Chamber device for gas laser device, gas laser device, and method for manufacturing electronic device

Abstract

To provide a chamber device for a gas laser device capable of outputting laser light with stable pulse energy even at a high repetition frequency.SOLUTION: A chamber device of a gas laser device includes: a chamber body; an anode extending along a Z direction; a cathode extending along the Z direction and including a base portion 401 and a discharge portion 403 protruding from the base portion; a cathode side sound absorbing portion 470 including a base facing portion 453 spaced apart from the base portion in a V direction and overlapped partially and spaced apart from the discharge portion in an H direction and overlapped partially, and arranged in a space between a cathode side cover portion 450 covering the base portion and the base portion; and an inclined portion 480a arranged in a space on the base portion side than the base facing portion in the V direction and on the discharge portion side than the base facing portion in the H direction, expanding in a direction away from the discharge portion when progressing in a direction from the discharge portion side toward the base portion side along the V direction, and having an inclined surface extending in the Z direction.SELECTED DRAWING: Figure 6

Description

[Technical Field]

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

[0002] In recent years, semiconductor exposure equipment has been required to improve its resolution in response to the miniaturization and high integration of semiconductor integrated circuits. To this end, the wavelength of light emitted from exposure light sources has been shortened. For example, gas laser devices used for exposure include KrF excimer laser devices that output laser light with a wavelength of approximately 248 nm and ArF excimer laser devices that output laser light with a wavelength of approximately 193 nm.

[0003] The spectral linewidth of the spontaneously oscillating light from KrF excimer laser devices and ArF excimer laser devices is as wide as 350 to 400 pm. Therefore, if a projection lens is constructed using a material that transmits ultraviolet light, such as KrF and ArF laser light, chromatic aberration may occur. As a result, resolution may decrease. Therefore, it is necessary to narrow the spectral linewidth of the laser light output from the gas laser device to a level where chromatic aberration is negligible. Therefore, a line narrowing module (LNM) containing a line narrowing element (e.g., an etalon or grating) may be installed inside the laser resonator of the gas laser device to narrow the spectral linewidth. Hereinafter, a gas laser device with a narrowed spectral linewidth is referred to as a line narrowing gas laser device. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent No. 6,810,061 [Patent Document 2] U.S. Patent No. 6,639,929 [Patent Document 3] Japanese Patent Application Publication No. 6-85350 [Patent Document 4] Patent No. 4579002 [Patent Document 5] Patent No. 4918699 Publication Overview

[0005] a cathode-side cover portion including a base opposing portion spaced apart from the base portion in the first direction and overlapping with a portion of the base portion in the second direction, and spaced apart from the discharge portion and overlapping with the discharge portion in the second direction, the cathode-side cover portion covering a portion of the base portion; a cathode-side sound-absorbing member disposed in the space between the cathode-side cover portion and the base portion; and an inclined portion having an inclined surface extending in the predetermined direction, at least a portion of which is located in the space closer to the base portion than the base opposing portion in the first direction and closer to the discharge portion than the base opposing portion in the second direction, the inclined portion having an inclined surface extending in the predetermined direction and expanding in a direction away from the discharge portion when extending in a direction from the discharge portion side toward the base portion side.

[0006] A gas laser device according to one aspect of the present disclosure is a gas laser device including a chamber device that emits laser light, the chamber device including a chamber body, an anode that is disposed in an internal space of the chamber body and has a longitudinal direction extending along a predetermined direction, and a cathode that is disposed in the internal space facing the anode in a first direction away from the anode and has a longitudinal direction extending along the predetermined direction, the cathode including a base portion and a discharge portion that has a width in a second direction perpendicular to the predetermined direction and the first direction that is smaller than that of the base portion and that protrudes from the base portion toward the anode; a cathode-side cover part that covers the base part and includes a base opposing part that is separated from the discharge part in the first direction and overlaps with a part of the base part, and that is separated from the discharge part in the second direction and overlaps with the discharge part, a cathode-side sound-absorbing member that is arranged in the space between the cathode-side cover part and the base part, and an inclined part that is at least partially arranged in the space that is closer to the base part than the base opposing part in the first direction and closer to the discharge part than the base opposing part in the second direction, and that has an inclined surface that expands in a direction away from the discharge part when progressing in a direction from the discharge part side to the base part side and extends in a predetermined direction.

[0007] A method for manufacturing an electronic device according to one aspect of the present disclosure includes a chamber body, an anode disposed in an internal space of the chamber body and having a longitudinal direction extending along a predetermined direction, a cathode disposed in the internal space in a first direction facing and away from the anode and having a longitudinal direction extending along the predetermined direction, the cathode including a base portion and a discharge portion having a width in a second direction perpendicular to the predetermined direction and the first direction that is smaller than that of the base portion and protruding from the base portion toward the anode, and a base opposing portion spaced apart from the base portion in the first direction and overlapping with a part of the base portion and spaced apart from the discharge portion in the second direction and overlapping with the discharge portion, the cathode-side cover portion covering the discharge portion and the base portion, the cathode-side sound-absorbing member arranged in the space between the cathode-side cover portion and the base portion, and an inclined portion having an inclined surface extending in a predetermined direction and expanding in a direction away from the discharge portion when proceeding in a direction from the discharge portion side to the base portion side, and at least a portion of which is arranged in the space that is closer to the base portion than the base facing portion in a first direction and closer to the discharge portion than the base facing portion in a second direction, the inclined portion having an inclined surface extending in a predetermined direction, the inclined portion expanding in a direction away from the discharge portion when proceeding in a direction from the discharge portion side to the base portion side, the inclined portion [Brief explanation of the drawings]

