Gas laser device and method for manufacturing electronic device

Abstract

The gas laser device (100) comprises a housing (30), a window holder (300a, 300b), a window (31a, 31b) and a sealing member (400a, 400b). The window holder (300a, 300b) further comprises an extension surface (315), which is located on the reflection direction side of the reflected light reflected by the window in the light traveling toward the window via the opening (305), and extends continuously with the end surface (303) in a direction away from the window, and is irradiated with the reflected light from the window. The line (602) is located at a position where the optical axis of the reflected light is symmetrically folded at the irradiation position of the reflected light on the extension surface (315) with reference to a reference line passing through the irradiation position of the reflected light on the extension surface (315) and perpendicular to the extension surface (315). The line (602) crosses the normal line (600) of the window from the outer peripheral side of the window toward the central axis side of the window in the direction from the extension surface (315) toward the window.

Description

Technical Field

[0001] The present disclosure relates to a gas laser device and a method for manufacturing an electronic device. Background Art

[0002] In recent years, in semiconductor exposure devices, as semiconductor integrated circuits become smaller and more highly integrated, there is a demand for improved resolution. Therefore, the wavelength of light emitted from an exposure light source has been shortened. For example, as a gas laser device for exposure, a KrF excimer laser device that outputs a laser with a wavelength of about 248nm and an ArF excimer laser device that outputs a laser with a wavelength of about 193nm are used.

[0003] The spectral line width of the natural oscillation light of the KrF excimer laser device and the ArF excimer laser device is relatively wide, about 350pm to 400pm. Therefore, when the projection lens is composed of a material that allows ultraviolet light such as KrF and ArF lasers to pass through, chromatic aberration sometimes occurs. As a result, the resolution may be reduced. Therefore, it is necessary to narrow the spectral line width of the laser output from the gas laser device to a level where chromatic aberration can be ignored. Therefore, in order to narrow the spectral line width, a narrowing module (Line Narrow Module: LNM) containing narrowing elements (etalon, grating, etc.) is sometimes provided in the laser resonator of the gas laser device. Hereinafter, a gas laser device with a narrowed spectral line width is referred to as a narrowed gas laser device.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 1-231017

[0007] Patent Document 2: Japanese Patent Application Laid-Open No. 5-3354

[0008] Patent Document 3: Japanese Patent Application Laid-Open No. 8-148738 Summary of the invention

[0009] A gas laser device according to one embodiment of the present invention comprises: a housing including an internal space for generating light by excitation of laser gas and a hole for emitting light from the internal space; a cylindrical window holder arranged on the housing and including a hollow portion for transmitting light emitted from the hole; a window for transmitting light traveling in the hollow portion and being held by the window holder in a state where a surface for light incidence is inclined relative to an optical axis of the light traveling in the hollow portion; and an annular sealing member arranged to fit tightly between the window and an end face of the window holder opposite to the window, and The window holder is configured to surround an opening surrounded by an end face that is connected to a hollow portion, and further includes an extension surface, the extension surface being located on the reflection direction side of reflected light reflected by the window in the light traveling toward the window through the opening, and extending continuously with the end face in a direction away from the window, and being irradiated with the reflected light from the window, a line located at a position where the optical axis of the reflected light is symmetrically folded at the irradiation position with respect to a reference line that passes through the irradiation position of the reflected light on the extension surface and is perpendicular to the extension surface, and a normal line that crosses the window from the outer peripheral side of the window toward the central axis side of the window in the direction from the extension surface toward the window.

[0010] In addition, a method for manufacturing an electronic device according to one embodiment of the present invention includes the following steps: causing laser light emitted from a gas laser device to be incident on an exposure device, exposing the laser light on a photosensitive substrate in the exposure device to manufacture the electronic device, the gas laser device comprising: a housing including an internal space for generating light by excitation of laser gas and a hole for emitting light from the internal space; a cylindrical window holder, which is arranged in the housing and includes a hollow portion for passing light emitted from the hole; a window that transmits light traveling in the hollow portion and is held by the window holder in a state in which a surface for light incidence is inclined relative to an optical axis of the light traveling in the hollow portion; and an annular sealing member, which is arranged so as to The window holder is tightly fitted between the window and the end face of the window holder opposite to the window, and is configured to surround an opening surrounded by the end face that is connected to the hollow portion. The window holder also includes an extension surface, which is located on the reflection direction side of the reflected light reflected by the window in the light traveling toward the window through the opening, and extends continuously with the end face in the direction away from the window. The reflected light from the window is irradiated on a line located at a position where the optical axis of the reflected light is symmetrically returned at the irradiation position with respect to a reference line that passes through the irradiation position of the reflected light on the extension surface and is perpendicular to the extension surface, and crosses the normal to the window from the outer peripheral side of the window toward the central axis side of the window in the direction from the extension surface toward the window. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Hereinafter, several embodiments of the present disclosure will be described as simple examples with reference to the accompanying drawings.

[0012] Figure 1 It is a schematic diagram showing an example of the overall schematic configuration of an electronic device manufacturing apparatus.

[0013] Figure 2 This is a schematic diagram showing an example of the overall schematic configuration of a gas laser device.

[0014] Figure 3 It is a diagram showing a schematic structural example of the window and the periphery of the window holder on the output coupling mirror side in a comparative example.

[0015] Figure 4 It is a diagram showing a schematic structural example of the window and the window holder surrounding the output narrowband module in a comparative example.

[0016] Figure 5 This is a diagram showing a schematic structural example of the window on the output coupling mirror side and the periphery of the window holder in the first embodiment.

[0017] Figure 6 This is a schematic perspective view of the window holder when viewed from the end surface side of the window holder.

[0018] Figure 7 This is a diagram showing a schematic structural example of the window and the periphery of the window holder on the output coupling mirror side in the second embodiment.

[0019] Figure 8 This is a diagram showing a schematic structural example of the window and the window holder surrounding in a modified example of the second embodiment.

[0020] Fig. 9 This is a diagram showing a schematic structural example of the window and the window holder surroundings in another modified example of the second embodiment.

[0021] Fig.10 This is a diagram showing a schematic structural example of the window and the periphery of the window holder on the output coupling mirror side in the third embodiment.

[0022] Fig.11 This is a diagram showing a schematic structural example of the window and the periphery of the window holder on the output coupling mirror side in the fourth embodiment.

[0023] Fig.12 This is a diagram showing a schematic structural example of the window and the periphery of the window holder on the output coupling mirror side in the fifth embodiment.

[0024] Fig.13 yes Fig.12 A schematic diagram of a region surrounded by a solid circle in the recess is shown. DETAILED DESCRIPTION

[0025] 1. Description of an electronic device manufacturing apparatus used in an exposure process of an electronic device

[0026] 2. Description of the gas laser device of the comparative example

[0027] 2.1 Structure

[0028] 2.2 Actions

[0029] 2.3 Topics

[0030] 3. Description of the Gas Laser Device of Embodiment 1

[0031] 3.1 Structure

[0032] 3.2 Functionality

[0033] 3.3 Effects

[0034] 4. Description of the Gas Laser Device of Embodiment 2

[0035] 4.1 Structure

[0036] 4.2 Effects

[0037] 5. Description of the gas laser device according to Embodiment 3

[0038] 5.1 Structure

[0039] 5.2 Effects

[0040] 6. Description of the Gas Laser Device of Embodiment 4

[0041] 6.1 Structure

[0042] 6.2 Action / Effect

[0043] 7. Description of the gas laser device according to the fifth embodiment

[0044] 7.1 Structure

[0045] 7.2 Action / Effect

[0046] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0047] The embodiments described below illustrate several examples of the present disclosure and do not limit the content of the present disclosure. In addition, the structures and actions described in each embodiment are not necessarily all necessary for the structures and actions of the present disclosure. In addition, the same reference numerals are marked on the same structural elements and repeated descriptions are omitted.

[0048] 1. Description of an electronic device manufacturing apparatus used in an exposure process of an electronic device

[0049] Figure 1 1 is a schematic diagram showing an overall schematic configuration example of an electronic device manufacturing apparatus used in an exposure process of the electronic device. Figure 1As shown, the manufacturing device used in the exposure process includes a gas laser device 100 and an exposure device 200. The exposure device 200 includes an illumination optical system 210 and a projection optical system 220, and the illumination optical system 210 includes a plurality of mirrors 211, 212, and 213. The illumination optical system 210 illuminates the mask pattern of the mask stage RT using the laser light incident from the gas laser device 100. The projection optical system 220 performs reduced projection of the laser light after passing through the mask so that it is imaged on a workpiece (not shown) arranged on the workpiece stage WT. The workpiece is a photosensitive substrate such as a semiconductor wafer coated with a photoresist. The exposure device 200 causes the mask stage RT and the workpiece stage WT to move in parallel synchronously, thereby exposing the workpiece to the laser light reflecting the mask pattern. By transferring the device pattern on the semiconductor wafer through the above exposure process, a semiconductor device as an electronic device can be manufactured.

