Excimer lamps and light irradiation device

Abstract

To provide an excimer lamp that is configured to be implementable more simply, can reduce distortion occurring in an arc tube, and can be used for a longer period of time.SOLUTION: An excimer lamp extends in a first direction, and includes a first region and a second region whose tube wall is thicker than the first region on a first section taken along a plane perpendicular to the first direction, and includes a light-emitting tube having translucency to ultraviolet light in which evenness is formed on an outer wall surface thereof by the first region and the second region, a pair of electrodes that face each other via the tube wall of the light-emitting tube in a radial direction of the light-emitting tube, and a light extraction section for extracting ultraviolet light generated inside the light-emitting tube to the outside of the light-emitting tube.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an excimer lamp and a light irradiation device. [Background technology]

[0002] Conventionally, ultraviolet light has been used in the manufacture of semiconductors and liquid crystal panels, and in the generation of ozone for air purification. For example, an excimer lamp as described in the following Patent Document 1 is used as a light source for emitting ultraviolet light. The following Patent Document 1 discloses an excimer lamp in which a reflective film is formed on the inner wall surface of the arc tube in order to efficiently irradiate an object to be irradiated with ultraviolet light emitted from the arc tube. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5633354 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, there has been a demand for higher output excimer lamps as industrial light irradiation devices used in the manufacture of semiconductors and liquid crystal panels, etc. Therefore, the present inventors have investigated ways to increase the output of excimer lamps based on the light irradiation device described in the above Patent Document 1, and have found that the following problems exist. The following will be explained with reference to the drawings.

[0005] Fig. 9A is a schematic diagram of the configuration of a conventional excimer lamp 100 when viewed in the Y direction. Fig. 9B is a schematic diagram of the excimer lamp 100 of Fig. 9A when viewed in the Z direction. As shown in Figs. 9A and 9B, the excimer lamp includes an arc tube 101, a pair of electrodes 102 provided to face an outer wall surface 101a of the arc tube 101, and a reflective film 103 provided on an inner wall surface 101b of the arc tube 101.

[0006] 9A, the direction in which the arc tube 101 of the excimer lamp 100 extends (tube axis direction) is defined as the X direction, the direction in which the electrodes 102 face each other is defined as the Z direction, and the direction perpendicular to the X direction and the Z direction is defined as the Y direction. When expressing a direction, if a distinction is made between positive and negative directions, the direction is described with a positive or negative sign added, such as "+Z direction" and "-Z direction," and when expressing a direction without distinguishing between positive and negative directions, the direction is simply described as "Z direction."

[0007] Arc tube 101 is made of a material (e.g., silica glass) that is transparent to ultraviolet light, and has a light-emitting space 101c formed inside in which light-emitting gas G1 is sealed. As shown in Fig. 9B, electrode 102 is formed in a mesh shape so that ultraviolet light emitted from arc tube 101 can be extracted to the outside of arc tube 101. Note that, although only electrode 102 on the +Z side is shown in Fig. 9B, electrode 102 on the -Z side has the same shape as electrode 102 on the +Z side.

[0008] In the excimer lamp 100, ultraviolet light is generated in the light-emitting space 101c by applying a voltage between the pair of electrodes 102, and the ultraviolet light is emitted outward from the mesh of the electrodes 102. The type and combination of the light-emitting gas G1 to be sealed in the light-emitting space 101c are selected according to the wavelength of the emitted ultraviolet light.

[0009] Ultraviolet light of 200 nm or less, such as that used in the manufacture of semiconductors and liquid crystal panels, can break the bonds between Si and O in the silica glass that is the material of the arc tube 101. Therefore, when the excimer lamp 100 is turned on, the ultraviolet light emitted from the light-emitting space 101c breaks the bonds of the silica glass that constitutes the arc tube 101 one after another, changing the bond angle between Si and O. This causes distortion, and stress is generated on the inner wall surface 101b as if pulling it toward each end side in the X direction.

[0010] The tube wall on the light exit surface 104 side (-Z side) of the arc tube 101 is constantly exposed to ultraviolet light emitted from the light-emitting space 101c when the excimer lamp 100 is turned on. On the other hand, the tube wall on the opposite side (+Z side) of the light exit surface 104 of the arc tube 101 is hardly exposed to ultraviolet light because the ultraviolet light emitted from the arc tube 101 is reflected toward the light exit surface 104 side by the reflective film 103 formed on the inner wall surface 101b. In this way, distortion occurs in the -Z side tube wall due to irradiation with ultraviolet light, while distortion does not occur in the +Z side tube wall due to irradiation with ultraviolet light, causing the entire arc tube to deform convexly toward the +Z side.

