Excimer lamp

Abstract

To provide an excimer lamp having an enlarged light emitting region.SOLUTION: The excimer lamp includes an arc tube including an outer tube having an exhaust tube remaining portion near an end portion of an outer peripheral surface and an inner tube inserted into the outer tube, the outer tube and the inner tube being joined at both end portions to form a sealed space, an inner electrode disposed inside the inner tube, and an outer electrode in contact with the outer peripheral surface of the outer tube, the outer electrode being also formed on the exhaust tube remaining portion, A conductive member is provided in the sealed space, the conductive member has a base portion located close to the inner electrode and a front end portion located close to the outer electrode and the exhaust pipe remaining portion and extends from the base portion to the front end portion, and the front end portion of the conductive member is located closer to a center side of the outer pipe in a longitudinal direction than the exhaust pipe remaining portion.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an excimer lamp. [Background technology]

[0002] 2. Description of the Related Art Conventionally, excimer lamps have been used as light sources that emit ultraviolet light for use in FPD and semiconductor process equipment, optical cleaning equipment, and the like.

[0003] In recent years, in the field of optical cleaning devices for FPDs, there has been a demand for extending the effective light emission length as display substrates become larger. Patent Document 1 describes an excimer lamp device in which multiple excimer lamps are arranged in the tube axis direction of the excimer lamps in order to extend the effective light emission length. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-192823 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide an excimer lamp with an expanded light-emitting area. [Means for solving the problem]

[0006] The inventors of the present invention have investigated using the end regions of the excimer lamp as the light-emitting region in order to extend the effective light-emitting length.

[0007] Some excimer lamps have an exhaust pipe remnant in the end region of the outer peripheral surface of the arc tube of the excimer lamp. The exhaust pipe remnant has irregularities relative to the surrounding outer tube, a thickness that is different from or varies in thickness from the surrounding outer tube, and as a result, distortions are inherent. For this reason, in the past, an outer electrode was not provided on the exhaust pipe remnant, and it was not used as a light-emitting region. However, in order to expand the light-emitting region, we investigated providing an outer electrode in the end region including the exhaust pipe remnant.

[0008] Figure 4 shows an enlarged cross-sectional view of the main parts of an excimer lamp in which an outer electrode is also arranged in an end region including the remaining part of the exhaust pipe. The excimer lamp 500 shown in Figure 4 has an arc tube 10 in which a light-emitting gas is sealed. The arc tube 10 has an inner tube 2 inserted into an outer tube 1, and the ends of the outer tube 1 and inner tube 2 are joined to form a sealed end 3. An inner electrode 6 is formed on the inner circumferential surface 2i of the inner tube 2. A mesh-shaped outer electrode 7 is formed on the outer circumferential surface 1s of the outer tube 1. A mesh-shaped outer electrode 7 is also formed in the end region of the outer tube 1 including the remaining part 5 of the exhaust pipe. As a result, excimer light is emitted even in the end region including the remaining part 5 of the exhaust pipe.

[0009] However, as a result of intensive research by the inventors, it was found that providing an outer electrode 7 near the end of the arc tube 10, including the remaining exhaust pipe portion 5, causes the following problem. If a mesh-shaped outer electrode 7 is provided in the remaining exhaust pipe portion 5, linear discharges dc are likely to concentrate due to the unique shape of the remaining exhaust pipe portion 5. Linear discharges dc are discharges with higher discharge energy than the surrounding area. If linear discharges dc occur in the remaining exhaust pipe portion 5, which is already distorted, the high discharge energy causes further distortion to accumulate in the remaining exhaust pipe portion 5, eventually causing cracks in the remaining exhaust pipe portion 5, causing light-emitting gas to leak and shortening the life of the excimer lamp 500. In other words, the life of the excimer lamp 500 is shortened.