[0050] 2. Description of the gas laser device of the comparative example

[0051] 2.1 Structure

[0052] A gas laser device 100 of a comparative example will be described. The comparative examples of the present disclosure are examples that the applicant recognizes as being known only to the applicant, and are not examples that the applicant acknowledges as being publicly known.

[0053] Figure 2 Schematic diagram showing an overall schematic structure example of the gas laser device 100 of this example. Figure 2 As shown, the gas laser device 100 of this example includes a housing 10, a laser oscillator LO, a wavelength measurement module 20 and a processor 70 as main structures. The gas laser device 100 of this example is, for example, an ArF excimer laser device using a mixed gas containing argon (Ar), fluorine (F2) and neon (Ne). In this case, the gas laser device 100 emits a pulse laser with a central wavelength of about 193nm. In addition, the gas laser device 100 may also be a gas laser device other than the ArF excimer laser device, for example, it may also be a KrF excimer laser device using a mixed gas containing krypton (Kr), fluorine (F2) and neon (Ne). In this case, the gas laser device 100 emits a pulse laser with a central wavelength of about 248nm. A mixed gas containing Ar, F2 and Ne as a laser medium, and a mixed gas containing Kr, F2 and Ne as a laser medium are sometimes referred to as laser gas.

[0054] The processor 70 of the present disclosure is a processing device including a storage device storing a control program and a CPU executing the control program. The processor 70 is specially configured or programmed to perform various processes included in the present disclosure. The processor 70 controls several structures of the gas laser device 100. In addition, the processor 70 controls the gas laser device 100 as a whole.

[0055] The laser oscillator LO includes a cavity device CH, a charger BC, a narrowband module 60 and an output coupling mirror OC as main structures.

[0056] The chamber device CH has a shell 30, a pair of windows 31a, 31b, a pair of window holders 300a, 300b described later, a pair of sealing parts 400a, 400b described later, a pair of fixing units 500a, 500b described later, a pair of electrodes 32a, 32b, an insulating part 33, a pulse power module 35, an electrode holder part 36, a cross flow fan 38 and a motor 38M as main structures.

[0057] The window 31a and the window 31b are provided at mutually opposing positions in the housing 30. The window 31a is located at one end side in the direction of travel of the laser light in the housing 30, and the window 31b is located at the other end side in the direction of travel of the laser light in the housing 30. As described later, in the gas laser device 100, light oscillates on an optical path including the housing 30 to emit laser light, and therefore, the laser light generated in the internal space of the housing 30 is emitted to the outside of the housing 30 via the window 31a and the window 31b. Each of the windows 31a and 31b is inclined at a Brewster angle with respect to the direction of travel of the laser light to suppress reflection of P-polarized light of the laser light.

[0058] The housing 30 includes an internal space in which light is generated by the excitation of the above-mentioned laser gas. The laser gas is supplied to the internal space of the housing 30 from a laser gas supply source (not shown) disposed in the housing 10 via a pipe (not shown). In this example, the gas laser device 100 is an ArF excimer laser device, and therefore, for example, a mixed gas containing Ar, F2, and Ne is supplied from the laser gas supply source to the internal space of the housing 30. In addition, when the gas laser device 100 is a KrF excimer laser, for example, a mixed gas containing Kr, F2, and Ne is supplied from the laser gas supply source to the internal space of the housing 30. The above-mentioned light generated by the excitation of the laser gas is emitted from the hole 30a described later of the housing 30, and travels to the windows 31a and 31b through the hollow parts of the cylindrical window holders 300a and 300b, respectively.

[0059] The length direction of a pair of electrodes 32a, 32b is along the traveling direction of the laser, and the pair of electrodes 32a, 32b are arranged opposite to each other in the internal space of the housing 30. The space between the electrode 32a and the electrode 32b in the housing 30 is between the window 31a and the window 31b. Each electrode 32a, 32b is a discharge electrode for exciting the laser medium by glow discharge. In this example, the electrode 32a is a cathode and the electrode 32b is an anode.

[0060] An opening is formed in the housing 30, and the opening is blocked by an insulating portion 33 formed of an insulator. The electrode 32a is supported by the insulating portion 33. A feedthrough hole 34 composed of a conductive member is embedded in the insulating portion 33. The feedthrough hole 34 applies the voltage supplied from the pulse power module 35 to the electrode 32a. The electrode 32b is supported by an electrode holder portion 36 and is electrically connected to the electrode holder portion 36. The electrode holder portion 36 is electrically connected to the housing 30 via wiring not shown.

[0061] The pulse power module 35 is connected to a charger BC disposed outside the housing 30. The charger BC is a DC power supply device that charges a capacitor (not shown) provided in the pulse power module 35 at a predetermined voltage. The pulse power module 35 includes a switch controlled by the processor 70. When the switch is turned from off to on, the pulse power module 35 boosts the voltage applied from the charger BC to generate a pulse-shaped high voltage, and applies the high voltage to the pair of electrodes 32a, 32b.

[0062] A cross-flow fan 38 is disposed in the internal space of the housing 30 on the side opposite to the electrode 32b side with respect to the electrode holder portion 36. The space in the internal space of the housing 30 where the cross-flow fan 38 is disposed is connected to the space between a pair of electrodes 32a and 32b in the internal space of the housing 30. Therefore, the cross-flow fan 38 rotates, thereby circulating the laser gas enclosed in the internal space of the housing 30 in a predetermined direction. The cross-flow fan 38 is connected to a motor 38M disposed outside the housing 30. The motor 38M rotates, thereby rotating the cross-flow fan 38. The motor 38M is turned on, off, and the rotation speed is adjusted by the control of the processor 70. Therefore, the processor 70 can adjust the circulation speed of the laser gas circulating in the internal space of the housing 30 by controlling the motor 38M.

[0063] Furthermore, a heat exchanger (not shown) is disposed next to cross flow fan 38. At least a portion of the laser gas circulated by cross flow fan 38 passes through the heat exchanger, and the temperature of the laser gas is adjusted by the heat exchanger.

[0064] The optical path tube 51 is connected to the above-mentioned one end side where the window 31a is provided in the housing 30. The output coupling mirror OC is provided on the above-mentioned one end side based on the housing 30, and is arranged in the internal space of the optical path tube 51. The output coupling mirror OC is an optical element for incident laser light emitted from the window 31a, and transmits a part of the light emitted from the window 31a, and reflects the other part and returns to the internal space of the housing 30 through the window 31a. The output coupling mirror OC is composed of, for example, an element in which a dielectric multilayer film is formed on a substrate of calcium fluoride. A film that partially reflects the laser light may also be formed on the surface of the output coupling mirror OC.

[0065] The optical path tube 52 is connected to the other end side of the housing 30 where the window 31b is provided. The narrowband module 60 is connected to the optical path tube 52. Therefore, the narrowband module 60 is provided on the other end side with reference to the housing 30, and is provided on the side opposite to the output coupling mirror OC with reference to the housing 30. The narrowband module 60 includes a housing 61, a grating 62, and prisms 63 and 64. An opening is formed in the housing 61, and the internal space of the housing 61 and the internal space of the optical path tube 52 are connected through the opening.

[0066] The grating 62 and the prisms 63 and 64 are arranged in the internal space of the housing 61. The grating 62 and the prisms 63 and 64 are optical elements for the laser light emitted from the window 31b to be incident. The grating 62 is configured in a Littrow manner so that the incident angle and the diffraction angle of the laser light are roughly consistent. In this example, the grating 62 can be a step grating blazed for a wavelength of about 193nm. In addition, the grating 62 is fixed to the housing 61 and does not move relative to the housing 61.

[0067] At least one of the prisms 63 and 64 is fixed on a rotating table (not shown) arranged in the internal space of the housing 61. The prism fixed on the rotating table among the prisms 63 and 64 rotates slightly, thereby adjusting the incident angle of the light incident on the grating 62. By adjusting the incident angle of the light incident on the grating 62, the wavelength of the light reflected by the grating 62 and incident on the cavity device CH is adjusted. Therefore, the light emitted from the window 31b of the housing 30 is reflected on the grating 62 via the prisms 63 and 64, thereby adjusting the wavelength of the light returned to the housing 30 to the desired wavelength. Each of the prisms 63 and 64 is made of calcium fluoride, for example. In addition, the number of prisms arranged in the narrowband module 60 is 2 in this example, but it can also be 1, or 3 or more.

[0068] The laser resonator is formed by the output coupling mirror OC and the grating 62 provided across the housing 30, and the housing 30 is arranged on the optical path of the laser resonator. Therefore, the light emitted from the internal space of the housing 30 through the hole of the housing 30 described later reciprocates between the grating 62 and the output coupling mirror OC of the narrowband module 60 through the windows 31a, 31b and the prisms 63, 64. The reciprocating light is amplified each time it passes through the laser gain space between the electrode 32a and the electrode 32b. A part of the amplified light passes through the output coupling mirror OC through the window 31a and is emitted as a pulsed laser.