[0011] Fig. 10 is a drawing of the excimer lamp 100 deformed by ultraviolet light when viewed in the Y direction. The ultraviolet light emitted from the light-emitting space 101c causes the arc tube 101 to deform as described above, and as shown in Fig. 10, the arc tube 101 deforms so that the entire tube becomes convex toward the +Z side in accordance with the deformation of the -Z side wall surface. When the arc tube 101 deforms, the distance between the light exit surface 104 and the irradiation area varies depending on the position, resulting in uneven irradiation. Note that the excimer lamp 100 in Fig. 10 is depicted as being more deformed than it actually is, in order to make the change easier to understand.

[0012] The above-mentioned Patent Document 1 discloses an excimer lamp having an arc tube that is curved in advance so that distortion caused by irradiation with ultraviolet light causes the wall surface of the arc tube to become nearly flat, in order to prevent uneven irradiation of ultraviolet light due to deformation of the arc tube and damage to the arc tube 101.

[0013] However, it is difficult to accurately predict the degree of distortion that will occur due to irradiation with ultraviolet light, and advanced processing techniques are required to bend the arc tube to the desired curvature during the manufacturing process.

[0014] In the above explanation, the explanation is based on the excimer lamp 100 provided with the reflective film 103, but naturally, deformation of the arc tube 101 due to irradiation with ultraviolet light can also occur in an excimer lamp that is not provided with the reflective film 103. In other words, the pattern of deformation that occurs in the arc tube 101 differs depending on whether the reflective film 103 is provided or not, but in either case, deformation occurs in the arc tube 101 due to irradiation with ultraviolet light. For this reason, the problem of uneven irradiation can also occur in an excimer lamp that is not provided with the reflective film 103.

[0015] Furthermore, the above-mentioned problem exists in that the direction and part of the arc tube 101 that deforms differs depending on the respective device configurations, such as when a reflective member is provided on the outside of the arc tube 101 or when a cooling mechanism is provided.

[0016] In view of the above problems, an object of the present invention is to provide an excimer lamp and a light irradiation device that can be used for a longer period of time by reducing distortion caused in an arc tube with a configuration that can be more easily implemented. [Means for solving the problem]

[0017] The excimer lamp of the present invention is an arc tube that is stretched in a first direction, and that includes a first region and a second region whose tube wall is thicker than the first region in a first cross section when cut along a plane perpendicular to the first direction, and that has an outer wall surface that is uneven due to the first region and the second region, and that is transparent to ultraviolet light; a pair of electrodes facing each other in a radial direction of the arc tube via a tube wall of the arc tube; The lamp is characterized by comprising a light extraction section for extracting the ultraviolet light generated within the light emitting tube to the outside of the light emitting tube.

[0018] Furthermore, the excimer lamp is The first cross section of the arc tube may have a rectangular shape, and the light extraction portion may be formed on at least one of the wall surfaces of the arc tube that are aligned along different planes.

[0019] Furthermore, in the above excimer lamp, The light extraction portion may be formed with both the first region and the second region.

[0020] In addition, the above excimer lamp is A reflective film may be formed on a wall surface of the arc tube other than the light extraction portion.

[0021] The second region can be easily and stably produced by adjusting the mold for producing the arc tube, melting and cutting a part of the tube wall of the produced arc tube, etc. Note that this method for producing the arc tube is merely one example, and other production methods may be adopted.

[0022] As described above, the distortion induced in the light-emitting tube by irradiation with ultraviolet light is caused by the difference in expansion between the inner wall surface side, where the severing of Si-O bonds is significantly more prevalent, and the outer wall surface side, where such severing is less likely to occur than on the inner wall surface side.

[0023] In the present invention, from the viewpoint of increasing the strength against bending of the entire arc tube due to expansion of the inner wall surface and against external shocks and forces, at least the outer wall surface is formed with an uneven shape. However, this does not exclude the formation of an uneven shape on the inner wall surface.