[0008] Some embodiments of the present disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which: [Figure 1] FIG. 1 is a schematic diagram showing an example of the overall configuration of an electronic device manufacturing apparatus. [Figure 2] FIG. 2 is a schematic diagram showing an example of the overall configuration of a gas laser device of a comparative example. [Figure 3] FIG. 3 is a cross-sectional view of a chamber apparatus of a comparative example taken along a plane perpendicular to the optical axis of the laser light. [Figure 4] FIG. 4 is a cross-sectional view of the periphery of the cathode and anode shown in FIG. 3, taken along a plane perpendicular to the optical axis of the laser light. [Figure 5] FIG. 5 is a cross-sectional view of the periphery of the cathode shown in FIG. 3, taken along a plane perpendicular to the optical axis of the laser light. [Figure 6]FIG. 6 is a cross-sectional view of the periphery of the cathode in the first embodiment, taken along a line perpendicular to the optical axis of the laser light. [Figure 7] FIG. 7 is a cross-sectional view of the periphery of the cathode in the first embodiment, taken along a line perpendicular to the optical axis of the laser light. [Figure 8] FIG. 8 is a cross-sectional view of the periphery of the cathode in the first embodiment, taken along a line perpendicular to the optical axis of the laser light. [Figure 9] FIG. 9 is a cross-sectional view of the periphery of the cathode, taken along a plane perpendicular to the optical axis of the laser light. [Figure 10] FIG. 10 is a perspective view of an inclined portion in a first modified example of the first embodiment. [Figure 11] FIG. 11 is a cross-sectional view of the periphery of the cathode in a second modified example of the first embodiment, taken along a line perpendicular to the optical axis of the laser light. [Figure 12] FIG. 12 is a cross-sectional view of the periphery of the cathode in a third modified example of the first embodiment, taken along a line perpendicular to the optical axis of the laser light. [Figure 13] FIG. 13 is a cross-sectional view of the periphery of the cathode in a fourth modification of the first embodiment, taken along a line perpendicular to the optical axis of the laser light. [Figure 14] FIG. 14 is a cross-sectional view of the periphery of the cathode in the second embodiment, taken along a line perpendicular to the optical axis of the laser light. [Figure 15] FIG. 15 is a cross-sectional view of the periphery of the cathode in the third embodiment, taken along a line perpendicular to the optical axis of the laser light. [Figure 16] FIG. 16 is a cross-sectional view taken along the line AA shown in FIG. [Figure 17] FIG. 17 is a cross-sectional view taken along line BB in FIG. [Figure 18] FIG. 18 is a cross-sectional view taken along line CC in FIG. [Figure 19] FIG. 19 is a cross-sectional view taken along line DD in FIG. [Figure 20] FIG. 20 is a cross-sectional view of the periphery of the cathode in the fourth embodiment, taken along a line perpendicular to the optical axis of the laser light. [Figure 21] FIG. 21 is a cross-sectional view of the periphery of the cathode taken along a plane perpendicular to the optical axis of the laser light. [Figure 22]FIG. 22 is a cross-sectional view of the periphery of the cathode in the sixth embodiment, taken along a line perpendicular to the optical axis of the laser light. [Figure 23] FIG. 23 is a cross-sectional view of the periphery of the anode in the seventh embodiment, taken along a line perpendicular to the optical axis of the laser light. Embodiment

[0009] 1. Explanation of the electronic device manufacturing equipment used in the exposure process of electronic devices 2. Explanation of comparative examples 2.1 Configuration 2.2 Operation 3. Challenges 4. Description of Embodiment 1 4.1 Configuration 4.2 Actions and Effects 4.3 First Modification of the First Embodiment 4.3.1 Configuration 4.3.2 Actions and Effects 4.4 Second Modification of the First Embodiment 4.4.1 Configuration 4.4.2 Actions and Effects 4.5 Third Modification of the First Embodiment 4.5.1 Configuration 4.5.2 Actions and Effects 4.6 Fourth Modification of the First Embodiment 4.6.1 Configuration 4.6.2 Actions and Effects 5. Description of Embodiment 2 5.1 Configuration 5.2 Actions and Effects 6. Description of Embodiment 3 6.1 Configuration 6.2 Actions and Effects 7. Description of Embodiment 4 7.1 Configuration 7.2 Actions and Effects 8. Description of Embodiment 5 8.1 Configuration 8.2 Actions and Effects 9. Description of Embodiment 6 9.1 Configuration 9.2 Actions and Effects 10. Description of Embodiment 7 10.1 Configuration 10.2 Actions and Effects

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The embodiments described below show some examples of the present disclosure and do not limit the content of the present disclosure. Furthermore, not all of the configurations and operations described in each embodiment are necessarily essential as the configurations and operations of the present disclosure. Note that the same components are given the same reference symbols, and redundant explanations will be omitted.

[0011] 1. Explanation of the electronic device manufacturing equipment used in the exposure process of electronic devices FIG. 1 is a schematic diagram showing an example of the overall configuration of an electronic device manufacturing apparatus used in an exposure process for electronic devices. As shown in FIG. 1, the manufacturing apparatus used in the exposure process includes a gas laser apparatus 100 and an exposure apparatus 200. The exposure apparatus 200 includes an illumination optical system 210, which includes multiple mirrors 211, 212, and 213, and a projection optical system 220. The illumination optical system 210 illuminates a reticle pattern on a reticle stage RT with laser light incident from the gas laser apparatus 100. The projection optical system 220 reduces and projects the laser light transmitted through the reticle onto a workpiece (not shown) placed on a workpiece table WT. The workpiece is a photosensitive substrate such as a semiconductor wafer coated with photoresist. The exposure apparatus 200 synchronously translates the reticle stage RT and the workpiece table WT to expose the workpiece with laser light reflecting the reticle pattern. Semiconductor devices, which are electronic devices, can be manufactured by transferring a device pattern onto a semiconductor wafer using the exposure process described above.

[0012] 2. Explanation of comparative examples 2.1 Configuration A comparative example of a gas laser device 100 will be described. Note that the comparative example of the present disclosure is a configuration that the applicant recognizes as being known only by the applicant, and is not a publicly known example that the applicant acknowledges.

[0013] FIG. 2 is a schematic diagram showing an example of the overall configuration of a gas laser apparatus 100 of a comparative example. The gas laser apparatus 100 is, for example, an ArF excimer laser apparatus that uses a mixed gas containing argon (Ar), fluorine (F), and neon (Ne). This gas laser apparatus 100 outputs laser light with a center wavelength of approximately 193 nm. Note that the gas laser apparatus 100 may be a gas laser apparatus other than an ArF excimer laser apparatus, such as a KrF excimer laser apparatus that uses a mixed gas containing krypton (Kr), F, and Ne. In this case, the gas laser apparatus 100 emits laser light with a center wavelength of approximately 248 nm. A mixed gas containing Ar, F, and Ne as a laser medium, or a mixed gas containing Kr, F, and Ne as a laser medium, is sometimes called a laser gas.