[0069] The wavelength measurement module 20 is arranged on the optical path of the pulse laser emitted from the output coupling mirror OC of the laser oscillator LO. The wavelength measurement module 20 includes a housing 21, a beam splitter 22, and a wavelength monitor 23. The housing 21 is connected to the optical path tube 51. An opening is formed in the housing 21, and the internal space of the housing 21 and the internal space of the optical path tube 51 are connected through the opening. The beam splitter 22 and the wavelength monitor 23 are arranged in the internal space of the housing 21. The beam splitter 22 and the wavelength monitor 23 are optical elements for the pulse laser emitted from the output coupling mirror OC to be incident.

[0070] The beam splitter 22 transmits the pulse laser emitted from the laser oscillator LO with high transmittance and reflects a part of the pulse laser toward the light receiving surface of the wavelength monitor 23. The wavelength monitor 23 detects the wavelength of the pulse laser incident on the light receiving surface and outputs the detected wavelength data to the processor 70.

[0071] An opening is formed on the side opposite to the side connected to the optical tube 51 in the housing 21 of the wavelength measurement module 20, and an optical tube 53 is connected to surround the opening. Therefore, the internal space of the optical tube 51, the internal space of the housing 21, and the internal space of the optical tube 53 are connected to each other. The optical tube 53 is connected to the housing 10. A laser emission window OW is provided at a position surrounded by the optical tube 53 in the housing 10. Therefore, the light that has passed through the beam splitter 22 of the wavelength measurement module 20 is emitted from the laser emission window OW to the outside of the housing 10 via the optical tube 53.

[0072] The internal space of the optical tubes 51, 52, 53 and the housings 21 and 61 is filled with a purge gas. The purge gas contains an inert gas such as high-purity nitrogen with less impurities such as oxygen. The purge gas is supplied to the internal space of the optical tubes 51, 52, 53 and the housings 21 and 61 from a purge gas supply source (not shown) arranged outside the housing 10 through a pipe (not shown).

[0073] In addition, an exhaust device (not shown) for exhausting laser gas exhausted from the internal space of the housing 30 of the chamber device CH is arranged in the internal space of the housing 10. The exhaust device removes F2 gas from the gas exhausted from the internal space of the housing 30 through a halogen filter and discharges the gas into the housing 10.

[0074] Next, refer to Figure 3 The structures of the window 31a and the window holder 300a in the comparative example will be described. Figure 3 3 is a diagram showing a schematic structural example of a window 31a and a window holder 300a in a comparative example. Figure 3 In FIG. 3 , the window 31a and the window holder 300a are represented by a vertical cross section. Figure 3In FIG. 1 , light traveling from the internal space of the housing 30 to the window 31 a via the hole 30 a , the hollow portion 301 , and the opening 305 of the housing 30 is indicated by a solid arrow F1 .

[0075] The window holder 300a is cylindrical and is located between the above-mentioned one end of the housing 30 and the window 31a. Figure 3 In the embodiment, one end of the window holder 300a is connected to the wall surface of the housing 30, and the other end of the window holder 300a is located on the window 31a side.

[0076] The cylindrical window holder 300a includes a hollow portion 301 and an end surface 303 located at the other end of the window holder 300a.

[0077] The hollow portion 301 is connected to the internal space of the shell 30 via the hole 30a of the shell 30. In addition, the hollow portion 301 is connected to the opening 305 located at the end surface 303. Light traveling from the internal space of the shell 30 to the output coupling mirror OC via the hole 30a, the opening 305 and the window 31a of the shell 30 passes through the hollow portion 301. In addition, light traveling from the output coupling mirror OC to the internal space of the shell 30 in the opposite direction to the above also passes through the hollow portion 301. Therefore, the opening 305 is an exit port for light to be emitted to the output coupling mirror OC, and is also an entrance port for light to be incident to the hollow portion 301.

[0078] The end face 303 is arranged opposite to the window 31a. In addition, the end face 303 is arranged parallel to the surface of the opposite window 31a. Hereinafter, this surface is sometimes referred to as the laser gas side surface in contact with the laser gas. Like the end face 303, the opening 305 is also arranged parallel to the surface of the window 31a. The end face 303 is a plane. The window 31a is located in the projection area plane of the end face 303 projected toward the window 31a along a straight line orthogonal to the end face 303.

[0079] The window 31a is a parallel plane substrate. The window 31a is made of calcium fluoride. The window 31a can also be a parallel wedge-shaped substrate. In addition, the window 31a can also be made of a component with high transmittance in the ultraviolet region, such as magnesium fluoride, fused quartz or synthetic quartz.

[0080] The window 31a is arranged so that the light traveling in the hollow portion 301 is incident at a predetermined angle. The angle is an angle near the Brewster angle, for example, 55° to 61°. The window 31a is held by the window holder 300a in a state where the surface of the window 31a into which the light is incident is tilted relative to the optical axis of the light indicated by the solid arrow F1 traveling in the hollow portion 301.

[0081] like Figure 3As shown in FIG. 1 , a sealing member 400a and a fixing unit 500a are arranged around the window 31a and the window holder 300a. Next, the structures of the annular sealing member 400a and the fixing unit 500a will be described.

[0082] The sealing member 400a is arranged so as to be sandwiched between the end face 303 and the window 31a by the end face 303 and the window 31a. The sealing member 400a is arranged so as to surround the central axis C of the window 31a and the opening 305 of the end face 303. Therefore, the inner diameter of the sealing member 400a is larger than the diameter of the opening 305 of the end face 303. In addition, the outer diameter of the sealing member 400a is substantially the same as the outer diameter of the window 31a, and the sealing member 400a is arranged at the outer periphery of the surface of the window 31a that contacts the laser gas. The sealing member 400a is an O-ring made of a resin such as nitrile rubber. In addition, the sealing member 400a may be arranged so as to surround the opening 305 in the end face 303, the outer diameter of the sealing member 400a may be smaller than the outer diameter of the window 31a, or the sealing member 400a may be arranged between the opening 305 and the outer periphery of the window 31a.

[0083] The sealing member 400a is in close contact with the surface of the window 31a and the end face 303 of the window holder 300a. Therefore, it can be understood that the window holder 300a holds the window 31a at the end face 303 via the sealing member 400a. The sealing member 400a seals between the surface of the window 31a and the end face 303 of the window holder 300a by being in close contact. As a result, the laser gas is sealed in the internal space of the housing 30, the hollow portion 301, and the space between the end face 303 and the window 31a.

[0084] The fixing unit 500 a fixes the sealing member 400 a and the window 31 a to the window holder 300 a. The fixing unit 500 a includes a ring member 501 and a fixing member 503 .

[0085] The ring member 501 is arranged on the surface of the window 31a on the side opposite to the sealing member 400a, and is arranged to surround the central axis C of the window 31a. Hereinafter, this surface is sometimes referred to as the purge gas side surface in contact with the purge gas. The inner diameter of the ring member 501 is substantially the same as the inner diameter of the sealing member 400a, and the outer diameter of the ring member 501 is substantially the same as the outer diameter of the sealing member 400a. In addition, the ring member 501 is arranged on the outer periphery of the surface of the window 31a in contact with the purge gas. Therefore, the ring member 501 is arranged on the side opposite to the sealing member 400a with the window 31a as a reference, and the window 31a is arranged between the sealing member 400a and the ring member 501. The central axes of the ring member 501, the window 31a and the sealing member 400a are arranged to be coaxial.

[0086] The fixing component 503 is cylindrical. The inner diameter of the fixing component 503 is substantially the same as the outer diameter of each of the window 31a, the sealing component 400a and the ring component 501. The fixing component 503 surrounds the outer peripheral surfaces of the window 31a, the sealing component 400a and the ring component 501 in the entire circumference, and abuts against each outer peripheral surface. The fixing component 503 can also fit closely with each outer peripheral surface. The central axis of the fixing component 503 is located at a position coaxial with the central axis C of the window 31a. The fixing component 503 that surrounds the outer peripheral surfaces of the window 31a, the sealing component 400a and the ring component 501 in the entire circumference is installed on the end surface 303 at one end of the fixing component 503.

[0087] The fixing member 503 includes an annular inner flange portion 505 disposed at the other end of the fixing member 503. The inner flange portion 505 is disposed over the entire circumference of the inner circumferential surface of the fixing member 503. In addition, the inner flange portion 505 extends from the inner circumferential surface of the fixing member 503 toward the center of the fixing member 503 in the radial direction of the fixing member 503. The inner diameter of the inner flange portion 505 is substantially the same as the inner diameter of the ring member 501.

[0088] When the fixing member 503 is mounted on the end face 303, the inner flange portion 505 presses the ring member 501 toward the window 31a. As a result, the window 31a is pressed toward the end face 303 via the sealing member 400a, and is fixed in the axial and radial directions of the window 31a. In addition, the fixing member 503 fixes the window 31a in the radial direction of the window 31a by abutting against the outer peripheral surface of the window 31a.