[0024] Here, the distortion of the arc tube caused by irradiation with ultraviolet light is caused by the breaking of the bonds between Si and O in the silica glass, as mentioned above. However, it is known that the bonds between Si and O broken by irradiation with ultraviolet light are re-bonded by the repair action of the OH groups contained in the silica glass. Furthermore, this repair action becomes more pronounced as the temperature of the silica glass increases and the internal atomic movement becomes more active. In other words, the higher the temperature of the arc tube, the more pronounced the repair action effect of the OH groups becomes, and the distortion caused by the breakage of Si and O is alleviated.

[0025] A light emitting tube having a thin wall region formed in a part thereof has a smaller heat capacity than a light emitting tube having no thin wall region, and therefore the rate of temperature rise immediately after lighting is improved. Therefore, a light emitting tube having a thin wall region formed in a part thereof reaches a high temperature immediately after lighting. That is, compared to light emitting tubes having a conventional configuration, a light emitting tube having such a configuration is more likely to maintain the state before the distortion occurs, since the distortion repair action starts to occur immediately after lighting starts even if distortion occurs due to irradiation with ultraviolet light. For example, when the downtime of an excimer lamp (the time from when the lamp is turned off to when it is turned on again) is relatively long and the lamp is turned on again after the downtime, if the light emitting tube has a thin wall region formed in a part thereof, the distortion repair action starts to occur immediately after the lamp is turned on again.

[0026] An arc tube with a thin portion of the tube wall can be produced, for example, by melting and cutting a portion of an arc tube produced in a conventional manner. In this case, the portion of the tube wall that has been melted and cut to be thin corresponds to the first region, and the portion that has not been processed in any way corresponds to the second region.

[0027] The arc tube of the above configuration extends in a first direction, and a first region and a second region are formed in a first cross section. By forming the first region and the second region, the arc tube of the above configuration has improved strength against deformation caused by bending in the first direction. Therefore, the arc tube of the above configuration is less likely to deform due to irradiation with ultraviolet light than arc tubes of conventional configurations.

[0028] In addition, the amount of heat accumulated in the arc tube with a thick wall region is greater than that in the arc tube without a thick wall region, and the heat retention effect is improved. Therefore, the arc tube with a thick wall region maintains a high temperature state for a longer period even after the light is turned off, and the above-mentioned repair effect continues for a long period of time. That is, the arc tube with this configuration is more likely to return to the state before the distortion occurred, compared to the arc tube with the conventional configuration, even if distortion occurs due to irradiation with ultraviolet light. For example, in the case where the rest time of the excimer lamp is relatively short and the on-off operation of the excimer lamp is repeated in a short time, the heat retention effect continues and distortion is less likely to occur in the arc tube with a thick wall region.

[0029] As described above, an arc tube having an outer wall surface formed with unevenness by the first and second regions is more likely to exhibit the effect of repairing distortion in the arc tube even when the excimer lamp is used for a relatively long period of downtime, or when the downtime is relatively short and the flashing operation is repeated in a short period of time.

[0030] Furthermore, the difference between the thickness of the thinnest part of the tube wall and the thickness of the thickest part of the tube wall is preferably 3% or more, more preferably 5% or more, and even more preferably 10% or more, based on the thickness of the thickest part of the tube wall. Note that it is not necessarily the case that the thinnest part of the tube wall is the first region and the thickest part of the tube wall is the second region.

[0031] An arc tube having some parts with thicker walls can be produced, for example, by pouring molten glass into a mold capable of producing arc tubes of a desired shape. In this case, the part with the relatively thinner wall corresponds to the first region, and the part with the relatively thicker wall corresponds to the second region.

[0032] The relationship between the first region and the second region described above is not classified according to the shape before and after processing or the absolute thickness, but according to the relative thickness formed on the tube wall of the arc tube after manufacture.

[0033] The above excimer lamps are When looking at the first cross section, the first region may be formed in the center of the wall surface on which the light extraction portion is formed, and the second region may be formed near the boundary between the reflective film and the light extraction portion.

[0034] In this specification, the term "near the boundary" is intended to include the region from the boundary between the reflective film and the light extraction portion to a position spaced a distance equivalent to the average thickness of the entire light-emitting tube.

[0035] The above excimer lamps are When looking at the first cross section, the second region may be formed in the center of the wall surface on which the light extraction portion is formed, and the first region may be formed near the boundary between the reflective film and the light extraction portion.

