portion 21 is disposed adjacent to the end of the inner tube 22 and at least has a larger diameter than the inner diameter.

In the structure of the excimer lamp of this embodiment, since the dielectric is also covered on the inner electrode in the discharge space, the discharge between the outer electrode and the outer electrode becomes stable, and a uniform state can be maintained. The generation of undesired arc discharge is prevented, excimer light generation efficiency is high, and the problem that the electrode burns out does not occur.
Furthermore, since the inner tube has a structure in which the end portion is opened in the discharge space, the thermal expansion in the longitudinal direction is freely restricted without any restriction. The problem of damage and breakage based on the conventional structure is solved. Further, the discharge gas in the inner tube flows into the discharge space through the open end to suppress the temperature rise of the inner electrode, and the wear can be prevented, and the temperature of the discharge gas is averaged and the temperature is reduced. The rise is suppressed, and a decrease in light output can be prevented.

  In addition, since the inner electrode has an elastic part, even if the inner electrode thermally expands, the thermal expansion is absorbed by the elastic part. Therefore, the discharge vessel made of quartz glass having a different thermal expansion coefficient is used. The sealing portion is not affected and the discharge vessel can be prevented from being damaged.

FIG. 2 shows a second embodiment of an excimer lamp according to the present invention.
The difference from the excimer lamp shown in FIG. 1 is that the inner electrode 2 is not a rod-like electrode but a coil-like electrode as a whole, and the outer electrode 3 is not a mesh electrode but a semi-cylindrical shape (a bowl shape). It is comprised from the metal plate of this.
The advantage of the inner electrode being in the shape of a coil is that it is made of a thin metal wire, so that the weight can be reduced compared to a rod-shaped electrode. Reducing the weight is advantageous in terms of vibration resistance and impact resistance. Further, since the electrode itself is an elastic body, there is an advantage that it is not necessary to provide an elastic portion separately as in the case of the rod-shaped electrode, and it can be manufactured at low cost.
The advantage that the outer electrode is a semi-cylindrical metal plate is that the assembly workability is better than that of the mesh electrode. That is, in the case of a mesh electrode, it is necessary to pass it around the discharge vessel or to wrap it, but in the case of a semi-cylindrical electrode, it is only necessary to insert a part that has been molded in advance according to the outer diameter of the discharge vessel. The assembly work is completed. In addition, when the metal plate is reflective to ultraviolet rays, the light output in one direction can be improved.

FIG. 3 shows an enlarged structure of the end portion of the discharge vessel of the excimer lamp shown in FIG.
It is explanatory drawing for prescribing | regulating the area | region where the inner side electrode 2 is covered with the inner side tube 22, in other words, the area | region where the inner side electrode 2 is exposed to discharge space.
In the figure, the distance D between the end of the outer electrode 3 and the end of the inner tube 22 must be at least larger than twice the discharge distance d (the figure is not in the numerical relationship for convenience of explanation).
That is, when the relationship of D> 2d is not satisfied, there is a possibility that a strong discharge is generated in the exposed portion of the inner electrode 2 and the outer electrode 3, and this discharge tends to be an unstable discharge as described above. It is. In particular, in the case of alternating current lighting, since the polarity relationship changes at the position of the dielectric each time the polarity is changed, the discharge tends to be unbalanced.
It is preferable to satisfy the relationship of D> 4d, and more preferably to satisfy the relationship of D> 6d.

FIG. 4 shows the support member 30 of the inner electrode 2. (A) shows a bobbin-shaped support member, (b) shows a hollow support member using two discs, and (c) shows a plate-like support member.
The inner tube 22 is supported with respect to the discharge vessel 10 by a support member 30 attached to the inner tube 22 by welding or adhesion. The support member 30 prevents the inner electrode 22 as well as the inner electrode 2 from drooping due to gravity, and prevents damage to the inner tube 22 due to the drooping and positional unevenness of discharge. Because. In particular, when the discharge vessel 10 is long, the problem becomes remarkable. For example, when the length of the discharge vessel (the length of the discharge space) is 500 to 600 mm or more, the need for the support member increases.

The support member shown in (a) is a bobbin-shaped support member 30, which is fitted to the inner tube 22, and is attached to the inner tube 22 by welding or adhesion. And it has the structure where the hollow 100 formed in the discharge vessel 10 engages with the recess on the circumference, thereby restricting the inner tube 22 from moving on the inner electrode 2 in the longitudinal direction. Yes.
In the case of the two plate-like support members 30 shown in (b), the recess 100 is engaged between them.
Furthermore, in the case of the plate-like support member 30 shown in (c), two depressions 100 are formed on both sides of the support member 30 to restrict the movement of the inner tube 22 in the longitudinal direction.