[0089] In addition, the sealing member 400a is elastically deformed by the pressing, and the close contact surface of the sealing member 400a, the window 31a and the end face 303 is wider than before the pressing due to the elastic deformation. As a result, the sealing member 400a is more closely attached than before the pressing, and the laser gas side surface of the window 31a and the end face 303 of the window holder 300a are further sealed by the close contact.

[0090] The window holder 300a and the ring member 501 are made of metal. The metal is, for example, stainless steel such as SUS304, SUS316 or SUS303. In addition, the end face 303 of the window holder 300a facing the window 31a and the contact surface of the ring member 501 that contacts the window 31a are mirror-polished.

[0091] The structures of the window 31b, the window holder 300b, the sealing member 400b and the fixing unit 500b are the same as the structures of the window 31a, the window holder 300a, the sealing member 400a and the fixing unit 500a. Figure 4As shown, the configuration of the window holder 300b relative to the housing 30 is the same as the configuration of the window holder 300a relative to the housing 30, except that the window holder 300b is configured on the other end side of the housing 30 and the window holder 300b is configured upside down with respect to the window holder 300a with respect to the optical axis of the light indicated by the arrow F1, so detailed description is omitted.

[0092] 2.2 Action

[0093] Next, the operation of the gas laser device 100 according to the comparative example will be described.

[0094] Before the gas laser device 100 emits laser light, purge gas is filled from a purge gas supply source (not shown) into the inner spaces of the optical path tubes 51, 52, 53 and the inner spaces of the housings 21 and 61. In addition, laser gas is supplied from a laser gas supply source (not shown) into the inner space of the housing 30. When the laser gas is supplied, the processor 70 controls the motor 38M to rotate the cross flow fan 38, and the laser gas is circulated by the rotation of the cross flow fan 38.

[0095] When the gas laser device 100 emits laser light, the processor 70 controls the switches in the charger BC and the pulse power module 35 to apply a high voltage between the electrode 32a and the electrode 32b. When a high voltage is applied between the electrodes 32a and 32b, the insulation between the electrodes 32a and 32b is destroyed and discharge occurs. The laser medium contained in the laser gas between the electrodes 32a and 32b becomes excited by the energy of the discharge, and emits natural emission light when returning to the ground state. Part of the light is ultraviolet light, and the light emitted from the housing 30 passes through the window 31b via the hollow portion 301 and the opening 305 in the window holder 300b. The light after passing through the window 31b is expanded in the direction of light travel through the prisms 63 and 64 and guided to the grating 62. The wavelength of light is dispersed every time it passes through each prism 63 and 64. In addition, the light is incident on the grating 62 at a specified angle for diffraction, and the light of a specified wavelength is reflected at the grating 62 at the same reflection angle as the incident angle. The light reflected by the grating 62 propagates from the window 31b again to the inner space of the housing 30 through the opening 305 of the window holder 300b, the hollow part 301 and the hole 30a of the housing 30 via the prisms 63 and 64. The light propagating to the inner space of the housing 30 is narrow-banded by the narrow-banded module 60. The laser medium in the excited state generates stimulated emission by the narrow-banded light, and the light is amplified. The light is emitted from the hole 30a of the housing 30, passes through the window 31a via the hollow part 301 and the opening 305 in the window holder 300a, and travels toward the output coupling mirror OC. A part of the light passes through the output coupling mirror OC, and another part of the light is reflected by the output coupling mirror OC and propagates from the window 31a via the opening 305 of the window holder 300a, the hollow part 301 and the hole 30a of the housing 30 to the inner space of the housing 30. The light propagating to the inner space of the housing 30 passes through the window 31b and the prisms 63 and 64 toward the grating 62 as described above. In this way, light of a predetermined wavelength reciprocates between the grating 62 and the output coupling mirror OC. Therefore, the light is amplified and laser oscillation occurs. Then, a part of the laser light passes through the output coupling mirror OC and is emitted toward the exposure device 200 from the laser emission window OW.

[0096] In addition, a portion of the laser light after passing through the output coupling mirror OC is reflected by the beam splitter 22. The reflected laser light is received by the wavelength monitor 23, and the wavelength monitor 23 outputs a signal based on the intensity of the energy of the received laser light to the processor 70. The processor 70 controls the charger BC and the pulse power module 35 according to the signal to adjust the power of the emitted laser light.

[0097] 2.3 Topics

[0098] In the gas laser device 100 of the comparative example, Figure 3As shown by the arrow F1, light travels from the inner space of the housing 30 to the window 31a via the hole 30a, the hollow portion 301 and the opening 305 of the housing 30. When the light passes through the window 31a, part of the light is reflected by the surface of the window 31a. Figure 3 In the figure, as shown by arrow F2, the reflected light travels from the surface of the window 31a to the end face 303 by reflection, and as shown by arrow F3 of a solid line, is reflected toward the window 31a through the end face 303. Next, the reflected light sometimes passes through the window 31a and travels toward a component arranged on the outer peripheral side of the window 31a. The outer peripheral side includes the outer peripheral surface of the window 31a and the outer peripheral side of the laser gas side surface and the purge gas side surface of the window 31a. In addition, the components are components configured not to hinder the travel of light that travels back and forth in the laser resonator through the window 31a, and are the sealing component 400a, the ring component 501, and the fixing component 503. Here, as shown by arrow F4 of a solid line, the reflected light sometimes passes through the window 31a and travels toward the ring component 501. Here, the reflected light does not travel toward the entire surface of the ring component 501 that abuts against the purge gas side surface of the window 31a, but travels toward a portion of the surface of the ring component 501 located in the reflection side area in the surface of the ring component 501. When the ring member 501 is observed from the front and the ring member 501 is divided into semicircular arc shapes at the top and bottom, a part of the surface roughly corresponds to the bottom of the semicircular arc at the bottom. In addition, the reflected light is sometimes reflected by the part of the surface of the ring member 501, as shown by the solid arrow F5, and passes through the window 31a to the sealing member 400a. In this case, the reflected light does not travel toward the entire close-fitting surface of the sealing member 400a that is in close contact with the laser gas side surface of the window 31a, but travels toward a part of the close-fitting surface of the sealing member 400a located in the above-mentioned reflection side area in the close-fitting surface of the sealing member 400a. The part of the close-fitting surface is opposite to the part of the surface of the ring member 501 that is irradiated with the reflected light.

[0099] Here, for some reason, the reflectivity of the surface of the window 31a is higher than the assumed state, or the intensity of the reflected light is higher than the assumed state. In this case, there is a concern that the sealing member 400a, which is irradiated with reflected light for a predetermined time or longer, deteriorates earlier than the pre-assumed period, and the service life of the sealing member 400a is shorter than the pre-assumed period. When the service life of the sealing member 400a is shortened, the usable period of the gas laser device 100, which represents the interval from the maintenance of the gas laser device 100 to the next maintenance after the maintenance, may be shorter than the pre-assumed period.

[0100] Here, the window holder 300a side is described. However, on the window holder 300b side, part of the light traveling from the housing 30 to the window 31b via the window holder 300b is also reflected by the surface of the window 31b. As described above, the window holder 300b is arranged upside down with respect to the window holder 300a, so the reflection direction of the window 31b is the opposite side to the reflection direction of the window 31a. As described above, the reflected light may travel to the sealing member 400b on the window holder 300b side via the end face 303 of the window holder 300b and the ring member 501 in the fixing unit 500b on the window holder 300b side. Therefore, similar to the sealing member 400a, there is a concern that the sealing member 400b may also deteriorate earlier than the period assumed in advance, and the service life of the sealing member 400b may be shorter than the period assumed in advance. When the service life of the sealing member 400b is shortened, the usable period of the gas laser device 100 may be shorter than the period assumed in advance.

[0101] Therefore, in the following embodiment, a gas laser device 100 is exemplified in which degradation of the sealing members 400 a and 400 b is suppressed, thereby preventing the usable period from being shorter than a period assumed in advance.

[0102] In addition, in the following embodiments and modifications of the embodiments, the window 31a and the window holder 300a on the output coupling mirror OC side are used for description, but the window 31b and the window holder 300b on the grating 62 side can also obtain the same structure, function, and effect as the window 31a and the window holder 300a.

[0103] 3. Description of the Gas Laser Device of Embodiment 1

[0104] Next, the gas laser device 100 according to Embodiment 1 will be described. The same components as those described above are denoted by the same reference numerals, and the duplicate description will be omitted unless otherwise specified.

[0105] 3.1 Structure

[0106] Figure 5 31a and the window holder 300a in the present embodiment. Figure 5 In FIG. 1 , the window 31a and the window holder 300a are shown using a vertical cross section. Figure 6 This is a schematic perspective view of the window holder 300a according to the present embodiment when viewed from the end surface 303 side of the window holder 300a.