[0010] When arranging the outer electrode 7 in the end region of the outer pipe 1, it is also possible to consider a method in which the outer electrode 7 is not arranged only around the remaining exhaust pipe portion 5. However, no matter what method is used to manufacture the outer electrode 7, not arranging the outer electrode 7 only around the remaining exhaust pipe portion 5 will complicate the manufacturing method, increasing the technical difficulty and the manufacturing cost.

[0011] Another possible method is to arrange the outer electrode 7 in the end region including the remaining exhaust pipe portion 5, and then remove the outer electrode 7 only from the periphery of the remaining exhaust pipe portion 5. However, this adds a removal step of removing the outer electrode 7 only from the periphery of the remaining exhaust pipe portion 5, which increases manufacturing costs, and also creates new technical problems, such as the mesh coming loose from the ends of the conductive wires that remain after the removal, by removing some of the conductive wires that make up the mesh electrode.

[0012] Therefore, the inventor has created the following excimer lamp. The excimer lamp of the present invention is an arc tube having an outer tube having an exhaust pipe remnant near an end of an outer peripheral surface, and an inner tube inserted into the outer tube, the outer tube and the inner tube being joined together to form a sealed space; an inner electrode disposed inside the inner tube; an outer electrode in contact with the outer peripheral surface of the outer tube, the outer electrode is also formed on the remaining portion of the exhaust pipe; a conductive member provided in the sealed space, the conductive member having a base portion located close to the inner electrode and a tip portion located close to the outer electrode and the remaining portion of the exhaust pipe, the conductive member extending from the base portion to the tip portion; The tip end of the conductive member is located closer to the center of the outer pipe in the longitudinal direction than the remaining portion of the exhaust pipe.

[0013] In the excimer lamp, an outer electrode is also present in the remainder of the exhaust pipe. However, the conductive member disposed in the sealed space has a structure and arrangement that makes it difficult for linear discharge to occur in the remainder of the exhaust pipe. The structure and arrangement of the conductive member are specifically described below. In the excimer lamp, the conductive member has a structure having a base and a tip, and is disposed so that the base is close to the inner electrode and the tip of the conductive member is close to the outer electrode. Therefore, when a voltage for generating a dielectric barrier discharge is applied between the inner electrode and the outer electrode, linear discharge occurs between the inner electrode and the base of the conductive member, and linear discharge occurs between the outer electrode and the tip of the conductive member. The tip close to the remainder of the exhaust pipe redirects linear discharges that would otherwise be directed toward the remainder of the exhaust pipe toward the outer electrode formed outside the remainder of the exhaust pipe. In other words, the presence of the tip close to both the outer electrode and the remainder of the exhaust pipe allows the conductive member to deflect linear discharges that would otherwise be directed toward the remainder of the exhaust pipe.

[0014] While distortion accumulates in the remaining part of the exhaust pipe, distortion does not accumulate in the outer pipe other than the remaining part of the exhaust pipe, which is the destination of the linear discharge. Because the shapes of the outer pipe and the outer electrode are uniform, linear discharge is less likely to concentrate on the outer pipe other than the remaining part of the exhaust pipe. Therefore, even if the discharge energy of the linear discharge is applied to the outer pipe other than the remaining part of the exhaust pipe, cracks are less likely to occur in the outer pipe.

[0015] As a result, by disposing the outer electrode at the end of the outer peripheral surface where the remaining portion of the exhaust pipe is located, the light emitting portion is enlarged.

[0016] In the excimer lamp, the tip of the conductive member does not have to be in contact with the outer tube, which prevents the conductive member or the outer tube from being damaged when the conductive member is inserted into the outer tube.

[0017] In the excimer lamp, a fixing member for fixing the conductive member may be provided within the sealed space.

[0018] In the excimer lamp, the fixing member may be annular and extend radially from the inner tube, and may be located between the remaining portion of the exhaust pipe and the tip end.