[0036] By making or processing the tube wall of the arc tube in the center of the wall surface where the light extraction portion is formed thicker than other portions, when the first and second regions are formed, the heat retention effect of the light extraction portion, which is irradiated with a relatively large amount of ultraviolet light, can be improved and a higher temperature can be easily reached. In other words, the arc tube of the above configuration can obtain a higher effect of the repair action for a long period of time in the portion where distortion is relatively likely to occur, and therefore distortion of the entire arc tube can be further reduced.

[0037] In addition, since the light extraction part is irradiated with ultraviolet light, distortion occurs more significantly, but since the region where the reflective film is formed receives less ultraviolet light, distortion does not occur as much as in the light extraction part. Therefore, the vicinity of the boundary between the reflective film and the light extraction part is the boundary between the region where distortion occurs and the region where distortion is unlikely to occur, and so it is prone to localized strong stress and breakage.

[0038] By making or processing the vicinity of the boundary between the reflective film of the tube wall of the arc tube and the light extraction part thinner, in the case where the first region and the second region are formed, the temperature rise rate of the part where strong local stress is applied can be increased. In other words, in the arc tube of the above configuration, the effect of the above repair action appears early in the part where strong local stress is applied, so that damage caused by distortion that occurs especially immediately after the start of lighting can be suppressed.

[0039] In addition, in accordance with the above, by making or processing the tube wall of the light-emitting tube thinner at the midpoint of the ends of the reflective film, when the first region and the second region are formed, it is possible to suppress damage caused by distortion that occurs in the portion relatively prone to distortion, particularly immediately after lighting begins.

[0040] Furthermore, when the first and second regions are formed by manufacturing or processing the arc tube wall so that the area near the boundary between the reflective film and the light extraction portion is thicker, the above-mentioned repair effect can be achieved for a longer period of time in areas that are prone to strong localized stress, thereby further reducing the load on those areas of the arc tube.

[0041] In the above excimer lamp, When looking at the first cross section, the wall surface of the light-emitting tube facing the light extraction portion includes a third region and a fourth region in which the tube wall is thicker than the third region, and the third region and the fourth region may form an unevenness on the outer wall surface.

[0042] With the above-mentioned configuration, the above-mentioned irregularities are formed on the multiple wall surfaces, so that the strength of the arc tube against distortion is further increased.

[0043] Furthermore, the excimer lamp is In the wall surface of the arc tube facing the light extraction portion when viewed in the first cross section, the third region may be formed in the center, and the fourth region may be formed at both ends.

[0044] In addition, the above excimer lamp is In the wall surface of the arc tube facing the light extraction portion when viewed in the first cross section, the fourth region may be formed in the center, and the third region may be formed at both ends.

[0045] According to the above-mentioned configuration, the arc tube can reduce distortion caused by irradiation with ultraviolet light, and the strength of the portion that comes into contact with a regulating body provided for reducing distortion caused by irradiation with ultraviolet light, as described below, is increased.

[0046] The above excimer lamps are The tube wall of the light emitting tube may be configured so that at least a portion of the thickness gradually changes.

[0047] As used herein, "gradual change in thickness" refers to a thickness that increases stepwise multiple times from the thinnest part to the thickest part, or a thickness that increases continuously and monotonically.

[0048] The light irradiation device of the present invention comprises: The above excimer lamp, The light emitting tube further includes a restricting body that protrudes toward a tube wall that faces the light extraction portion of the light emitting tube and is disposed so that a tip portion of the restricting body is adjacent to the tube wall.

[0049] In this specification, the term "close proximity" is used to mean a separation distance of 2 mm or less. Effect of the Invention

[0050] According to the present invention, it is possible to realize an excimer lamp and a light irradiation device that can be used for a longer period of time by reducing distortion occurring in the light emitting tube with a configuration that can be more simply implemented. [Brief description of the drawings]