[0107] In the gas laser device 100 of the present embodiment, the structures of the window holders 300a and 300b are mainly different from those of the window holders 300a and 300b of the comparative example. In the present embodiment, the structure of the window holder 300a is the same as that of the window holder 300b. In addition, in the present embodiment, as in the comparative example, the arrangement of the window holder 300b of the present embodiment relative to the housing 30 is the same as that of the window holder 300a of the present embodiment relative to the housing 30, except that the window holder 300b is arranged at the other end side of the housing 30 and the window holder 300b is arranged upside down with respect to the window holder 300a of the present embodiment with reference to the optical axis of the light indicated by the arrow F1. Next, the difference between the window holder 300a and the window holder 300a of the comparative example will be described using the window holder 300a.

[0108] While the end surface 303 of the window holder 300a in the comparative example is entirely a flat surface parallel to the surface of the window 31a, the recessed portion 310 is continuous with the end surface 303 of the window holder 300a in the present embodiment.

[0109] The recessed portion 310 is continuous with the region surrounded by the sealing member 400a in the end surface 303. The recessed portion 310 is located on the reflection direction side of the light reflected by the window 31a among the light traveling from the opening 305 toward the window 31a in the region. Figure 5 In FIG. 3 , the reflected light is indicated by a solid arrow F12 . The recessed portion 310 is recessed from the end surface 303 toward the hollow portion 301 and communicates with the hollow portion 301 .

[0110] The opening 311 of the recessed portion 310 is continuous with the opening 305 and is surrounded by the sealing member 400a. The opening 311 is parallel to the window 31a.

[0111] The pair of side surfaces 313 of the recessed portion 310 are planar inner wall surfaces in the recessed portion 310 and are orthogonal to and opposed to the end surface 303. The pair of side surfaces 313 are continuous with the end surface 303 and the inner peripheral surface of the window holder 300a in the hollow portion 301.

[0112] The recessed portion 310 includes an extension surface 315 extending in a direction away from the window 31a continuously from the end surface 303. The extension surface 315 is located on the reflection direction side of the reflected light from the window 31a and is a planar bottom surface of the recessed portion 310 directly irradiated with the reflected light from the window 31a.

[0113] The extension surface 315 includes one end 315a continuous with the end surface 303 and the other end 315b continuous with the inner peripheral surface of the window holder 300a in the hollow portion 301. Therefore, it can be understood that the one end 315a is located at a position away from the optical axis of the light indicated by the solid arrow F1, and the other end 315b is located at a position close to the optical axis of the light indicated by the solid arrow F1.

[0114] The inclination angle of the extension surface 315 relative to the window 31a is larger than the inclination angle of the end surface 303 relative to the window 31a. The inclination angle of the extension surface 315 relative to the window 31a is the angle formed by three points: the other end 315b of the extension surface 315, the intersection of the straight line passing through the other end 315b and one end 315a of the extension surface 315 and the laser gas side surface of the window 31a, and the center of the laser gas side surface of the window 31a. The intersection point may also be the intersection point of the straight line and the expansion area when the laser gas side surface is expanded in the plane direction of the laser gas side surface. The end surface 303 is arranged parallel to the window 31a, so the inclination angle of the end surface 303 relative to the window 31a is zero. Therefore, it can be understood that the other end 315b side of the extension surface 315 is located at a position inclined in a direction away from the window 31a, that is, counterclockwise, with the one end 315a of the extension surface 315 as the center. In addition, it can be understood that the distance between the extension surface 315 and the window 31a gradually increases from the one end 315a toward the other end 315b. The distance between the one end 315a of the extension surface 315 and the window 31a is the same as the distance between the end surface 303 and the window 31a in the direction along the normal line 600 described later, but is shorter than the distance between the other end 315b of the extension surface 315 and the window 31a. In addition, the extension surface 315 does not extend parallel to the optical axis of the light indicated by the solid arrow F1, but is also inclined relative to the optical axis.

[0115] Similar to the window holder 300a of the comparative example, the window holder 300a of the present embodiment is made of a metal such as stainless steel. Therefore, the extension surface 315 reflects the reflected light traveling from the window 31a toward the extension surface 315. In addition, when the extension surface 315 is inclined as described above, the extension surface 315 reflects the reflected light traveling from the window 31a toward the extension surface 315 toward the window 31a via the inner side of the sealing member 400a. In the present embodiment, the extension surface 315 reflects the reflected light toward the window 31a in the direction from the extension surface 315 toward the window 31a, so that the reflected light from the window 31a is incident on the window 31a from the outer peripheral side of the window 31a toward the central axis C side of the window 31a across the normal 600 of the window 31a. Figure 5In the figure, the solid arrow F13 represents the reflected light reflected by the extension surface 315 and incident on the window 31a. The normal line 600 is a line passing through the extension surface 315 among the multiple normal lines in the laser gas side surface of the window 31a. The intersection of the normal line 600 and the extension surface 315 is located between the intersection of the irradiation position of the reflected light in the extension surface 315 and the normal line of the window 31a at the irradiation position of the light indicated by the arrow F1 and the extension surface 315. Here, a line passing through the irradiation position of the reflected light on the extension surface 315 and the window 31a is set as a reference line. In the present embodiment, the reference line is a line perpendicular to the extension surface 315. In addition, an imaginary line located at a position where the optical axis of the reflected light is symmetrically folded at the irradiation position of the reflected light on the extension surface 315 with respect to the reference line is set as line 602. In Figure 5 , the solid line of the arrow F13 indicating the reflected light overlaps a portion of the imaginary line 602. Similar to the reflected light indicated by the solid arrow F13, the imaginary line 602 can be understood as being located at a position that crosses the normal line 600 of the window 31a from the outer peripheral side of the window 31a toward the central axis side of the window 31a in the direction from the extension surface 315 toward the window 31a.

[0116] like Figure 6 As shown, the width of the extension surface 315 is shorter than the maximum width of the rounded rectangular opening 305 and is the same as the length of the straight line portion in the rounded rectangular opening 305. The width of the extension surface 315 is also the width of the opening 311 and is also the distance between the pair of side surfaces 313. The extension surface 315 is, for example, a rectangular shape such as a rectangular shape. The extension surface 315 is orthogonal to the pair of side surfaces 313.

[0117] 3.2 Function

[0118] Next, the function of the extension surface 315 in this embodiment will be described.

[0119] In the gas laser device 100 of this embodiment, similarly to the gas laser device 100 of the comparative example, Figure 5 As shown by the arrow F1, light travels from the inner space of the housing 30 to the window 31a via the hole 30a, the hollow portion 301 and the opening 305 of the housing 30. When the light passes through the window 31a, part of the light is reflected by the surface of the window 31a as in the comparative example. Figure 5In the figure, as shown by the solid arrow F12, the reflected light travels from the surface of the window 31a toward the recessed portion 310. In addition, the reflected light travels from the opening 311 of the recessed portion 310 toward the inside of the recessed portion 310, and directly travels toward the extension surface 315 of the recessed portion 310. The light indicated by the solid arrow F1 and the reflected light indicated by the solid arrow F12 pass through the inner side of the sealing member 400a. The laser gas side surface of the window 31a is inclined relative to the direction of the optical axis of the light indicated by the solid arrow F1, the end face 303 is arranged parallel to the window 31a, and the side face 313 is orthogonal to the end face 303. Therefore, when the reflected light indicated by the solid arrow F12 is observed along the light indicated by the solid arrow F1, the reflected light indicated by the arrow F12 passes between the pair of side faces 313 and travels toward the extension surface 315, and is suppressed from traveling from the window 31a toward the side face 313.

[0120] The imaginary line 602 crosses the normal line 600 of the window 31a from the outer peripheral side of the window 31a toward the central axis side of the window 31a in the direction from the extension surface 315 toward the window 31a. Thus, when the extension surface 315 reflects the reflected light, the reflected light is suppressed from traveling toward a portion of the surface of the ring member 501 and a portion of the inner peripheral surface of the fixing member 503. In addition, in the present embodiment, the window holder 300a including the extension surface 315 is made of metal, and therefore, the reflected light is reflected by the extension surface 315. In addition, the extension surface 315 is arranged obliquely as described above, and therefore, the reflected light is reflected toward the window 31a by the extension surface 315, and enters the window 31a through the inner side of the sealing member 400a. In addition, the extension surface 315 is arranged obliquely as described above, and therefore, as shown by the arrow F13, the reflected light travels from the outer peripheral side of the window 31a toward the central axis C side of the window 31a in the direction from the extension surface 315 toward the window 31a, crossing the normal line 600, and passes through the window 31a. The traveling direction of the reflected light is the opposite side region side. The opposite side region is located on the side opposite to the reflection side region located on the reflection direction side of the reflected light reflected by the window 31a, based on the irradiation position of the light indicated by the arrow F1 in the laser gas side surface of the window 31a. In this way, the reflected light traveling from the laser gas side surface of the window 31a to the purge gas side surface is suppressed from traveling from the central axis C side of the window 31a toward the outer peripheral side of the window 31a through the extension surface 315 in the reflection side region. Therefore, compared with the case where the extension surface 315 is not formed, the reflected light is suppressed from traveling toward a portion of the surface of the ring component 501 located in the reflection side region and a portion of the inner peripheral surface of the fixing component 503. A portion of the surface of the ring component 501 located in the reflection side region and a portion of the inner peripheral surface of the fixing component 503 are located on the side opposite to the reflection direction of the reflected light. In addition, the reflected light indicated by the solid arrow F13 is reflected by the extension surface 315 as described above, and therefore, is suppressed from traveling from the extension surface 315 toward the side surface 313.