[0014] Gas laser device 100 mainly includes a housing 110, a laser oscillator 130 arranged in the internal space of housing 110, a monitor module 160, a shutter 170, and a laser processor 190.

[0015] The laser oscillator 130 includes a chamber device CH, a charger 141, and an output coupling mirror 147. Fig. 2 shows the internal configuration of the chamber body 131 as viewed from a direction substantially perpendicular to the traveling direction of the laser light. Fig. 3 is a cross-sectional view perpendicular to the optical axis of the laser light of the chamber body 131 of a comparative example.

[0016] The chamber apparatus CH includes a chamber body 131, a cathode 400, an anode 500, a cathode-side cover 450, and a cathode-side sound-absorbing member 470 (described below). The chamber body 131 may be made of a metal, such as nickel-plated aluminum or nickel-plated stainless steel. The chamber body 131 contains the laser gas and includes an internal space where light is generated by excitation of the laser medium in the laser gas. The light travels to windows 139a and 139b (described below). The laser gas is supplied to the internal space of the chamber body 131 from a laser gas supply source (not shown) through piping (not shown). The laser gas in the chamber body 131 is subjected to a halogen filter to remove F2 gas, and is then exhausted to the outside of the housing 110 through piping (not shown) by an exhaust pump (not shown).

[0017] In the internal space of the chamber body 131, a cathode 400 serving as a first main electrode and an anode 500 serving as a second main electrode are spaced apart and face each other, with their respective longitudinal directions aligned along a predetermined direction that is the direction in which the laser light travels. Hereinafter, the longitudinal direction of the cathode 400 and the anode 500 will be referred to as the Z direction, and the direction in which the cathode 400 and the anode 500 are spaced apart and perpendicular to the Z direction will be referred to as the V direction or first direction. The direction perpendicular to the V direction and the Z direction will be referred to as the H direction or second direction. The cathode 400 and the anode 500 are discharge electrodes for exciting a laser medium by glow discharge.

[0018] The cathode 400 is fixed to the surface of the plate-shaped electrical insulator 135 facing the internal space of the chamber body 131 by a conductive member 157, for example, made of a bolt. The conductive member 157 is electrically connected to the pulse power module 143 and applies a high voltage from the pulse power module 143 to the cathode 400. The anode 500 is supported by and electrically connected to the ground plate 137.

[0019] The electrical insulator 135 includes an insulator. Examples of materials for the electrical insulator 135 include alumina ceramics, which have low reactivity with F2 gas. The electrical insulator 135 only needs to have electrical insulation properties, and examples of materials for the electrical insulator 135 include resins such as phenolic resins and fluororesins, as well as quartz and glass. The electrical insulator 135 closes an opening provided in the chamber body 131 and is fixed to the chamber body 131.

[0020] Charger 141 is a DC power supply device that charges a charging capacitor (not shown) in pulse power module 143 with a predetermined voltage. Pulse power module 143 includes switch 143a controlled by laser processor 190. When switch 143a is turned from OFF to ON, pulse power module 143 generates a pulsed high voltage from the electrical energy stored in the charging capacitor and applies this high voltage to cathode 400.

[0021] When a high voltage is applied to the cathode 400, a discharge occurs between the cathode 400 and the anode 500. The energy of this discharge excites the laser medium in the discharge space between the cathode 400 and the anode 500 (hereinafter simply referred to as the discharge space), and the excited laser medium emits light when it transitions to the ground state.

[0022] A pair of windows 139a and 139b are provided on the wall surface of the chamber body 131. Window 139a is located on one side of the chamber body 131 in the traveling direction of the laser light, and window 139b is located on the other side in the traveling direction, with the windows 139a and 139b sandwiching a discharge space. The windows 139a and 139b are inclined at a Brewster angle with respect to the traveling direction of the laser light so as to suppress reflection of P-polarized laser light. As described below, the oscillated laser light is emitted to the outside of the chamber body 131 via the windows 139a and 139b. Since a pulsed high voltage is applied between the cathode 400 and the anode 500 by the pulse power module 143 as described above, this laser light is pulsed laser light.

[0023] A cross-flow fan 149 and a heat exchanger 151 are further disposed in the internal space of the chamber body 131 .

[0024] The crossflow fan 149 and heat exchanger 151 are disposed on the opposite side of the anode 500 with respect to the ground plate 137. In the internal space of the chamber body 131, the space in which the crossflow fan 149 and heat exchanger 151 are disposed is connected to the discharge space. The heat exchanger 151 is a radiator disposed beside the crossflow fan 149 and connected to a pipe (not shown) through which a liquid or gas cooling medium flows. As shown in FIG. 2, the crossflow fan 149 is connected to a motor 149a disposed outside the chamber body 131 and rotates with the rotation of the motor 149a. As the crossflow fan 149 rotates, the laser gas sealed in the internal space of the chamber body 131 circulates as shown by the thick arrows in FIG. 3. In other words, the laser gas circulates in the order of the crossflow fan 149, the discharge space, the heat exchanger 151, and the crossflow fan 149. Therefore, at least a portion of the circulating laser gas passes through heat exchanger 151, which adjusts the temperature of the laser gas. As the laser gas circulates, impurities in the laser gas generated by the main discharge between cathode 400 and anode 500 move downstream, and fresh laser gas is supplied to the discharge space at the time of the next discharge. In addition, as the laser gas passes through heat exchanger 151, heat associated with the main discharge is removed, suppressing a rise in the temperature of the laser gas. The ON / OFF and rotation speed of motor 149a are adjusted by control of laser processor 190. Therefore, by controlling motor 149a, laser processor 190 can adjust the circulation speed of the laser gas circulating within the internal space of chamber body 131.

[0025] The direction of the flow of the laser gas between the cathode 400 and the anode 500 is the +H direction side, and the −H direction side may be described as the upstream side, and the +H direction side as the downstream side.

[0026] The ground plate 137 is electrically connected to the chamber body 131 via a wiring 137a. The anode 500 supported by the ground plate 137 is connected to the ground potential via the ground plate 137, the wiring 137a, and the chamber body 131.