[0019] the inner tube is composed of a first portion located on a longitudinal center side and having a small thickness, and a second portion located on an end side in the longitudinal direction and having a large thickness, The fixing member may be located in the second portion. [Effects of the Invention]

[0020] This makes it possible to provide an excimer lamp with an expanded light-emitting area. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a cross-sectional view of an embodiment of an excimer lamp. [Figure 2] FIG. 2 is an enlarged cross-sectional view of a main part of the excimer lamp of FIG. [Figure 3A] 1A to 1C are diagrams illustrating the manufacturing process of an excimer lamp. [Figure 3B] 1A to 1C are diagrams illustrating the manufacturing process of an excimer lamp. [Figure 3C] 1A to 1C are diagrams illustrating the manufacturing process of an excimer lamp. [Figure 3D] 1A to 1C are diagrams illustrating the manufacturing process of an excimer lamp. [Figure 4] FIG. 10 is an enlarged cross-sectional view of a main part showing a comparative example of an excimer lamp. DETAILED DESCRIPTION OF THE INVENTION

[0022] The excimer lamp will be described below with reference to the drawings as appropriate. Note that the drawings are all schematic illustrations, and the dimensional ratios and numbers in the drawings do not necessarily match the actual dimensional ratios and numbers.

[0023] First, one embodiment of an excimer lamp will be described with reference to Figures 1 and 2. Figure 1 is an overall view of an excimer lamp 100. Figure 2 is an enlarged view of a main portion of the excimer lamp 100 of Figure 1. In the following description, the direction in which the arc tube 10 of the excimer lamp 100 extends (tube axis direction) is referred to as the X direction. When expressing a direction, if a distinction is made between positive and negative, it is written with a positive or negative sign, such as "+X direction" and "-X direction." When expressing a direction without distinguishing between positive and negative, it is simply written as "X direction."

[0024] The excimer lamp 100 has an arc tube 10 and two electrodes (6, 7) arranged on the outside and inside of the arc tube 10, respectively. The arc tube 10 has a double-tube configuration consisting of an outer tube 1 and an inner tube 2 inserted into the outer tube 1. The tube axes of the outer tube 1 and the inner tube 2 are both located on line L1. The ends of the outer tube 1 and the inner tube 2 are joined to form a sealed end 3. The arc tube 10 has the outer tube 1, the inner tube 2, and the sealed end 3, and the interior of the arc tube 10 is sealed. In other words, the space between the outer tube 1 and the inner tube 2 is a sealed space 9 (see Figure 2).

[0025] Various dimensions of the arc tube 10 are shown with reference to Figure 2. The radius r1 of the outer tube 1 is preferably 15 mm or more and 35 mm or less, and preferably 15 mm or more and 30 mm or less. The radius r2 of the inner tube 2 is preferably 5 mm or more and less than 15 mm, and preferably 7 mm or more and 13 mm or less. The distance g1 between the inner circumferential surface 1i of the outer tube 1 and the outer circumferential surface 2s of the inner tube (when the inner tube 2 has a varying thickness, the outer circumferential surface at the thinnest part) is preferably 8 mm or more and 20 mm or less, and preferably 10 mm or more and 15 mm or less.