[0051] [Figure 1] 2 is a schematic cross-sectional view of an embodiment of a light irradiation device when viewed in the Y direction. FIG. [Diagram 2]2 is a schematic cross-sectional view of an excimer lamp according to an embodiment when viewed in the Y direction. [Diagram 3] 1 is a schematic diagram of an excimer lamp according to an embodiment when viewed in the Z direction. [Figure 4] 2 is a schematic cross-sectional view of an excimer lamp according to an embodiment when viewed in the X direction. [Diagram 5] 11 is an enlarged cross-sectional view of the periphery of a regulating body of the light irradiation device as viewed in the X direction. FIG. [Figure 6] 2 is a schematic cross-sectional view of an excimer lamp according to an embodiment when viewed in the X direction. [Figure 7] 2 is a schematic cross-sectional view of an excimer lamp according to an embodiment when viewed in the X direction. [Figure 8] 2 is a schematic cross-sectional view of an excimer lamp according to an embodiment when viewed in the X direction. [Figure 9A] 1 is a schematic diagram showing the configuration of a conventional excimer lamp as viewed in the Y direction. [Figure 9B] 9B is a schematic diagram of the excimer lamp of FIG. 9A when viewed in the Z direction. [Figure 10] This is a drawing of an excimer lamp deformed by ultraviolet light, viewed in the Y direction. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0052] The excimer lamp and the light irradiation device of the present invention will be described below with reference to the drawings. 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.

[0053] [First embodiment] Fig. 1 is a schematic cross-sectional view of a first embodiment of a light irradiation device 1 as viewed in the Y direction. As shown in Fig. 1, the light irradiation device 1 of the first embodiment includes an excimer lamp 2, a regulating body 3, and a transport mechanism 4 on which an irradiation target W1 is placed.

[0054] First, the configuration of the excimer lamp 2 will be described. Fig. 2 is a schematic cross-sectional view of the excimer lamp 2 in the first embodiment when viewed in the Y direction. Fig. 3 is a schematic drawing of the excimer lamp 2 in the first embodiment when viewed in the Z direction. Fig. 4 is a schematic cross-sectional view of the excimer lamp 2 in one embodiment when viewed in the X direction. As shown in Figs. 2 and 4, the excimer lamp 2 includes an arc tube 10, a pair of electrodes (11, 12), a reflective film 13, and a light extraction portion 14.

[0055] 2, the direction in which the excimer lamp 2 extends (tube axis direction) is the X direction (first direction), the direction in which the pair of electrodes (11, 12) face each other is the Z direction, and the direction perpendicular to the X direction and Z direction is the Y direction (second direction). When expressing a direction, if positive and negative directions need to be distinguished, the direction is described with a positive and negative sign, such as "+Z direction" and "-Z direction," and when expressing a direction without distinguishing between positive and negative directions, the direction is simply described as "Z direction."

[0056] The light emitting tube 10 is made of a material (e.g., silica glass) that is translucent to the ultraviolet light L1, and extends in the X direction, and has a rectangular shape when cut in the YZ plane (first cross section) as shown in Fig. 2. The light emitting tube 10 is provided with a light emitting space 10c inside which a light emitting gas G1 is sealed.

[0057] In the excimer lamp 2 in the first embodiment, a light emitting gas G1 containing xenon (Xe) gas is sealed in the light emitting space 10c of the light emitting tube 10 so as to emit ultraviolet light L1 with a peak wavelength of 172 nm. Note that this configuration is merely an example, and the type of light emitting gas G1 sealed in the light emitting tube 10 is arbitrarily selected according to the purpose of use of the light irradiation device 1, i.e., the wavelength of the ultraviolet light L1 to be emitted.

[0058] 4, when viewed from a first cross section, the arc tube 10 in the first embodiment has a first region 10p and a second region 10q whose tube wall is thicker than the first region 10p formed in the tube wall on the -Z side, and a third region 10r and a fourth region 10s whose tube wall is thicker than the third region 10r formed in the tube wall on the +Z side.

[0059] In the first embodiment, in the circumferential direction of the first cross section of the arc tube 10, a second region 10q is formed at a middle position C1 of the end 13a of the reflective film 13, and a first region 10p is formed in the vicinity of the boundary 10d between the reflective film 13 and the light extraction portion 14. Then, in the circumferential direction of the first cross section of the arc tube 10, a third region 10r is formed in the center on the wall surface on the +Z side, and fourth regions 10s are formed on both ends.

[0060] As shown in FIG. 4, in the first embodiment, the second region 10q and the fourth region 10s have thicker tube walls than the first region 10p and the third region 10r, and are formed so that the thickness gradually changes in the circumferential direction of the light-emitting tube 10.