[0121] 3.3 Effects

[0122] In the gas laser device 100 of this embodiment, the sealing member 400a is arranged to be closely attached to the window 31a and the end surface 303 of the window holder 300a, and is arranged to surround the opening 305. The extension surface 315 is located on the reflection direction side of the reflected light from the window 31a, and extends continuously with the end surface 303 in the direction away from the window 31a, and is irradiated with the reflected light. The imaginary line 602 crosses the normal line 600 of the window 31a from the outer peripheral side of the window 31a toward the central axis side of the window 31a in the direction from the extension surface 315 toward the window 31a.

[0123] On the outer peripheral side of the window 31a, a component is generally arranged in a manner not to hinder the light passing through the window 31a. In this embodiment, a ring component 501 and a fixing component 503 are arranged. In this state, when the extension surface 315 reflects the reflected light, the reflected light is suppressed from traveling toward a portion of the surface of the ring component 501 and a portion of the inner peripheral surface of the fixing component 503. When the traveling of the reflected light is suppressed, the reflected light is suppressed from being reflected at a portion of the surface of the ring component 501 and a portion of the inner peripheral surface of the fixing component 503. When the reflection of the reflected light is suppressed, the traveling of the reflected light from a portion of the surface of the ring component 501 and a portion of the inner peripheral surface of the fixing component 503 through the window 31a to a portion of the closely contacting surface of the sealing component 400a closely contacting the laser gas side surface of the window 31a is suppressed. Therefore, it is possible to suppress the reflected light from being irradiated to the sealing component 400a for a predetermined time or longer, and it is possible to suppress the sealing component 400a from being deteriorated earlier than the period assumed in advance. When the deterioration of the sealing member 400a is suppressed, the service life of the sealing member 400a is suppressed from being shorter than the pre-assumed period. Therefore, it is possible to suppress the usable period of the gas laser device 100 from being shorter than the pre-assumed period.

[0124] Furthermore, when the degradation of the sealing member 400a is suppressed, the service life of the sealing member 400a is extended compared to the case where the extension surface 315 is not formed. When the service life of the sealing member 400a is extended, the usable period of the gas laser device 100 can be extended while the internal space of the housing 30 and the space between the hollow portion 301 and the end surface 303 and the window 31a are kept sealed.

[0125] Furthermore, in the gas laser device 100 of the present embodiment, the extension surface 315 reflects the reflected light so that the reflected light enters the window 31a from the outer peripheral side of the window 31a toward the central axis C side of the window 31a across the normal line 600. Thus, compared with the case where the extension surface 315 does not reflect as described above, it is possible to suppress the sealing member 400a from being degraded earlier than the pre-assumed period.

[0126] In addition, a part of the reflected light that is reflected by the extension surface 315 and travels inside the window 31a is sometimes reflected by the purge gas side surface of the window 31a toward the laser gas side surface of the window 31a. In addition, a part of the reflected light that travels toward the laser gas side surface of the window 31a is sometimes reflected by the laser gas side surface of the window 31a toward the purge gas side surface of the window 31a. When such reflection is repeated, the intensity of the reflected light that travels inside the window 31a becomes weaker. In this embodiment, as described above, in order to return the reflected light that passes through the window 31a to a part of the surface of the ring component 501 located on the outer peripheral side and a part of the inner peripheral surface of the fixing component 503 in the reflection side area, the reflected light may be reflected more than the comparative example. Thus, by the extension surface 315 that is inclined and reflected as described above, the number of reflections at the window 31a is more than the number of reflections in the comparative example. Therefore, the intensity of the reflected light of this embodiment that travels toward the sealing component 400a is weaker than the intensity of the reflected light of the comparative example that travels toward the sealing component 400a. When the intensity of reflected light is weakened, even if the reflected light reflected by the extension surface 315 travels from the inside of the window 31a toward the sealing member 400a and irradiates the sealing member 400a, it is possible to suppress the sealing member 400a from being degraded earlier than the pre-assumed period.

[0127] The extended surface 315 may be polished for reflection. In addition, a reflective film formed by thinly plating a metal such as silver or aluminum may be disposed on the extended surface 315. The extended surface 315 may also reflect the reflected light toward the inner peripheral surface of the window holder 300a in the hollow portion 301.

[0128] Next, other embodiments and variations of the embodiment are described. In each embodiment and variation of the embodiment, the structure not particularly described is the same as that of embodiment 1. In addition, in each embodiment and variation of the embodiment, the window 31a and the window holder 300a side are used for description, but the window 31b and the window holder 300b of each embodiment and variation of the embodiment are the same structures as the window 31a and the window holder 300a of each embodiment and variation of the embodiment, and the same action / effect can be obtained.

[0129] 4. Description of the Gas Laser Device of Embodiment 2

[0130] Next, the configuration of the gas laser device 100 according to Embodiment 2 will be described. The same reference numerals are used for the same configurations as those described above, and the duplicate description will be omitted unless otherwise specified.

[0131] 4.1 Structure

[0132] Figure 731a and the window holder 300a in the present embodiment. Figure 7 In FIG. 1 , the window 31a and the window holder 300a are shown using a vertical cross section.

[0133] The structure of the window 31a is different from that of the window 31a of Embodiment 1, and the other structures are the same as those of Embodiment 1. The gas laser device 100 of this embodiment further includes films 321a and 321b in the structure of the gas laser device 100 of Embodiment 1. The films 321a and 321b are included in the structure of the window 31a.

[0134] The film 321a is a first film disposed on the abutting surface of the laser gas side surface of the window 31a that abuts against the sealing component 400a. The film 321a is disposed on the reflection direction side of the reflected light reflected by the window 31a in the abutting surface, and is disposed on a portion of the laser gas side surface of the window 31a located in the reflection side area. The film 321a abuts against a portion of the sealing component 400a located in the reflection side area. The film 321a is mainly composed of aluminum and is a reflective film that reflects at least a portion of the light of the same wavelength as the reflected light shown by the arrow F13 toward the purge gas side surface of the window 31a and the outer peripheral surface of the window 31a. The film 321a is disposed, for example, by vapor deposition. The thickness of the film 321a is preferably about 200nm.

[0135] The film 321b is a second film disposed on the abutting surface of the purge gas side surface of the window 31a that abuts against the ring member 501. The film 321b is disposed on the reflection direction side of the reflected light reflected by the window 31a in the abutting surface, and is disposed on a portion of the purge gas side surface of the window 31a located in the reflection side region. The film 321b abuts against a portion of the ring member 501 located in the reflection side region. The film 321b is mainly composed of aluminum oxide and is an absorption film that absorbs at least a portion of light of the same wavelength as the reflected light shown by the arrow F13. The film 321b is disposed, for example, by vapor deposition. The thickness of the film 321b is preferably about 200nm.

[0136] 4.2 Effects

[0137] As described above, of the reflected light reflected by the extension surface 315 and traveling inside the window 31a, a portion of the reflected light is sometimes reflected by the laser gas side surface of the window 31a toward the purge gas side surface of the window 31a. In addition, a portion of the reflected light traveling toward the purge gas side surface of the window 31a is sometimes reflected by the purge gas side surface of the window 31a toward the laser gas side surface of the window 31a. This light is light of the same wavelength as the reflected light indicated by the arrow F13, and at least a portion of the light is repeatedly reflected inside the window 31a.

[0138] The film 321a on the laser gas side surface of the window 31a is a reflective film, and therefore, the light traveling toward the film 321a among the reflected light that repeatedly undergoes the above-mentioned reflection is reflected toward the outer peripheral surface of the window 31a, the film 321b on the purge gas side surface of the window 31a, and a portion of the purge gas side surface of the window 31a. The portion of the purge gas side surface is an area of ​​the purge gas side surface where the ring member 501 is not arranged.

[0139] Furthermore, the film 321b on the purge gas side surface of the window 31a absorbs, among the reflected light repeatedly reflected as described above, light from the laser gas side surface of the window 31a or light from the film 321a as a reflective film.

[0140] Therefore, in the gas laser device 100 of the present embodiment, the film 321a further suppresses the reflected light from being irradiated toward the sealing member 400a, and further suppresses the sealing member 400a from deteriorating earlier than the pre-assumed period. When the degradation of the sealing member 400a is suppressed, the situation that the service life of the sealing member 400a is shorter than the pre-assumed period is suppressed. Therefore, it is possible to suppress the usable period of the gas laser device 100 from being shorter than the pre-assumed period. In addition, the film 321b also obtains the same action / effect as the film 321a.