[0026] The two electrodes (6, 7) are the inner electrode 6 in contact with the inner circumferential surface 2i of the inner tube 2 and the outer electrode 7 in contact with the outer circumferential surface 1s of the outer tube 1. The outer electrode 7 is an electrode formed in contact with the outer circumferential surface 1s. In this embodiment, the outer electrode 7 is a mesh electrode with numerous light-transmitting openings. The mesh electrode of this embodiment is a net-patterned electrode in contact with the outer circumferential surface 1s, with multiple conductive wires extending along the X direction and multiple conductive wires extending along the circumferential direction of the outer circumferential surface 1s intersecting with each other. Since FIGS. 1 and 2 show only one cross section of the excimer lamp 100 along the XY plane, the cross sections of the mesh-shaped conductive wires of the outer electrode 7 are shown separately. However, in reality, the conductive wires shown separately are connected to each other. In FIG. 2, the cross sections of the conductive wires constituting the outer electrode 7 are shown as rectangular, but the cross-sectional shape of the conductive wires is not particularly limited and may be approximately circular. The wire diameter is not particularly limited, but is preferably 0.1 mm to 2 mm. The mesh electrode preferably has a mesh opening of 1 mm to 10 mm, and more preferably 2 mm to 8 mm. The outer electrode 7 may have a shape other than a mesh electrode, such as a coil electrode spirally wound around the outer peripheral surface 1s. Both the mesh electrode and the coil electrode have a light-transmitting portion in the area where the outer electrode 7 is disposed, allowing light emitted from the arc tube to pass through the area where the outer electrode 7 is disposed and be extracted. The outer electrode 7 may be formed up to the boundary between the outer tube 1 and the sealed end 3. Furthermore, as shown in FIG. 2, the outer electrode 7 may be formed so as to extend beyond the boundary between the outer tube 1 and the sealed end 3 and cover a portion of the sealed end 3. The outer electrode 7 may cover most of the sealed end 3, but if the outer electrode 7 is too close to the inner electrode 6, it becomes difficult to generate a dielectric barrier discharge. Therefore, the outer electrode 7 and the inner electrode 6 are preferably positioned so that the distance between them is 25 mm or more.

[0027] The inner electrode 6 is a sheet-like electrode formed without gaps along the inner circumferential surface 2i. The thickness of the inner electrode 6 is preferably 0.1 mm or more and 1.5 mm or less. The inner electrode 6 may be a mesh electrode like the outer electrode 7, or may be a coil electrode wound spirally in contact with the inner circumferential surface 2i. The outer electrode 7 and the inner electrode 6 are each connected to a power supply member (not shown). The sealed space 9 is filled with a luminescent gas, and applying a voltage between the two electrodes (6, 7) via the power supply member generates a dielectric barrier discharge, causing the luminescent gas in the arc tube 10 to emit excimer light. In this embodiment, xenon gas is used as the luminescent gas, and light with a wavelength of 172 nm is emitted by excimer light emission. Of course, other luminescent gases may be used to emit light with wavelengths other than 172 nm.

[0028] The remaining exhaust pipe portion 5 is a trace left on the outer tube 1 after the exhaust pipe has been removed. Details of the exhaust pipe will be described later. The remaining exhaust pipe portion 5 has irregularities relative to the surrounding outer tube 1. More specifically, the outer peripheral surface of the remaining exhaust pipe portion 5 protrudes slightly from the outer peripheral surface 1s around the remaining exhaust pipe portion 5, and the inner peripheral surface of the remaining exhaust pipe portion 5 is slightly recessed from the inner peripheral surface 1i around the remaining exhaust pipe portion 5. The thickness of the remaining exhaust pipe portion 5 differs from the thickness of the outer tube 1 around the remaining exhaust pipe portion 5, and the thickness varies locally. Furthermore, a mesh-shaped outer electrode 7 is also formed on the remaining exhaust pipe portion 5. Since the remaining exhaust pipe portion 5 is located in the end region of the arc tube 10, the outer electrode 7 is also arranged in the end region of the arc tube 10.

[0029] The remaining exhaust pipe portion 5 has a shape that is the cross-sectional shape of the exhaust pipe projected onto the outer peripheral surface 1s of the outer tube 1. In this embodiment, the remaining exhaust pipe portion 5 has a circular shape when viewed in the -Y direction. The minor axis dimension w1 of the remaining exhaust pipe portion 5 is, for example, preferably 2 mm or more and 10 mm or less, and more preferably 3 mm or more and 7 mm or less. The distance d2 between the remaining exhaust pipe portion 5 and the end of the arc tube 10 is preferably 12 mm or more and 35 mm or less, and more preferably 15 mm or more and 30 mm or less.