[0061] The electrodes (11, 12) are mesh-like metal films formed on the outer wall surface 10a of the arc tube 10 in the Z direction so as to face each other in the radial direction via the arc tube 10, and are connected to a power supply device (not shown) to apply a voltage required for lighting. Any method for applying the voltage may be used, but in the first embodiment, a pulsed voltage of a desired level is periodically applied between the electrodes (11, 12) to generate ultraviolet light L1 in the light-emitting space 10c.

[0062] The electrodes (11, 12) are, for example, metal wires woven into a mesh shape, or metal films formed by evaporating a metal material onto the masked outer wall surface 10a of the arc tube 10 or by applying a metal paste. The electrode 11 formed on the outer wall surface 10a of the tube wall on which the reflective film 13 is formed does not need to be mesh-shaped, and may be a solid electrode over a portion or the entirety. Examples of materials constituting the electrodes (11, 12) include gold, silver, copper, platinum, etc.

[0063] Furthermore, one of the electrodes (11, 12) may be disposed inside the arc tube 10. Here, being disposed inside the arc tube 10 includes the case where one of the electrodes is disposed in the light-emitting space 10c, and the case where one of the electrodes is disposed inside the inner tube wall in an arc tube that has an inner tube wall and an outer tube wall and in which the light-emitting space 10c is formed in a region sandwiched between the inner tube wall and the outer tube wall so as to have a cylindrical shape.

[0064] The reflective film 13 is formed on the inner wall surface 10b of the tube wall on the +Z side of the light emitting tube 10 and on the inner wall surface 10b of the tube wall opposing in the Y direction. As shown in Fig. 4, the reflective film 13 reflects the ultraviolet light L1 that is generated in the light emitting space 10c and travels in a direction different from the light extraction part 14 so that the ultraviolet light L1 travels toward the light extraction part 14.

[0065] The reflective film 13 may be a sintered film of metal oxide formed by applying a suspension containing particulate silica (SiO2), alumina (Al2O3), or the like, and baking the suspension.

[0066] The reflective film 13 may be formed on the outer wall surface 10a of the light emitting tube 10, or a reflective member may be provided as a separate member without providing the reflective film 13. Furthermore, if there is no particular need to deal with the ultraviolet light L1 emitted in a direction different from the irradiation target W1, a reflective film or reflective member may not be provided.

[0067] The light extraction section 14 is a part of the arc tube 10 that is configured by the tube wall on the -Z side of the arc tube 10 and that extracts the ultraviolet light L1 generated in the light-emitting space 10c to the outside of the arc tube 10. Note that the light extraction section 14 in the first embodiment is provided with a mesh-shaped electrode 12, as shown in Fig. 3. Therefore, the ultraviolet light L1 generated in the light-emitting space 10c of the arc tube 10 is emitted to the outside of the arc tube 10 via the light extraction section 14 and the mesh of the electrode 12.

[0068] FIG. 5 is an enlarged cross-sectional view of the periphery of the regulating body 3 of the light irradiation device 1 when viewed in the X direction. As shown in FIG. 5, the regulating body 3 protrudes so as to approach the arc tube 10. A roller 3a is provided at the tip, and the roller 3a is arranged so as to be close to the fourth region 10s formed on the tube wall on the +Z side. When distortion occurs as shown in FIG. 10, the roller 3a comes into contact with the arc tube 10 to regulate the difference in the distance between the light extraction part 14 and the irradiation object W1 depending on the position, thereby suppressing uneven irradiation on the irradiation object W1. In addition, by arranging the second region 10q or the fourth region 10s, in which the tube wall of the arc tube 10 is thick, so as to be close to the regulating body 3, the resistance to stress load when coming into contact with the regulating body 3 is increased, and damage to the arc tube 10 is further suppressed.

[0069] In the light irradiation device 1 of the first embodiment, a plurality of regulating bodies 3 may be provided in one light irradiation device 1, and the tip portion where the roller 3a is provided may be bifurcated, or may be trifurcated or more. According to this configuration, the excimer lamp 2 in which distortion has occurred is supported at a plurality of points. Therefore, in the light irradiation device 1 with this configuration, the force applied to the light emitting tube 10 is dispersed compared to the case where the light irradiation device 1 is supported at one point, and damage to the light emitting tube 10 is suppressed.