[0141] As a modification 1 of the present embodiment, one of the film 321a on the laser gas side surface of the window 31a and the film 321b on the purge gas side surface of the window 31a may be a reflective film, and the other may be an absorption film. For example, when the film 321a on the laser gas side surface of the window 31a is an absorption film, the absorption film absorbs at least a portion of the light traveling from the window 31a to the sealing member 400a. For example, when the film 321b on the purge gas side surface of the window 31a is a reflective film, the reflective film reflects at least a portion of the light toward the surface on the side where the sealing member 400a is arranged, that is, the laser gas side surface of the window 31a and the outer peripheral surface of the window 31a. The above light is light of the same wavelength as the reflected light indicated by the arrow F13.

[0142] As a second modification of the present embodiment, both the film 321 a on the laser gas side surface of the window 31 a and the film 321 b on the purge gas side surface of the window 31 a may be a reflective film or an absorption film.

[0143] As a third variation of the present embodiment, the film 321a on the laser gas side surface of the window 31a may be arranged on the entire surface of the laser gas side surface of the window 31a that contacts the sealing member 400a. Therefore, the film 321a is arranged in an annular shape, similar to the annular sealing member 400a.

[0144] As a fourth modification of the present embodiment, the film 321b on the purge gas side surface of the window 31a may be disposed on the entire surface of the purge gas side surface of the window 31a that contacts the ring member 501. Therefore, like the ring member 501, the film 321b is disposed in an annular shape.

[0145] As a variation 5 of this embodiment, Figure 8 As shown, the film 321a may be disposed only on the laser gas side surface of the window 31a instead of the film 321b on the purge gas side surface of the window 31a. In this case, the film 321a may be a reflective film or an absorption film.

[0146] As a variation 6 of this embodiment, Fig. 9 As shown, film 321a may not be disposed on the laser gas side surface of window 31a, but film 321b may be disposed only on the purge gas side surface of window 31a. In this case, film 321b is an absorption film.

[0147] As a seventh modification of the present embodiment, the reflective film may be a dielectric multilayer film. Furthermore, the absorbing film may be a film colored in black.

[0148] In the second embodiment and the modified example, the film is used for description, but it is not necessary to be limited to this. For example, a plate-shaped reflective member may be arranged instead of a reflective film, and a plate-shaped absorbing member may be arranged instead of an absorbing film.

[0149] 5. Description of the gas laser device according to Embodiment 3

[0150] Next, the configuration of the gas laser device 100 according to Embodiment 3 will be described. The same reference numerals are used for the same configurations as those described above, and the duplicate description will be omitted unless otherwise specified.

[0151] 5.1 Structure

[0152] Fig.10 31a and the window holder 300a in the present embodiment. Fig.10 In FIG. 1 , the window 31a and the window holder 300a are shown using a vertical cross section.

[0153] In the gas laser device 100 of the present embodiment, the structure of the window holder 300 a is different from that of the window holder 300 a of the first embodiment, and the window holder 300 a of the present embodiment absorbs reflected light.

[0154] Specifically, in this embodiment, the extension surface 315 is subjected to black plating and is an absorption surface that absorbs reflected light traveling from the window 31a to the extension surface 315. Most of the reflected light is converted into heat by the extension surface 315. The heat is released from the window holder 300a to the outside.

[0155] 5.2 Effects

[0156] In the gas laser device 100 of this embodiment, the extension surface 315 absorbs the reflected light from the window 31a. Therefore, the reflected light is suppressed from traveling from the extension surface 315 toward the window 31a, and the irradiation of the light traveling from the window 31a to the sealing member 400a is further suppressed, and the sealing member 400a is further suppressed from deteriorating earlier than the pre-assumed period. When the degradation of the sealing member 400a is suppressed, the situation that the service life of the sealing member 400a is shorter than the pre-assumed period is suppressed. Therefore, the usable period of the gas laser device 100 can be suppressed from being shorter than the pre-assumed period.

[0157] Furthermore, since the window holder 300 a has the extended surface 315 as the absorbing surface, the number of components can be reduced compared to a case where another component having an absorbing surface is arranged on the extended surface 315 .

[0158] 6. Description of the Gas Laser Device of Embodiment 4

[0159] Next, the structure of the gas laser device 100 according to Embodiment 4 will be described. The same reference numerals are used for the same structures as those described above, and the duplicate description will be omitted unless otherwise specified.

[0160] 6.1 Structure

[0161] Fig.11 31a and the window holder 300a in the present embodiment. Fig.11 In FIG. 1 , the window 31a and the window holder 300a are shown using a vertical cross section.

[0162] In the gas laser device 100 of this embodiment, the structure of the window holder 300 a is different from the structure of the window holder 300 a of the third embodiment. The window holder 300 a further includes an absorbing member 331 in the structure of the window holder 300 a of the third embodiment.

[0163] The absorbing member 331 is plate-shaped and is disposed on the extension surface 315. The absorbing member 331 is disposed so as to be stacked integrally with the extension surface 315. The absorbing member 331 is disposed inside the recessed portion 310. The absorbing member 331 is mainly composed of aluminum oxide, and absorbs the reflected light traveling from the window 31a to the absorbing member 331. The thickness of the absorbing member 331 is preferably about 0.3 mm. The absorbing member 331 may also be composed of a member colored black.

[0164] 6.2 Action / Effect

[0165] In the gas laser device 100 of this embodiment, the absorption member 331 absorbs the reflected light from the window 31a. Therefore, the reflected light is suppressed from traveling from the absorption member 331 toward the window 31a, and the irradiation of the light traveling from the window 31a to the sealing member 400a is further suppressed, and the sealing member 400a is further suppressed from deteriorating earlier than the pre-assumed period. When the degradation of the sealing member 400a is suppressed, the situation that the service life of the sealing member 400a is shorter than the pre-assumed period is suppressed. Therefore, the usable period of the gas laser device 100 can be suppressed from being shorter than the pre-assumed period.

[0166] Furthermore, since the absorbing member 331 is separate from the window holder 300a, it is possible to reduce the labor and time required to perform black plating on the window holder 300a.

[0167] The absorbing member 331 may be disposed at the irradiation position of the reflected light in the extension surface 315. If the light from the window 31a travels toward the side surface 313, the absorbing member 331 may also be disposed on the side surface 313.

[0168] In the gas laser device 100 of the present embodiment, the window holder 300 a including the side surface 313 and the extended surface 315 may be configured as the absorbing member 331 .

[0169] 7. Description of the gas laser device according to the fifth embodiment

[0170] Next, the structure of the gas laser device 100 according to Embodiment 5 will be described. The same reference numerals are used for the same structures as those described above, and the overlapping description will be omitted unless otherwise specified.

[0171] 7.1 Structure

[0172] Fig.12 31a and the window holder 300a in the present embodiment. Fig.12 In FIG. 3 , the window 31a and the window holder 300a are represented by a vertical cross section. Fig.13 In the enlarged view, Fig.12FIG. 6 is a schematic diagram of an area surrounded by a solid circle 604 .

[0173] In the gas laser device 100 of the present embodiment, the structure of the recessed portion 310 is different from the structure of the recessed portion 310 of the fourth embodiment.

[0174] Unlike the recessed portion 310 of the fourth embodiment, the recessed portion 310 is not recessed from the end surface 303 toward the hollow portion 301 , is not communicated with the hollow portion 301 , and is recessed in a portion of the end surface 303 .

[0175] The extension surface 315 of this embodiment is a side surface of the recessed portion 310. The extension surface 315 is arranged so as to surround the central axis of the bottom surface 317 over the entire circumference. The extension surface 315 is arranged not parallel to the laser gas side surface of the window 31a.

[0176] The bottom surface 317 is continuous with the extension surface 315 . The bottom surface 317 is disposed so as to face the window 31 a . The end surface 303 is disposed in parallel with the laser gas side surface of the window 31 a . An absorbing member 331 is disposed on the bottom surface 317 .

[0177] The area of ​​the extension surface 315 and the bottom surface 317 where the absorbing member 331 is not arranged is processed to have a surface roughness of about Ra1.6. The extension surface 315 reflects a part of the reflected light from the window 31a toward the absorbing member 331, and reflects another part of the reflected light toward other areas of the extension surface 315. In addition, the extension surface 315 reflects the rest of the reflected light toward the bottom surface 317. The bottom surface 317 reflects a part of the reflected light from the extension surface 315 toward the absorbing member 331, and reflects the rest of the reflected light from the extension surface 315 toward the extension surface 315.

[0178] The absorbing member 331 of the present embodiment is conical in shape and is disposed on a portion of the bottom surface 317. The end of the absorbing member 331 is located closer to the bottom surface 317 than the opening 311, and is located inside the recessed portion 310. The absorbing member 331 is mainly composed of, for example, aluminum oxide. The absorbing member 331 may also be composed of a member colored in black. The absorbing member 331 absorbs reflected light that travels from the window 31a to the absorbing member 331 via the extension surface 315. In addition, the absorbing member 331 absorbs reflected light that travels from the extension surface 315 to the absorbing member 331 via other extension surfaces 315. Furthermore, the absorbing member 331 absorbs reflected light that travels from the extension surface 315 to the absorbing member 331 via the bottom surface 317.