These depressions 100 function as fixing means for loosely fixing the support member 30 to the discharge vessel 10 in order to restrict the inner tube 22 from moving in the longitudinal direction with respect to the discharge vessel 10. Therefore, it is not always necessary to form it on the entire outer periphery of the discharge vessel 10, and it may be formed at one place or several places on the circumference.
And these hollows 100 can be made by dimple processing, for example.
4 shows the structure of one end of the discharge vessel 10, a plurality of support members 30 may be provided at the central portion or the other end of the discharge vessel.
In this case, the depressions 100 do not need to be provided in all the support members 30, and the movement of the inner tube 22 in the longitudinal direction can be restricted by providing the depressions 100 in at least one support member.

  FIG. 5 shows a third embodiment of the present invention. In this embodiment, in the first embodiment shown in FIG. 1, the inner tube 22 is rod-shaped with respect to the structure in which the inner tube 22 penetrating the rod-shaped inner electrode 2 is supported by the support member 30 with respect to the discharge vessel 10. The inner electrode 2 is supported by a support 2a.

  FIG. 6 further shows a fourth embodiment. In the second embodiment shown in FIG. 2, the coiled inner electrode 2 is coiled with respect to the structure inserted so as to contact the inner tube 22. A supporter 2 b is provided on the electrode 2, and the coiled electrode 2 is supported in the inner tube 22.

FIG. 7 shows a fifth embodiment. In the first to fourth embodiments, the structure in which the inner electrode 2 is sealed at both ends of the discharge vessel 10 is shown. However, the present invention is not limited thereto, and a structure in which the inner electrode 2 is sealed only at one end may be used.
In FIG. 7, the inner electrode 2 is sealed with a pinch seal or the like only at one end portion of the discharge vessel 10, and in the figure only at the right end portion 10a, and protrudes to the outside, and the left end portion 10b of the discharge vessel 10 is closed. doing.
According to this embodiment, since the inner electrode 2 is sealed to the discharge vessel 10 only at one end, the influence on the discharge vessel 10 due to thermal expansion can be further reduced.

In the first to fifth embodiments, the inner tube 22 is shown in which both ends are open in the discharge space, but it is not always necessary that both ends are open, and one end is discharged. Such a sixth embodiment is shown in FIG. 8 and may be connected to a container.
In FIG. 8, the inner tube 22 has a left end 22a opened in the discharge space, and a right end 22b connected to the discharge vessel 10 by welding or the like.

Also in the sixth embodiment, the inner tube 22 is free because the left end 22a is open. Therefore, the inner tube 22 is not restrained by other members even with respect to the thermal expansion of the inner tube 22. There is no stress concentration due to distortion at the mounting location.
In the sixth embodiment, as described in the first embodiment, the structure in which the support member 30 is attached to the inner tube 22 to support the inner tube 22 with respect to the discharge vessel 10 is shown. In the embodiment, since the inner tube 22 is connected to the discharge vessel 10 at the one end portion 22b, the support member 30 that supports the inner tube 22 may be unnecessary particularly in the case of a small lamp.

In addition, about the support member 30 in each said Embodiment 1-6, as shown in FIG. 9, you may form the notch 31 in the light extraction direction (downward in a figure). The support member 30 is fixed to the inner tube 22 or the discharge vessel 10 by welding or the like.
By doing so, the problem that the discharge is not formed in the support member 30 part or that the light from other light emitting portions is blocked and is not emitted outside is solved. That is, in the structure in which the support member 30 is provided, since the support member 30 exists, there is no discharge space between the inner and outer electrodes 2 and 3 in this portion, and no discharge is formed in this portion, or from other light emitting portions. Is not shielded from being emitted to the outside of the discharge vessel 10 by the support member 30, but by forming a discharge space below the support member 30 by the notch 31, these problems are avoided. Can be eliminated.

  The excimer lamp of the present invention is not limited to the structure shown in FIGS. For example, the external electrode is not limited to a mesh electrode or a semi-cylindrical body, and may be formed on the outer surface of the discharge vessel by printing or the like. Further, the outer electrode does not need to be physically constituted by one member, and can be electrically connected by being divided into a plurality of parts in the longitudinal direction of the discharge vessel. The advantage of this structure is that a long product can be easily manufactured and the light distribution can be adjusted.

The inner electrode is not limited to a rod-shaped electrode or a coil-shaped electrode, and may be anything as long as it has electrical characteristics in the inner tube and can be an electrode for excimer light emission. For example, depositing a metal thin film on the inner surface of the inner tube. The advantage of this metal thin film is that the inner tube can be made smaller and the metal thin film can be used as a reflection mirror.
The inner electrode can also be tubular. In this case, the adhesiveness with the inner tube can also be improved by forming a C-shaped cross section having a cutout in a part of the cross section.