[0070] The arc tube 10 included in the light irradiation device 1 configured as above has improved strength against deformation caused by bending in the X direction due to the uneven shape formed by the presence of the first region 10p and the second region 10q, compared to conventional arc tubes. Therefore, the light irradiation device 1 configured as above can be used for a longer period of time, since damage to the arc tube 10 is suppressed, compared to conventional configurations.

[0071] Furthermore, the excimer lamp 2 included in the light irradiation device 1 of the first embodiment can enhance the heat retention effect of the light extraction portion 14, which is irradiated with a relatively large amount of ultraviolet light L1. In other words, the arc tube 10 having the above configuration is configured such that the effect of the above-mentioned repair action is relatively enhanced in the portion where distortion is relatively likely to occur, and therefore distortion of the entire arc tube can be further reduced.

[0072] As shown in FIG. 4, the light emitting tube 10 of the first embodiment is formed with the first region 10p and the second region 10q whose tube wall is thicker than the first region 10p. However, the tube wall may be formed with a further region whose thickness is different from that of the first region 10p and the second region 10q.

[0073] Furthermore, the second region 10q only needs to have a thicker tube wall than the first region 10p, and does not need to be convex on either the inside or outside of the arc tube 10 as shown in Fig. 4. For example, the second region 10q may have a flat surface on the inner wall surface 10b side and a convex shape only on the outer wall surface 10a side.

[0074] Furthermore, these points are similar to those of the third region 10r and the fourth region 10s in the tube wall on the +Z side. In the first embodiment, the shapes and positional relationship of the first region 10p and the second region 10q and the shapes and positional relationship of the third region 10r and the fourth region 10s in the Y direction are illustrated as being the same, but these shapes and positional relationships do not have to be the same.

[0075] [Second embodiment] The configuration of the second embodiment of the light irradiation device of the present invention will be described, focusing on the differences from the first embodiment.

[0076] Fig. 6 is a schematic cross-sectional view of an excimer lamp 2 in the second embodiment when viewed in the X direction. As shown in Fig. 6, the arc tube 10 in the second embodiment has a first region 10p and a second region 10q whose tube wall is thicker than the first region 10p in a tube wall facing each other in the Z direction when viewed in a first cross section. In the second embodiment, the first region 10p is formed at a position C1 in the middle of the end 13a of the reflective film 13, and the second region 10q is formed near the boundary 10d between the reflective film 13 and the light extraction portion 14 in the circumferential direction of the first cross section of the arc tube 10.

[0077] In the second embodiment, the second region 10q and the fourth region 10s have thicker tube walls than the first region 10p and the third region 10r due to the formation of convex portions on the outer wall surface 10a of the light-emitting tube 10.

[0078] The excimer lamp 2 included in the light irradiation device 1 of the second embodiment can improve the heat retention effect in the vicinity of the boundary 10d between the reflective film 13 and the light extraction portion 14. In other words, the arc tube 10 having the above configuration can achieve the above-mentioned repair action more effectively and for a longer period of time in the vicinity of the boundary 10d where strong local stress is likely to be applied, and therefore the load generated in the vicinity of the boundary 10d of the arc tube 10 can be further reduced.

[0079] [Third embodiment] The configuration of the third embodiment of the light irradiation device of the present invention will be described, focusing on the differences from the first and second embodiments.

[0080] Fig. 7 is a schematic cross-sectional view of an excimer lamp 2 in the third embodiment when viewed in the X direction. As shown in Fig. 7, the arc tube 10 in the third embodiment has a first region 10p and a second region 10q whose tube wall is thicker than the first region 10p, formed by cutting a part of the tube wall on the -Z side.

[0081] The excimer lamp 2 included in the light irradiation device 1 of the third embodiment can improve the temperature rise rate of the light extraction part 14, which is irradiated with a relatively large amount of ultraviolet light L1. That is, the arc tube 10 of the above configuration is prevented from being damaged in a part relatively susceptible to distortion due to irradiation with ultraviolet light L1, particularly immediately after lighting is started.

[0082] [Fourth embodiment] The configuration of the fourth embodiment of the light irradiation device of the present invention will be described, focusing on the differences from the first, second and third embodiments.