[0027] An anode-side cover 550 that covers the side of the anode 500 is disposed on the ground plate 137. The anode-side cover 550 includes cover members 551, 553, and 555, which are arranged in this order from upstream to downstream in the laser gas flow. The cover member 551 is fixed to the ground plate 137 with bolts (not shown). A preionization electrode 10 is provided between the cover members 551 and 553, and the cover members 553 and 555 sandwich the anode 500. The anode 500 is fixed to the ground plate 137 with bolts (not shown), and the cover members 553 and 555 are fixed to the anode 500 with bolts (not shown). The cover members 551, 553, and 555 can be made of, for example, porous nickel metal that has low reactivity with F2 gas. Cover members 551, 553, and 555 guide the laser gas so that the laser gas flows from cross flow fan 149 to heat exchanger 151 via the discharge space due to the blowing of cross flow fan 149.

[0028] The preionization electrode 10 is provided on the ground plate 137 to the side of the anode 500 in the H direction. In this example, the preionization electrode 10 is provided upstream of the anode 500. The preionization electrode 10 includes a dielectric pipe 11, a preionization inner electrode, and a preionization outer electrode. Hereinafter, the preionization inner electrode and the preionization outer electrode may be referred to as the inner electrode 13 and the outer electrode 15, respectively.

[0029] The dielectric pipe 11 is, for example, a cylindrical member, and extends along the Z direction. Examples of materials for the dielectric pipe 11 include alumina ceramics and sapphire.

[0030] The inner electrode 13 is rod-shaped, disposed inside the dielectric pipe 11, and extends along the longitudinal direction of the dielectric pipe 11. Examples of materials for the inner electrode 13 include copper and brass.

[0031] The outer electrode 15 is disposed between the dielectric pipe 11 and the cover member 553 and extends along the longitudinal direction of the dielectric pipe 11. The outer electrode 15 includes an end portion 15a facing a portion of the outer peripheral surface of the dielectric pipe 11. This end portion 15a is provided from one end of the outer electrode 15 to the other end in the longitudinal direction of the outer electrode 15. The outer electrode 15 is bent in a plane perpendicular to the longitudinal direction of the dielectric pipe 11, and due to the bending, the end portion 15a contacts the outer peripheral surface of the dielectric pipe 11 so as to press against the outer peripheral surface of the dielectric pipe 11. A portion of the outer peripheral surface of the dielectric pipe 11 substantially opposite to the contact portion with the end portion 15a of the outer electrode 15 contacts the cover member 551. Therefore, even when the outer electrode 15 presses against the dielectric pipe 11, the dielectric pipe 11 is supported by the cover member 551. A screw hole (not shown) is provided at the end of the outer electrode 15 opposite to the end 15a, and the outer electrode 15 is fixed to the cover member 553 by a screw (not shown) that is threaded into the screw hole. Therefore, it can be understood that the outer electrode 15 is fixed to the anode 500 via the cover member 553. Examples of materials for the outer electrode 15 include copper and brass.

[0032] A pair of cathode-side cover parts 450 are arranged on the surface of the electrical insulator 135 facing the internal space of the chamber body 131. The cathode-side cover parts 450 are arranged on the upstream and downstream sides of the cathode 400, respectively, and extend in the Z direction along the cathode 400, and are separate from each other. Each cathode-side cover part 450 is fixed to the electrical insulator 135 with a bolt (not shown). The cross-sectional shape of the cathode-side cover part 450 is roughly a right triangle, and the cathode-side cover part 450 gradually becomes higher in the V direction as it approaches the cathode 400 in the H direction. Similar to the anode-side cover part 550, such cathode-side cover parts 450 guide the laser gas.

[0033] 2 includes a housing 145a, a prism 145b arranged in the internal space of the housing 145a, a grating 145c, and a rotation stage (not shown). An opening is formed in the housing 145a, and the housing 145a is connected to the rear side of the chamber main body 131 via the opening.

[0034] Prism 145b expands the beam width of light emitted from window 139a and makes the light incident on grating 145c. Prism 145b also reduces the beam width of light reflected from grating 145c and returns the light to the internal space of chamber main body 131 via window 139a. Prism 145b is supported on a rotation stage and rotates by the rotation stage. Rotation of prism 145b changes the angle of incidence of the light with respect to grating 145c. Therefore, rotation of prism 145b makes it possible to select the wavelength of light returning from grating 145c to chamber main body 131 via prism 145b. While FIG. 2 shows an example in which one prism 145b is arranged, it is sufficient that at least one prism is arranged.

[0035] The surface of the grating 145c is made of a highly reflective material and has numerous grooves formed at regular intervals. The cross-sectional shape of each groove is, for example, a right-angled triangle. When light entering the grating 145c from the prism 145b is reflected by these grooves, it is diffracted in a direction corresponding to the wavelength of the light. The grating 145c is Littrow-oriented so that the angle of incidence of the light entering the grating 145c from the prism 145b matches the angle of diffraction of the diffracted light of the desired wavelength. This allows light near the desired wavelength to be returned to the chamber body 131 via the prism 145b.

[0036] Output coupling mirror 147 is disposed in the internal space of optical path pipe 147a connected to the front side of chamber main body 131, and faces window 139b. Output coupling mirror 147 transmits a portion of the laser light emitted from window 139b toward monitor module 160, and reflects the other portion back into the internal space of chamber main body 131 via window 139b. In this way, grating 145c and output coupling mirror 147 form a Fabry-Perot type laser resonator, and chamber main body 131 is disposed on the optical path of the laser resonator.

[0037] The monitor module 160 is disposed on the optical path of the laser light emitted from the output coupling mirror 147. The monitor module 160 includes a housing 161, and a beam splitter 163 and an optical sensor 165 that are disposed in the internal space of the housing 161. An opening is formed in the housing 161, and the internal space of the housing 161 communicates with the internal space of the optical path pipe 147a through this opening.

[0038] Beam splitter 163 transmits a portion of the laser light emitted from output coupling mirror 147 toward shutter 170, and reflects another portion of the laser light toward the light-receiving surface of optical sensor 165. Optical sensor 165 measures the energy E of the laser light incident on the light-receiving surface, and outputs a signal indicating the measured energy E to laser processor 190.