  When the inner electrode is composed of a coil, the coil is not formed from a single metal wire, but a structure in which a plurality of coils are joined together, a structure in which rod-shaped portions and coil portions are alternately arranged, and a coil It is possible to apply a structure in which the pitch is changed in the longitudinal direction. In particular, when there are variations in the inner diameter and thickness of the discharge vessel, it may be effective for eliminating the non-uniformity of excimer emission due to the variation.

  The structure of the sealing portion of the discharge vessel is not limited to the pinch seal, but may be another foil seal, that is, a shrink seal structure, or a so-called step seal. The advantage of the step seal is that the bondability between the glass and the electrode is improved, and the occurrence of gas leakage and cracks in the sealed portion can be prevented more reliably.

In addition, the support member that supports the inner tube has been described as being attached to the inner tube by welding or the like, but is not limited to this, and the inner tube is loosely fitted to the support member. May be supported. Even in this case, the inner tube can freely expand and contract without being restrained by the support member in the thermal expansion in the longitudinal direction. However, since it is not preferable that the inner tube moves unnecessarily large in the longitudinal direction, a fixing means for restricting the movement of the inner tube in the longitudinal direction is separately provided on the inner electrode side or the like as necessary. .
As described above, the support member for the inner tube may be structured to be attached to either the discharge vessel or the inner tube.

  A getter may be disposed in the discharge space. The getter is made of, for example, barium or zirconium, and is effective because it can adsorb an impure gas. As for the arrangement of the getters, a dedicated getter accommodating chamber can be fixed by, for example, a structure provided at the end of the discharge vessel or magnetic holding means.

In the structure shown in FIG. 1, as a numerical example, the length of the discharge vessel 10 (including the sealing portion) is 400 mm to 1500 mm, for example, 1000 mm, and the outer diameter of the discharge vessel 10 is φ10 mm to 20 mm. For example, it is 15 mm. The length of the inner tube 22 is 200 mm to 1300 mm, for example, 800 mm, the outer diameter of the inner tube 22 is φ4 mm to 8 mm, for example, 5 mm, and the inner diameter is φ2 mm to 6 mm, for example, 3 mm. . The length of the inner electrode (rod-like electrode) is 300 mm to 1400 mm, for example, 900 mm, and the outer diameter is φ1.5 mm to 5.9 mm, for example, 2.8 mm. The length of the elastic portion 21 is 10 mm to 30 mm, for example, 20 mm, and the outer diameter is φ2 mm to 7 mm, for example, 4 mm.
The width of the support member 30 is 3 mm to 7 mm, for example, 5 mm.

  In the structure shown in FIG. 2 and different from the structure shown in FIG. 1, the outer diameter of the coiled inner electrode is 1.5 mm to 5.9 mm, for example, 2.8 mm. It is.

  When the numerical example is shown about the part which is the structure shown in FIG. 3 and is different from the structure shown in FIG. 1 and FIG. 2, the discharge distance d is 2 mm to 7 mm, for example, 5.0 mm, and the distance D is It is a numerical range larger than 2d, and is 4 mm to 14 mm, for example, 10 mm.

The excimer lamp has a discharge space with dielectrics interposed between the outer electrode and the inner electrode. The excimer lamp, which is also called a dielectric barrier discharge lamp, has an excellent feature that is not found in conventional low-pressure mercury lamps and high-pressure discharge lamps, and strongly emits single-wavelength vacuum ultraviolet light.
The light of a single wavelength is determined by the sealed gas in the discharge vessel. In the case of xenon gas (Xe), light of wavelength 172 nm, in the case of argon gas (Ar) and chlorine gas (CL), light of wavelength 175 nm, krypton ( In the case of Kr) and iodine (I), light having a wavelength of 191 nm, in the case of argon (Ar) and fluorine (F), light having a wavelength of 193 nm, in the case of krypton (Kr) and bromine (Br), the light having a wavelength of 207 nm, krypton In the case of (Kr) and chlorine (CL), light having a wavelength of 222 nm is emitted. Further, it has a feature that it can be blinked and lighted instantaneously (within 1 second) as necessary.

  The voltage waveform supplied from the power supply device to the excimer lamp for excimer light emission is not limited to a sine wave, and may be a pulse waveform. In this case, instead of continuously supplying pulses, a pulse waveform providing an interval (rest period) is preferable in terms of light emission efficiency, and the pulse waveform is preferably applied in a steep rising waveform. This is because applying a voltage having a steep rising waveform approaches a state in which a voltage is directly applied to the gas itself in the discharge vessel as compared to applying a gentle voltage such as a sine wave voltage. The rest period is provided so that excimer molecules once generated are not destroyed. As an example of the numerical value of rising, it is selected from the range of 0.03 μs to 1 μs, for example 0.5 μs, and the pulse width is selected from the range of 0.5 μs to 5 μs, for example, 1 μs. The rest period is selected from the range of 1 μs to 100 μs, for example, 29 μs.