[0083] Fig. 8 is a schematic cross-sectional view of an excimer lamp 2 in the fourth embodiment when viewed in the X direction. As shown in Fig. 8, the arc tube 10 in the fourth embodiment has a first region 10p and a second region 10q whose tube wall is thicker than the first region 10p, formed by cutting a part of the tube wall on the -Z side.

[0084] The excimer lamp 2 included in the light irradiation device 1 of the fourth embodiment can improve the rate of temperature rise near the boundary 10d between the reflective film 13 and the light extraction portion 14, where strong local stress is applied. In other words, in the arc tube 10 of the above configuration, the above-mentioned repair effect appears early near the boundary 10d, where strong local stress is applied, and therefore damage caused by distortion that occurs especially immediately after lighting is started is suppressed.

[0085] [Another embodiment] Another embodiment will be described below.

[0086] <1> In each of the above-described embodiments, a configuration has been described in which the shape of the first cross section of the arc tube 10 is rectangular. However, the shape of the first cross section of the arc tube 10 does not have to be rectangular and may be, for example, a circular, oval, elliptical, polygonal, or any other shape.

[0087] <2> The configurations of the light irradiation device 1 and the excimer lamp 2 described above are merely examples, and the present invention is not limited to the respective configurations shown in the drawings. [Explanation of symbols]

[0088] 1 : Light irradiation device 2: Excimer lamp 3: Regulatory body 3a: Laura 4: Transport mechanism 10: Arc tube 10a: Exterior wall 10b: Inner wall 10c: Luminous Space 10d : Boundary 10p: First area 10q: Second area 10r: Third area 10s: Fourth area 11,12 : Electrode 13: Reflective film 13a: End 14: Light extraction section 100: Excimer lamp 101: Arc tube 101a: External wall surface 101b: Inner wall 101c: Luminous space 102 : Electrode 103: Reflective film 104: Light exit surface G1: Luminous gas L1: Ultraviolet light W1: Irradiation target

Claims

1. an arc tube that is stretched in a first direction, and that includes a first region and a second region whose tube wall is thicker than the first region in a first cross section when cut along a plane perpendicular to the first direction, and that has an outer wall surface that is uneven due to the first region and the second region, and that is transparent to ultraviolet light; a pair of electrodes facing each other in a radial direction of the arc tube via a tube wall of the arc tube; and a light extraction section for extracting ultraviolet light generated within the light emitting tube to the outside of the light emitting tube.

2. 2. The excimer lamp according to claim 1, wherein the shape of the first cross section of the light-emitting tube is rectangular, and the light extraction portion is formed on at least one of the wall surfaces of the light-emitting tube that are aligned along different planes.

3. 3. The excimer lamp according to claim 2, wherein both the first region and the second region are formed in the light extraction portion.

4. 3. The excimer lamp according to claim 2, wherein a reflective film is formed on a wall surface of the arc tube different from the light extraction portion.

5. The excimer lamp of claim 4, characterized in that, when viewed in the first cross section, the first region is formed in the center of the wall surface on which the light extraction portion is formed, and the second region is formed near the boundary between the reflective film and the light extraction portion.

6. The excimer lamp described in claim 4, characterized in that, when viewed in the first cross section, the second region is formed in the center of the wall surface on which the light extraction portion is formed, and the first region is formed near the boundary between the reflective film and the light extraction portion.

7. The excimer lamp described in claim 2, characterized in that, when viewed in the first cross section, the wall surface of the light-emitting tube facing the light extraction portion includes a third region and a fourth region in which the tube wall is thicker than the third region, and an unevenness is formed on the outer wall surface by the third region and the fourth region.

8. The excimer lamp according to claim 7, characterized in that, when viewed in the first cross section, the wall surface of the light-emitting tube facing the light extraction portion has the third region formed in the center and the fourth region formed at both ends.

9. The excimer lamp according to claim 7, characterized in that, when viewed in the first cross section, the wall surface of the light-emitting tube facing the light extraction portion has the fourth region formed in the center and the third region formed at both ends.

10. 2. The excimer lamp according to claim 1, wherein, when viewed in the first cross section, at least a portion of the tube wall of the arc tube has a thickness that gradually changes.

11. An excimer lamp according to any one of claims 1 to 10, a restricting body that protrudes toward a tube wall that faces the light extraction portion of the light-emitting tube and is disposed so that a tip portion thereof is adjacent to the tube wall.

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