[0039] The laser processor 190 of the present disclosure is a processing device including a storage device 190a storing a control program and a CPU (Central Processing Unit) 190b that executes the control program. The laser processor 190 is specially configured or programmed to execute various processes included in the present disclosure. The laser processor 190 also controls the entire gas laser apparatus 100.

[0040] The laser processor 190 transmits and receives various signals to and from the exposure processor 230 of the exposure apparatus 200. For example, the laser processor 190 receives signals indicating a light emission trigger Tr and a target energy Et, which will be described later, from the exposure processor 230. The target energy Et is a target value for the energy of the laser light used in the exposure process. The laser processor 190 controls the charging voltage of the charger 141 based on the energy E and the target energy Et received from the optical sensor 165 and the exposure processor 230. The energy of the laser light is controlled by controlling this charging voltage. The laser processor 190 also transmits a command signal to the pulse power module 143 to turn on or off the switch 143a. The laser processor 190 is also electrically connected to the shutter 170 and controls the opening and closing of the shutter 170.

[0041] The laser processor 190 keeps the shutter 170 closed until the difference ΔE between the energy E received from the monitor module 160 and the target energy Et received from the exposure processor 230 falls within an allowable range. When the difference ΔE falls within the allowable range, the laser processor 190 sends a reception ready signal to the exposure processor 230 notifying it that it is ready to receive the light emission trigger Tr. Upon receiving the reception ready signal, the exposure processor 230 sends a signal indicating the light emission trigger Tr to the laser processor 190, and upon receiving the signal indicating the light emission trigger Tr, the laser processor 190 opens the shutter 170. The light emission trigger Tr is defined by a predetermined repetition frequency f of the laser light and a predetermined pulse number P, and is a timing signal that the exposure processor 230 uses to cause the laser oscillator 130 to oscillate the laser, and is an external trigger. The repetition frequency f of the laser light is, for example, 100 Hz or more and 10 kHz or less.

[0042] The shutter 170 is disposed in the optical path of the laser light in the internal space of the optical path pipe 171, which communicates with an opening formed on the side of the housing 161 of the monitor module 160 opposite to the side to which the optical path pipe 147a is connected. Purge gas is supplied to and filled into the internal spaces of the optical path pipes 171 and 147a and the internal spaces of the housings 161 and 145a. The purge gas includes an inert gas such as nitrogen (N2). The purge gas is supplied from a purge gas supply source (not shown) through piping (not shown). The optical path pipe 171 also communicates with the exposure device 200 through an opening in the housing 110 and an optical path pipe 300 that connects the housing 110 and the exposure device 200. The laser light that has passed through the shutter 170 enters the exposure device 200.

[0043] The exposure processor 230 of the present disclosure is a processing device including a storage device 230a that stores a control program and a CPU 230b that executes the control program. The exposure processor 230 is specially configured or programmed to execute the various processes included in the present disclosure. The exposure processor 230 also controls the entire exposure apparatus 200.

[0044] FIG. 4 is a cross-sectional view perpendicular to the optical axis of the laser light around the cathode 400 and anode 500 shown in FIG. 3. In FIG. 4, the laser gas flowing through the discharge space is indicated by a thick arrow. The cathode 400 includes a base portion 401 and a discharge portion 403 protruding from the base portion 401 toward the anode 500. Of the cathode 400, the base portion 401 is fixed to the electrical insulator 135 by a conductive member 157. The base portion 401 and the discharge portion 403 extend longitudinally along the Z direction and have the same length as the cathode 400 in the Z direction. The base portion 401 is wider in the H direction than the discharge portion 403, and surfaces 407a of the base portion 401 are located on both sides of the discharge portion 403 in the H direction. In FIG. 4, for ease of viewing, only one surface 407a is labeled. A side surface of the base portion 401 along the VZ plane abuts against a part of a side surface 451 of the cathode-side cover portion 450. Another part of the side surface 451 does not abut against the cathode 400, and a space is provided between the other part of the side surface 451 and a side surface 403a of the discharge portion 403 along the VZ plane. Furthermore, the discharge portion 403 extends toward the anode 500 beyond a base facing portion 453 (described later) of the cathode-side cover portion 450. Therefore, the end portion of the discharge portion 403 on the anode 500 side is located closer to the anode 500 than the cathode-side cover portion 450. Note that the cathode 400 is simply illustrated in FIG. 2 .

[0045] The base facing portion 453 of the cathode-side cover portion 450 is connected to a portion of the side surface 451 of the cathode-side cover portion 450 and extends in the H direction toward the side surface of the discharge portion 403. The base facing portion 453 is spaced apart from the base portion 401 in the V direction and overlaps with a portion of the base portion 401, and is spaced apart from the discharge portion 403 in the H direction and overlaps with a portion of the discharge portion 403. The base facing portion 453 also extends in the Z direction and has approximately the same length as the cathode 400 in the Z direction. The base facing portion 453 covers a portion of the base portion 401, and a gap 40 is provided between the base facing portion 453 and the surface 407a of the base portion 401. The gap 40 is a generally L-shaped space surrounded by an entrance 41 of the gap 40 provided between the side surface of the discharge unit 403 and the base facing portion 453, the base facing portion 453, the side surface 451, the surface 407a, and the side surface of the discharge unit 403. Such a gap 40 can prevent the cathode 400 and the cathode-side cover portion 450 from being unable to be assembled due to interference caused by dimensional errors in manufacturing between the cathode 400 and the cathode-side cover portion 450. The cathode-side cover portion 450, which forms the gap 40, covers a portion of the cathode 400 from the side.

[0046] The cathode-side cover portion 450 is provided on both the upstream and downstream sides of the flow of laser gas in the cathode 400. Therefore, the gap 40 is provided separately on both the upstream and downstream sides of the flow of laser gas in the cathode 400. For ease of viewing, reference numerals are attached to only one of the gaps 40 and inlet 41 in Figures 3 and 4. The acoustic wave 61a shown in Figure 4 will be described later.

[0047] The chamber body 131 of this comparative example is provided with a cathode-side sound-absorbing member 470 in each gap 40 on the upstream side and downstream side of the laser gas flow in the cathode 400. The cathode-side sound-absorbing member 470 is made of, for example, a porous material. Examples of materials for the cathode-side sound-absorbing member 470 include metals such as nickel, copper, iron, stainless steel, and brass. Note that the cathode-side sound-absorbing member 470 may be an electrical insulator as long as it is made of a porous material, and examples of materials for such cathode-side sound-absorbing member 470 include alumina ceramics.