[0030] The conductive member 8 will be described in detail with reference to FIG. 2. The conductive member 8 is disposed in the sealed space 9. The conductive member 8 has a base 8b located close to the inner electrode 6 and a tip 8e located close to the outer electrode 7 and the remaining portion 5 of the exhaust pipe, and extends from the base 8b to the tip 8e. Because the base 8b is close to the inner electrode 6 and the tip 8e is close to the outer electrode 7, and the conductive member 8 extends from the base 8b to the tip 8e, when a voltage for generating a dielectric barrier discharge is applied between the inner electrode 6 and the outer electrode 7, a linear discharge occurs between the inner electrode 6 and the base 8b, and a linear discharge occurs between the outer electrode 7 and the tip 8e. Because the tip 8e is located closer to the longitudinal center of the outer pipe 1 than the remaining portion 5 of the exhaust pipe, the linear discharge occurs closer to the longitudinal center than the remaining portion 5 of the exhaust pipe.

[0031] The tip 8e is close to the remaining exhaust pipe 5 and the outer electrode 7. Therefore, the conductive member 8 can attract linear discharges toward the remaining exhaust pipe 5. The attracted linear discharges can then escape to the outer electrode 7, which is closer than the remaining exhaust pipe 5. The remaining exhaust pipe 5 accumulates distortion when the exhaust pipe is removed. If linear discharges concentrate on the strained remaining exhaust pipe 5, the discharge energy of the linear discharges will cause cracks in the remaining exhaust pipe 5. However, the outer pipe 1 other than the remaining exhaust pipe 5, to which the linear discharges are directed, does not accumulate distortion. Because the shapes of the outer pipe 1 and the outer electrode 7 are uniform, linear discharges are less likely to concentrate. Therefore, even if the discharge energy from the linear discharges is applied to the outer pipe 1 near the tip 8e, cracks are less likely to occur. The distance d3 between the tip 8e and the remaining exhaust pipe 5 is preferably 10 mm or more and 30 mm or less, and preferably 15 mm or more and 25 mm or less. The tip portion 8 e is preferably closer to the outer electrode 7 than the remaining portion 5 of the exhaust pipe.

[0032] In this embodiment, the tip 8e of the conductive member 8 is not in contact with the outer tube 1, but the tip 8e may be in contact with the outer tube 1. The advantages of the tip 8e not being in contact with the outer tube 1 will be described later. The distance d4 between the tip 8e and the outer electrode 7 closest to the tip 8e is preferably 10 mm or less, and more preferably 6 mm or less. The distance d4 is greater than the thickness t1 of the outer tube 1.

[0033] The base 8b of the conductive member 8 has a ring-shaped portion that wraps around the inner tube 2. In this embodiment, the excimer lamp 100 includes a starting aid 12, which is attached to the ring-shaped portion of the base 8b. In this embodiment, the starting aid 12 is a chain of multiple interconnected rings, with a protruding portion 12p only on the ring at the end of the chain. When the chain hangs down due to gravity, the protruding portion 12p approaches the outer tube 1 (in FIG. 2, the protruding portion 12p is in contact with the outer tube 1). The starting aid 12 is made of a conductor, just like the conductive member 8. When the protruding portion 12p approaches the outer electrode 7, a linear discharge is generated between the protruding portion 12p and the outer electrode 7. When a voltage is applied between the inner electrode 6 and the outer electrode 7 to generate a dielectric barrier discharge, the linear discharge from the starting aid 12 triggers the dielectric barrier discharge. Note that the starting aid 12 is an optional component for the excimer lamp.