[0179] 7.2 Action / Effect

[0180] As indicated by the solid arrow F12, the reflected light from the window 31a travels from the laser gas side surface of the window 31a toward the recessed portion 310. Furthermore, as indicated by the solid arrow F12, the reflected light travels from the opening 311 of the recessed portion 310 toward the inside of the recessed portion 310 and directly travels toward the extension surface 315 of the recessed portion 310. As indicated by the solid arrow F14, a portion of the reflected light is reflected toward the absorbing member 331 by the extension surface 315. As indicated by the solid arrow F15, another portion of the reflected light is reflected toward the bottom surface 317 by the extension surface 315, and further reflected toward the absorbing member 331 by the bottom surface 317. Another portion of the reflected light is reflected toward the other extension surface 315 by the extension surface 315, and further reflected toward the absorbing member 331 by the other extension surface 315, as indicated by the solid arrow F16. The remaining portion of the reflected light is reflected toward the extension surface 315 by the bottom surface 317, and further reflected toward the absorbing member 331 by the extension surface 315. Thus, the reflected light is repeatedly reflected between the extension surface 315 and the bottom surface 317 , and is suppressed from traveling from the inner space of the recessed portion 310 to the outer space of the recessed portion 310 where the window 31 a is arranged, and is absorbed by the absorbing member 331 .

[0181] In the gas laser device 100 of this embodiment, the absorption member 331 absorbs the reflected light that travels from the window 31a to the absorption member 331 via the extension surface 315. In addition, the absorption member 331 also absorbs the reflected light that travels from the extension surface 315 to the absorption member 331 via the bottom surface 317. Therefore, the reflected light is suppressed from traveling from the absorption member 331 to the window 31a, and the irradiation of the light that travels from the window 31a to the sealing member 400a is further suppressed, and the sealing member 400a is further suppressed from deteriorating earlier than the pre-assumed period. When the degradation of the sealing member 400a is suppressed, the situation that the service life period of the sealing member 400a is shorter than the pre-assumed period is suppressed. Therefore, the usable period of the gas laser device 100 can be suppressed from being shorter than the pre-assumed period.

[0182] Alternatively, the extended surface 315 to which the reflected light from the window 31a directly travels may reflect all of the reflected light directly toward the sealing member 400a, without reflecting the reflected light toward other extended surfaces 315 and the bottom surface 317 to which the reflected light from the window 31a does not directly travel. In addition, similar to the recessed portion 310 of Embodiment 4, the recessed portion 310 may be recessed from the end surface 303 toward the hollow portion 301 and communicate with the hollow portion 301. The reflected light reflected by the extended surface 315 can travel toward the inner peripheral surface of the window holder 300a in the hollow portion 301, be reflected by the inner peripheral surface, and return to the internal space of the housing 30.

[0183] A coating or surface treatment for improving light absorption rate may be applied to the extension surface 315 and the bottom surface 317. For example, an absorption film mainly composed of aluminum oxide may be disposed on the extension surface 315 and the bottom surface 317.

[0184] The above description is not limiting but simply illustrative. Therefore, it is clear to those skilled in the art that changes can be made to the embodiments of the present disclosure without departing from the claims. In addition, it is also clear to those skilled in the art that the embodiments of the present disclosure can be used in combination.

[0185] Unless explicitly stated otherwise, the terms used in this specification and claims as a whole should be interpreted as "non-limiting" terms. For example, terms such as "including" or "comprising" should be interpreted as "not limited to the parts recorded as included". Terms such as "having" should be interpreted as "not limited to the parts recorded as having". In addition, the indefinite article "one" should be interpreted as meaning "at least one" or "one or more". In addition, terms such as "at least one of A, B and C" should be interpreted as "A", "B", "C", "A+B", "A+C", "B+C" or "A+B+C". Furthermore, it should be interpreted as also including combinations of them and parts other than "A", "B", and "C".

Claims

1. A gas laser device, comprising: a housing including an inner space for generating light by excitation of laser gas and a hole for emitting the light from the inner space; a cylindrical window holder, which is arranged on the housing and includes a hollow portion through which the light emitted from the hole passes; a window that transmits the light traveling in the hollow portion, and is held by the window holder in a state where a surface for incident light is inclined with respect to an optical axis of the light traveling in the hollow portion; and an annular sealing member configured to surround an opening through which the light passing through the hollow portion passes, and to seal between the window and the window holder at a surface of the window in contact with the laser gas, The window holder further includes a recessed portion having an extended surface as a bottom surface, the extended surface being irradiated with reflected light reflected by the window among the light traveling toward the window through the opening, The recessed portion is recessed from the end surface of the window holder that is opposite to the window and communicates with the hollow portion. The extension surface includes one end continuous with the end surface and the other end continuous with the inner circumferential surface of the hollow portion, and is formed between the end surface and the inner circumferential surface of the hollow portion, and the extension surface is inclined relative to the optical axis of the light traveling in the hollow portion in such a manner that the one end is located farther from the optical axis of the light traveling in the hollow portion than the other end.

2. The gas laser device according to claim 1, wherein: The extended surface reflects the reflected light.

3. The gas laser device according to claim 2, wherein: The window further includes a film, the film being disposed on a surface of the window that contacts the sealing member and reflecting at least a portion of light having the same wavelength as the reflected light.

4. The gas laser device according to claim 3, wherein: The gas laser device further includes a ring member, which is arranged on the window at a side opposite to the sealing member with respect to the window. The window includes a film, the film being disposed on a surface of the window that contacts the ring member and absorbing at least a portion of light having the same wavelength as the reflected light.

5. The gas laser device according to claim 3, wherein: The gas laser device further includes a ring member, which is arranged on the window at a side opposite to the sealing member with respect to the window. The window includes a film, the film being disposed on a surface of the window that contacts the ring member and reflecting at least a portion of light having the same wavelength as the reflected light.

6. The gas laser device according to claim 2, wherein: The window further includes a film, the film being disposed on a surface of the window that contacts the sealing member and absorbing at least a portion of light having the same wavelength as the reflected light.

7. The gas laser device according to claim 6, wherein: The gas laser device further includes a ring member, which is arranged on the window at a side opposite to the sealing member with respect to the window. The window includes a film, the film being disposed on a surface of the window that contacts the ring member and absorbing at least a portion of light having the same wavelength as the reflected light.

8. The gas laser device according to claim 6, wherein: The gas laser device includes a ring member, and the ring member is arranged on the window at a side opposite to the sealing member with respect to the window. The window includes a film, the film being disposed on a surface of the window that contacts the ring member and reflecting at least a portion of light having the same wavelength as the reflected light.

9. The gas laser device according to claim 2, wherein: The gas laser device further includes a ring member, which is arranged on the window at a side opposite to the sealing member with respect to the window. The window includes a film, the film being disposed on a surface of the window that contacts the ring member and absorbing light having the same wavelength as the reflected light.

10. The gas laser device according to claim 1, wherein: The window holder absorbs the reflected light.

11. The gas laser device according to claim 10, wherein: The extended surface absorbs the reflected light.

12. The gas laser device according to claim 11, wherein: The extension surface is an absorption surface that has been subjected to a black plating treatment.

13. The gas laser device according to claim 1, wherein: The window holder further includes an absorbing component disposed on the extension surface. The absorption member absorbs the reflected light.

14. A method for manufacturing an electronic device, comprising the following steps: The laser light emitted from the gas laser device is incident on the exposure device. exposing the laser on a photosensitive substrate in the exposure device to manufacture an electronic device, The gas laser device comprises: a housing including an inner space for generating light by excitation of laser gas and a hole for emitting the light from the inner space; a cylindrical window holder, which is arranged on the housing and includes a hollow portion through which the light emitted from the hole passes; a window that transmits the light traveling in the hollow portion, and is held by the window holder in a state where a surface for incident light is inclined with respect to an optical axis of the light traveling in the hollow portion; as well as an annular sealing member configured to surround an opening through which the light passing through the hollow portion passes, and to seal between the window and the window holder at a surface of the window in contact with the laser gas, The window holder further includes a recessed portion having an extended surface as a bottom surface, the extended surface being irradiated with reflected light reflected by the window among the light traveling toward the window through the opening, The recessed portion is recessed from the end surface of the window holder that is opposite to the window and communicates with the hollow portion. The extension surface includes one end continuous with the end surface and the other end continuous with the inner circumferential surface of the hollow portion, and is formed between the end surface and the inner circumferential surface of the hollow portion. The extension surface is inclined relative to the optical axis of the light traveling in the hollow portion in such a manner that the one end is located farther from the optical axis of the light traveling in the hollow portion than the other end.

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