[0048] As shown in FIG. 4, the base portion 401 of this comparative example includes a first base portion 405 and a second base portion 407. The dashed line in FIG. 4 is a virtual boundary line separating the first base portion 405 and the second base portion 407. Hereinafter, this boundary line will be omitted. The second base portion 407 is provided on the side of the first base portion 405 opposite the electrical insulation portion 135. The second base portion 407 protrudes from the first base portion 405 toward the anode 500. The first base portion 405 is wider in the H direction than the second base portion 407, and faces 405a of the first base portion 405 are provided at positions sandwiching the second base portion 407 in the H direction. The discharge portion 403 is provided on the side of the second base portion 407 opposite the first base portion 405 side. The discharge portion 403 protrudes from the second base portion 407 toward the anode 500. The second base portion 407 is wider in the H direction than the discharge portion 403, and faces 407a of the second base portion 407 are provided at positions sandwiching the discharge portion 403 in the H direction. The faces 407a face the inlet 41, and when the cathode 400 is viewed along the V direction, the faces 407a are exposed from the inlet 41. In FIG. 4, for ease of viewing, only one face 405a, 407a is labeled. The first base portion 405 abuts against a portion of a side surface 451 of the cathode-side cover portion 450, and the second base portion 407 does not abut against the side surface 451. In other words, the cathode-side cover portion 450 is separated from the second base portion 407, which is part of the base portion 401. The first base portion 405 and the second base portion 407 are disposed closer to the electrical insulating portion 135 than the inlet 41.

[0049] The cathode-side sound-absorbing member 470 of this comparative example is disposed on the base portion 401. Specifically, the cathode-side sound-absorbing member 470 is disposed on the surface 405a of the first base portion 405 and is screwed to the first base portion 405. The cathode-side sound-absorbing member 470 is disposed in the gap 40 between the second base portion 407, which is part of the base portion 401, and the side surface 451 of the cathode-side cover portion 450, and abuts against the side surface of the second base portion 407 and faces the base-facing portion 453 and part of the entrance 41 of the gap 40.

[0050] 2.2 Operation Next, the operation of the gas laser device 100 of the comparative example will be described.

[0051] Before the gas laser device 100 emits laser light, the internal spaces of the optical path pipes 147a, 171, and 300 and the internal spaces of the housings 145a and 161 are filled with purge gas from a purge gas supply source (not shown). Laser gas is supplied to the internal space of the chamber body 131 from a laser gas supply source (not shown). When the laser gas is supplied, the laser processor 190 controls the motor 149a to rotate the crossflow fan 149. The rotation of the crossflow fan 149 circulates the laser gas within the internal space of the chamber body 131. The laser gas is guided from the crossflow fan 149 toward the discharge space by the upstream cathode-side cover portion 450 and cover members 551 and 553. The laser gas is also guided from the discharge space toward the heat exchanger 151 by the downstream cathode-side cover portion 450 and cover member 555.

[0052] When the gas laser apparatus 100 emits laser light, the laser processor 190 receives a signal indicating the target energy Et and a signal indicating the light emission trigger Tr from the exposure processor 230. The laser processor 190 also turns on the switch 143a of the pulse power module 143. This causes the pulse power module 143 to apply a pulsed high voltage between the cathode 400 and the anode 500 and between the inner electrode 13 and the outer electrode 15 from the electrical energy stored in a charging capacitor (not shown). When a high voltage is applied between the inner electrode 13 and the outer electrode 15, a corona discharge occurs near the dielectric pipe 11 and the end 15a, and ultraviolet light is emitted. When the ultraviolet light irradiates the laser gas between the cathode 400 and the anode 500, the laser gas between the cathode 400 and the anode 500 is preionized. After preionization, when the voltage between cathode 400 and anode 500 reaches the breakdown voltage, a main discharge occurs between cathode 400 and anode 500. This generates excimers from the laser medium contained in the laser gas between cathode 400 and anode 500, and they emit light when dissociated. This light travels back and forth between grating 145c and output coupling mirror 147 and is amplified each time it passes through the discharge space in the internal space of chamber body 131, resulting in laser oscillation. A portion of the laser light then passes through output coupling mirror 147 as pulsed laser light and proceeds to beam splitter 163.

[0053] A portion of the laser light that has traveled to beam splitter 163 is reflected by beam splitter 163 and received by optical sensor 165. Optical sensor 165 measures the energy E of the received laser light and outputs a signal indicating the energy E to laser processor 190. Laser processor 190 controls the charging voltage so that the difference ΔE between the energy E and the target energy Et falls within an allowable range. Another portion of the laser light that has traveled to beam splitter 163 passes through beam splitter 163 and shutter 170, and travels to exposure device 200.

[0054] In gas laser device 100, a high-temperature, high-pressure state is generated in the discharge space in an extremely short time by the main discharge between cathode 400 and anode 500. This generates acoustic waves 61a in the discharge space, which are indicated by the solid curved lines in Figure 4. Acoustic waves 61a are compression waves of the laser gas in chamber body 131, and propagate within chamber body 131 while spreading from the discharge space. The propagation speed is approximately 500 m / s.

[0055] In this comparative example, the region of the gap 40 through which the acoustic wave 61a propagates is a space surrounded by the inlet 41, the base facing portion 453, the side surface 451, the surface 405a, the surface 407a of the second base portion 407 facing the base facing portion 453, and the side surface of the discharge portion 403. This gap 40 is composed of the inlet 41, a first space connected to the inlet 41 and having a rectangular cross section in the Z direction, and a second space connected to the first space, located deeper than the first space, and having a rectangular cross section extending in the H direction. The cathode-side sound-absorbing member 470 extends along the Z direction and has approximately the same length as the cathode 400, but may be shorter than the cathode 400. The cathode-side sound-absorbing member 470 abuts against the second base portion 407 and the side surface 451, and is disposed in the gap 40 separated from the base facing portion 453. The cathode-side sound-absorbing member 470 absorbs the acoustic waves 61a that have propagated through the gap 40. The absorbed acoustic waves 61a propagate while repeatedly reflecting inside the cathode-side sound-absorbing member 470, where they are converted into energy such as heat and are gradually attenuated. Furthermore, the acoustic waves 61a that have passed through the cathode-side sound-absorbing member 470 are reflected by the base portion 401 and the cathode-side cover portion 450 around the cathode-side sound-absorbing member 470, and are again absorbed by the cathode-side sound-absorbing member 470. The absorbed acoustic waves 61a are repeatedly reflected inside the cathode-side sound-absorbing member 470, as described above, and are further attenuated.