[0034] In this embodiment, the conductive member 8 has an anchor end 8a. The anchor end 8a is fixed to a fixing member 11 provided in the sealed space 9. The conductive member 8 is fixed to the inner pipe 2 by the fixing member 11. The fixing member 11 is an annular plate extending radially from the inner pipe 2. The fixing member 11 is welded and fixed to the outer peripheral surface 2s of the inner pipe 2. The fixing member 11 has a through hole that penetrates the plate in the thickness direction, and the conductive member 8 passes through this through hole. The anchor end 8a is bent, which prevents the conductive member 8 from slipping out of the through hole of the fixing member 11. The conductive member 8 has a bent portion 8c midway between the anchor end 8a and the fixing member 11, and the bent portion 8c, together with the bent anchor end 8a, fixes the position of the conductive member 8 relative to the fixing member 11.

[0035] The fixing member 11 is located between the remaining exhaust pipe 5 and the tip 8e. The outer diameter of the annular fixing member 11 is smaller than the inner diameter of the outer tube 1, so there is a gap between the fixing member 11 and the outer tube 1. The sealed space 9 continues to the end region including the remaining exhaust pipe 5, and a dielectric barrier discharge also occurs between the inner electrode 6 and the end region of the outer electrode 7 including the remaining exhaust pipe 5, causing excimer emission. Since the end region also emits light, the emission region of the excimer lamp is expanded.

[0036] The above-described method for fixing the conductive member 8 is merely an example, and other methods may be used to fix the conductive member 8. For example, the base 8b of the conductive member 8 may be welded to the inner tube 2 for fixation.

[0037] The outer tube 1 has a uniform thickness t1. The thickness t1 is preferably 1 mm or more and 4 mm or less, and more preferably 1.5 mm or more and 3 mm or less. The inner tube 2 is composed of two portions with different thicknesses. The first portion 2b is located toward the center in the longitudinal direction and is the thin portion. The second portion 2a is located toward the end in the longitudinal direction and is the thick portion. The position to which the fixing member 11 is welded is the thick second portion 2a. By welding the fixing member 11 to the thick second portion 2a, the fixing member 11 is stably fixed and the welding does not affect the inner tube 2. The thickness t2a of the first portion is preferably 1 mm or more and 4 mm or less, and more preferably 1.5 mm or more and 3 mm or less. The thickness t2b of the second portion is preferably 0.5 mm or more and less than 2 mm, and more preferably 0.8 mm or more and 1.5 mm or less.

[0038] An example of a manufacturing process for an excimer lamp 100 will be described with reference to Figures 3A to 3D. First, an outer tube 1 and an inner tube 2 are prepared. Figure 3A is a diagram showing the outer tube 1. The outer tube 1 has an exhaust pipe 15. The outer tube 1 and the exhaust pipe 15 are made of, for example, quartz. The outer electrode 7 has not yet been attached to the outer peripheral surface 1s of the outer tube 1. Figure 3B is a diagram showing the inner tube 2. A conductive member 8 and a starting aid 12 are attached to the outer peripheral surface 2s, and a fixing member 11 that fixes the conductive member 8 is welded. The inner tube 2 and the fixing member 11 are both made of quartz.

[0039] 3C shows the state in which the inner tube 2 is inserted into the outer tube 1 and the ends of the outer tube 1 and inner tube 2 are joined to form the sealed end 3, thereby forming the sealed space 9. Because the tip 8e does not contact the outer tube 1, when inserting the inner tube 2 into the outer tube 1, the inner wall of the outer tube 1 is unlikely to interfere with the tip 8e, making insertion easier. In addition, the conductive member 8 has a curved portion 8d, which also makes it easier to insert the inner tube 2 into the outer tube 1, as the inner wall of the outer tube 1 is unlikely to interfere with the tip 8e. The radius of curvature of the curved portion 8d is preferably 5 mm or more and 10 mm or less.

[0040] After the sealed space 9 is formed, the gas inside the sealed space 9 is replaced with a light-emitting gas through the exhaust pipe 15. After the replacement with the light-emitting gas, the exhaust pipe 15 is melted and sealed, and the remaining exhaust pipe 5 is formed.