FIG. 10 shows a schematic configuration of an irradiation apparatus using an excimer lamp according to the present invention.
The excimer irradiation apparatus 40 is entirely formed in a box shape from the metal block 41.
The metal block 41 is provided with a groove, and the excimer lamp 10 (10a, 10b, 10c) is arranged so as to fit into the groove. The metal block 41 is provided with cooling water through holes 42 (42 a, 42 b) through which cooling water flows and sensors 43 (43 a, 43 b, 43 c) that detect the emitted light of the excimer lamp 1. The metal block 41 is made of, for example, aluminum because of its high heat transfer characteristics, easy processing, and high reflection characteristics of vacuum ultraviolet light. Although not shown, the metal block 41 is provided with a temperature detection sensor for the discharge vessel.

The irradiation device 40 is provided with an inlet 44a and an outlet 44b for flowing an inert gas. The introduction port 44a is connected to a gas cylinder or the like via a valve, and the discharge port 44b is also connected to a vacuum pump via the valve. Nitrogen gas is generally used as the inert gas, but argon gas or the like can also be used. Further, the inert gas can be continuously flown so as to be introduced from the introduction port 44a and discharged from the discharge port 44b during the treatment step or before and after the treatment.
A power feeding device 45 is disposed outside the irradiation device 40.

A processing object W receiving ultraviolet rays emitted from the excimer lamp 10 is placed on the processing table 46 outside the irradiation device 40. The processing base 46 is made of, for example, stainless steel, and can heat the processing object W by disposing a filament heater made of nichrome wire inside. In addition, by providing a lifting mechanism on the processing table 46, which is not shown, the workpiece W can be brought close to the excimer lamp 1, and it can be transported in the horizontal direction by providing a transport mechanism. It becomes possible.
The processing object W is supplied with processing gas such as oxygen gas, silane-based gas, hydrogen gas, and argon gas, and the processing gas and the emitted light from the excimer lamp 1 react to perform processing.

In addition, the above-described irradiation device is not provided with a transmission member that separates both the lamp and the processed product. For this reason, the whole apparatus is reduced in size, and the advantage is great in that it is not necessary to use an expensive ultraviolet light transmitting window member. This is because the excimer lamp of the present invention is small in size, so that the distance between the excimer irradiation device 40 and the workpiece W can be reduced, so that the metal block 41 is generated by the inert gas flow flowing from the inlet port 44a to the outlet port 44b. Can prevent oxidation.
However, it does not exclude the provision of a transmissive member that separates the lamp and the processed product. By providing the transmissive member, there is an advantage that the problem that the suspended matter from the processed material adheres to the lamp or the vicinity thereof can be solved.

Embodiment 1 of the excimer lamp of the present invention will be described. Embodiment 2 of an excimer lamp according to the present invention will be described. The principal part enlarged view of FIG. 1 is shown. The principal part enlarged view of FIG. 2 is shown. Embodiment 3 of the excimer lamp of this invention is shown. Embodiment 4 of the excimer lamp of this invention is shown. Embodiment 5 of the excimer lamp of the present invention will be described. Embodiment 6 of an excimer lamp of the present invention will be described. Embodiment 7 of an excimer lamp of the present invention will be described. The irradiation apparatus using the excimer lamp of this invention is shown. A conventional excimer lamp is shown. Another conventional example is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Excimer lamp 2 Inner electrode 3 Outer electrode 10 Discharge vessel 11 Light emission part 12 Sealing part 21 Elastic part 22 Inner pipe | tube 30 Support member 100 Indentation (fixing means)

Claims (7)

A discharge vessel made of a material that transmits ultraviolet light and having a discharge gas sealed therein; an inner electrode that extends in the longitudinal direction inside the discharge vessel and is hermetically sealed at the end of the discharge vessel; and a discharge In an excimer lamp consisting of an outer electrode disposed on the outer surface of the container,
The excimer lamp is characterized in that at least one outer surface of the inner electrode is covered with an inner tube made of a dielectric material having at least one end opened in the discharge space. . The excimer lamp according to claim 1, wherein both end portions of the inner tube are open in the discharge space.   The excimer lamp according to claim 2, wherein the inner tube is supported by a discharge vessel by a support member.   The excimer lamp according to claim 3, wherein the support member is attached to an inner tube, and a fixing means for restricting movement of the support member in a longitudinal direction is formed in the discharge vessel. .   The excimer lamp according to claim 2, wherein the inner tube is supported by an inner electrode.   The excimer lamp according to claim 1, wherein one end of the inner tube is opened in the discharge space, and the other end is connected to the discharge vessel. 2. The excimer lamp according to claim 1, wherein the inner electrode is sealed at both ends of the discharge vessel, and at least a part thereof is formed with an elastic portion that can expand and contract in a longitudinal direction.

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