[0056] 3. Challenges 5 is a cross-sectional view perpendicular to the optical axis of the laser light around the cathode 400. Acoustic wave 61a propagating from inlet 41 to gap 40 may be reflected by surface 407a of second base portion 407 and return to the discharge space as reflected wave 61b, as shown in FIG.

[0057] If reflected wave 61b propagates into the discharge space at the timing when the main discharge occurs, reflected wave 61b may change the density distribution of the laser gas in the discharge space, making the main discharge unstable and reducing the stability of the energy of the laser light emitted from gas laser device 100. In this way, reflected wave 61b may affect the performance of the laser light. In an operating environment where the repetition frequency f of the laser light is, for example, 8.5 kHz or higher, the discharge may occur at a timing when reflected wave 61b has not yet sufficiently attenuated, which may cause the main discharge to become unstable.

[0058] Therefore, in the following embodiment, a chamber device CH of a gas laser device 100 that can output laser light with stable pulse energy even at a high repetition rate will be exemplified.

[0059] 4. Description of Embodiment 1 Next, the chamber apparatus CH of embodiment 1 will be described. Note that the same components as those described above are given the same reference numerals, and duplicate descriptions will be omitted unless otherwise specified. Also, in some drawings, for clarity, some components may be omitted or simplified, and similar components may be given reference numerals only in part, with some reference numerals omitted.

[0060] 4.1 Configuration 6 is a cross-sectional view of the periphery of the cathode 400 in this embodiment, taken perpendicular to the optical axis of the laser light. The chamber apparatus CH of this embodiment differs from the chamber apparatus CH of the comparative example in that it includes an inclined portion 480. Note that hatching of the base portion 401 is omitted in FIGS. 6 to 22.

[0061] In this embodiment, the inclined portions 480 are arranged on both sides of the discharge portion 403 in the H direction. The longitudinal direction of the inclined portions 480 extends along the Z direction. In this embodiment, the inclined portions 480 are formed integrally with the base portion 401 and the discharge portion 403. In other words, the inclined portions 480 are made of the same material as the base portion 401 and the discharge portion 403, and no seams are formed between the inclined portions 480 and the base portion 401 and between the inclined portions 480 and the discharge portion 403.

[0062] The inclined portion 480 has an inclined surface 480a. The inclined surface 480a is closer to the base portion 401 than the base facing portion 453 in the V direction, and at least a portion of the inclined surface 480a is disposed in a space that is closer to the discharge portion 403 than the base facing portion 453 in the H direction. The inclined surface 480a widens in a direction away from the discharge portion 403 when extending in a direction from the discharge portion 403 side toward the base portion 401 side along the V direction.

[0063] In this embodiment, the base facing portion 453 and the base-side end 480b of the inclined surface 480a do not overlap in the V direction. When viewing the inclined surface 480a from the anode 500 side along the V direction, the distance in the H direction between the base facing portion 453 and the base-side end 480b, which is located between the discharge portion 403 and the base facing portion 453 and is the farthest from the discharge portion 403, is defined as a, and the distance in the V direction between the base facing portion 453 and the surface 407a of the second base portion 407 facing the base facing portion 453 is defined as b. Then, the acute angle θ formed by the inclined surface 480a and the surface 407a of the second base portion 407 facing the base facing portion 453 satisfies the following formula (1): TIFF2025166435000002.tif16170

[0064] In addition, in the base portion 401, the distance in the V direction between the surface 407a facing the base facing portion 453 and the position 480c on the inclined surface 480a closest to the anode 500 is preferably equal to or less than b.

[0065] 4.2 Actions and Effects In chamber body 131 of the present embodiment, acoustic waves 61a reflected by inclined surface 480a can be reflected by the surface of base facing portion 453 on the base portion 401 side, and therefore acoustic waves 61a can be guided to gap 40 formed between cathode-side cover portion 450 and base portion 401, and can be absorbed by cathode-side sound-absorbing member 470 disposed in gap 40. Therefore, reflected waves 61b returning to the discharge space can be reduced, and chamber body 131 of gas laser device 100 can be realized that is capable of outputting laser light with stable pulse energy even at high repetition frequencies.

[0066] 7 is a diagram showing an example in which acoustic wave 61a is reflected by inclined surface 480a and guided into gap 40. After being reflected by inclined surface 480a, acoustic wave 61a is reflected by surface 453a of base opposing portion 453 on the base portion 401 side, and is guided deep into gap 40. As a result, acoustic wave 61a is more likely to reach cathode-side sound-absorbing member 470.

[0067] 8 is a diagram showing another example in which acoustic wave 61a is reflected by inclined surface 480a and guided into gap 40. Acoustic wave 61a is reflected by inclined surface 480a, and then reflected by surface 407a of base portion 401, and then reflected by surface 453a of base opposing portion 453 facing base portion 401, and is guided deep into gap 40. As a result, acoustic wave 61a is more likely to reach cathode-side sound-absorbing member 470.

[0068] Furthermore, in the chamber body 131 of this embodiment, the distance between the inclined surface 480a and the base facing portion 453 can be prevented from becoming narrow, making it easier to guide the acoustic wave 61a into the gap 40.

[0069] In the chamber body 131 of this embodiment, the inclined portion 480 is integral with at least one of the discharge portion 403 and the base portion 401, and therefore no fastening material is required to fix the inclined portion 480. As a result, unevenness is less likely to occur on the inclined surface 480a. As a result, the acoustic wave 61a is reflected by the inclined surface 480a and more easily reaches the gap 40, and more easily reaches the cathode-side sound-absorbing member 470 arranged in the gap 40, making it easier for the acoustic wave to be absorbed.