[0041] As shown in Fig. 3D, after the remaining exhaust pipe portion 5 is formed, the outer electrode 7 and the inner electrode 6 are formed. The inner electrode 6 is formed by attaching a sheet-like inner electrode 6 to the inner circumferential surface 2i of the inner pipe 2. The inner electrode 6 may also be formed by depositing a film on the inner circumferential surface 2i.

[0042] The outer electrode 7 is formed by rolling a mesh-like conductive sheet to form a cylindrical mesh, and then covering the arc tube 10 (outer tube 1) shown in FIG. 3D with the cylindrical mesh. To expand the light-emitting area, the cylindrical mesh (outer electrode 7) covers not only the central region of the outer tube 1 but also the end region of the outer tube 1, including the remaining exhaust pipe portion 5. The outer electrode 7 is preferably stretchable so that it can be fitted over the arc tube 10. The outer electrode 7 may also be fixed by hooking it onto the sealed end 3. This allows the outer electrode 7 to be attached to the arc tube 10 while maintaining tension, thereby ensuring close contact with the arc tube 10. Furthermore, since the outer electrode 7 extends to the sealed end 3, a longer light-emitting length can be ensured. In this way, the excimer lamp 100 shown in FIGS. 1 and 2 is completed, which has the outer electrode 7 extending to the end region of the outer tube 1, including the remaining exhaust pipe portion 5. The outer electrode 7 may also be formed by pattern-coating using screen printing or the like.

[0043] The present invention is not limited to the above-described embodiment, and various improvements and modifications can be made without departing from the spirit of the present invention. [Industrial Applicability]

[0044] The excimer lamp 100 of the above-described embodiment is used in the manufacture of semiconductors and liquid crystal panels, but can also be used for other purposes. [Explanation of symbols]

[0045] 1 :Outer tube 1i: Inner surface (of outer tube) 1s: (outer tube) outer surface 2 :Inner tube 2a: Second part (of the inner tube) 2b: First part (of the inner tube) 2i: Inner surface (of inner pipe) 2s: (inner pipe) outer surface 3: Sealed end 5: Remaining part of exhaust pipe 6: Inner electrode 7 :Outer electrode 8: Conductive material 8a: Anchor end (of conductive member) 8b: Base (of conductive member) 8c: Bent portion (of conductive member) 8d: Curved portion (of conductive member) 8e: Tip (of conductive member) 9: Sealed space 10: Arc tube 11: Fixing member 12: Starting aid 12p: Protruding part (of the starting aid) 15: Exhaust pipe 100: Excimer lamp

Claims

1. an arc tube having an outer tube having an exhaust pipe remnant near an end of an outer peripheral surface, and an inner tube inserted into the outer tube, the outer tube and the inner tube being joined at both ends to form a sealed space; an inner electrode disposed inside the inner tube; an outer electrode in contact with the outer peripheral surface of the outer tube, the outer electrode is also formed on the remaining portion of the exhaust pipe; a conductive member provided in the sealed space, the conductive member having a base portion located close to the inner electrode and a tip portion located close to the outer electrode and the remaining portion of the exhaust pipe, and extending from the base portion to the tip portion; An excimer lamp according to claim 1, wherein the tip of the conductive member is located closer to the center of the outer tube in the longitudinal direction than the remaining portion of the exhaust pipe.

2. 2. The excimer lamp according to claim 1, wherein the tip of the conductive member does not contact the outer tube.

3. 3. The excimer lamp according to claim 1, wherein a fixing member for fixing the conductive member is provided in the sealed space.

4. 4. The excimer lamp according to claim 3, wherein the fixing member has an annular shape extending radially from the inner tube and is positioned between the remaining portion of the exhaust pipe and the tip end.

5. the inner tube is composed of a first portion located on a longitudinal center side and having a small thickness, and a second portion located on an end side in the longitudinal direction and having a large thickness, 4. The excimer lamp according to claim 3, wherein the fixing member is located in the second portion.

Images