[0070] In the chamber body 131 of this embodiment, the inclined portions 480 are arranged symmetrically on both sides of the discharge unit 403 in the H direction, but this is not limiting. That is, the inclined portions 480 may be provided only on the −H direction side with respect to the discharge unit 403, or may be provided only on the +H direction side with respect to the discharge unit 403. Furthermore, the inclined portions 480 on the +H direction side and the inclined portions 480 on the −H direction side may have different shapes.

[0071] In the chamber body 131 of the present embodiment, the angle θ of the inclined portion 480 satisfies formula (1), but is not limited to this. It is sufficient that at least a part of the inclined surface 480a is disposed in a space that is closer to the base portion 401 than the base facing portion 453 in the V direction and closer to the discharge portion 403 than the base facing portion 453 in the H direction.

[0072] In addition, in the present embodiment, an example has been shown in which the cathode-side cover part 450 and the base-side end part 480b of the inclined surface 480a do not overlap in the V direction, but this is not limiting. For example, as shown in Fig. 9, the cathode-side cover part 450 and the base-side end part 480b of the inclined surface 480a may overlap in the V direction. In this case, a = 0 in equation (1), and equation (1) is modified to 0° < θ < 90°.

[0073] 4.3 First Modification of the First Embodiment 4.3.1 Configuration 10 is a perspective view of the inclined portion 480 in this modification. In this modification, the inclined portion 480 differs from the chamber body 131 in embodiment 1 in that it is separate from the cathode 400. In this modification, the inclined portion 480 is a triangular prism whose VH cross section has a right-angled triangular shape. The inclined portion 480 may be fixed to the chamber body 131 with bolts (not shown).

[0074] 4.3.2 Actions and Effects Inclined portion 480 can be retrofitted to an existing gas laser device 100. Furthermore, if discharge products adhere to inclined surface 480a, it can be replaced with an inclined portion 480 having a clean surface with minimal irregularities. This suppresses diffuse reflection of acoustic wave 61a due to discharge products adhering to the surface of inclined portion 480, allowing for easy and low-cost restoration to a state in which acoustic wave 61a is effectively absorbed.

[0075] Depending on the intensity and spatial distribution of the acoustic wave 61a entering the entrance 41 of the gap 40, an inclined portion 480 having inclined surfaces with different shapes on the -H direction side and the +H direction side of the discharge portion 403 may be provided.

[0076] In this modification, the inclined portion 480 is a triangular prism whose VH cross section has a right-angled triangle shape, but is not limited to this. For example, it may be an isosceles right triangle, a trapezoid, or a rectangle.

[0077] 4.4 Second Modification of the First Embodiment 4.4.1 Configuration 11 is a diagram showing a base facing portion 453 according to this modification. The base facing portion 453 of this modification differs from the chamber body 131 of the first embodiment in that the edge corner on the base portion 401 side of the base facing portion 453 is chamfered.

[0078] 4.4.2 Actions and Effects Acoustic waves 61a reflected by inclined surface 480a are more likely to be reflected by chamfered surface 453c rather than by end surface 453b of base facing portion 453. This makes it easier for acoustic waves 61a to reach gap 40 and cathode-side sound-absorbing member 470 disposed in gap 40, making it easier for the acoustic waves 61a to be absorbed.

[0079] 4.5 Third Modification of the First Embodiment 4.5.1 Configuration FIG. 12 is a cross-sectional view perpendicular to the optical axis of the laser beam around the cathode 400 according to this modified example. In this modified example, the distance d2 between the base facing portion 453 and the inclined surface 480a is different from that of the chamber body 131 of the first embodiment in that it is not less than the distance d1 between the base facing portion 453 and the discharge portion 403. It is preferable that d1 is in the range of 0.4 mm < d1 < 5 mm.

[0080] 4.5.2 Operation and Effect Since the distance between the inclined surface 480a and the base facing portion 453 can be increased, the acoustic wave 61a can be more easily guided into the gap 40.

[0081] 4.6 Fourth Modified Example of the First Embodiment 4.6.1 Configuration FIG. 13 is a cross-sectional view perpendicular to the optical axis of the laser beam around the cathode 400 according to the fourth modified example of the first embodiment. In this modified example, the thickness of the cathode side sound absorbing member 470 in the V direction is large, and the distance in the V direction between the surface 453a of the base facing portion 453 and the virtual plane T including the surface 470a of the cathode side sound absorbing member 470 facing the base facing portion 453, indicated by a broken line, is small, which is different from that of the chamber body 131 of the first embodiment.

[0082] 4.6.2 Operation and Effect Since the distance between the cathode side sound absorbing member 470 disposed on the base portion 401 and the base facing portion 453 is reduced, the area of the side surface 451 on the gap 40 side of the cathode side cover portion 450 can be reduced. Therefore, the acoustic wave 61a reflected by the side surface 451 and returning to the discharge region can be reduced. Also, in the gap 40, since the volume occupied by the cathode side sound absorbing member 470 increases, the sound absorbing effect is improved.

[0083] 5. Description of the Second Embodiment Next, the chamber body 131 of the second embodiment will be described. Note that the same components as those described above are given the same reference numerals, and duplicate descriptions will be omitted unless otherwise specified. Also, in some drawings, for ease of viewing, some components may be omitted or simplified, and similar components may be given reference numerals only in some cases, and some reference numerals may be omitted.

[0084] 5.1 Configuration 14 is a cross-sectional view perpendicular to the optical axis of the laser light around the cathode 400 according to the second embodiment. The chamber body 131 of this embodiment differs from the other embodiments in that a slit structure 410 is provided on the surface 405a of the first base portion 405 on which the cathode-side sound-absorbing member 470 is disposed. The slit extends in the Z direction and the H direction along the cathode-side sound-absorbing member 470. The depth of the slit is preferably 1.7 mm to 2 mm.

[0085] The structure provided on surface 405a does not have to be regular slit structure 410, and may be a structure having irregularities of random depth.

[0086] 5.2 Actions and Effects Acoustic waves 61a transmitted through cathode-side sound-absorbing member 470 are diffusely reflected by the uneven structure provided on first base portion 405, so acoustic waves 61a are less likely to reinforce each other compared to when surface 405a of base portion 401 is flat. This makes it possible to suppress disturbances in the laser gas distribution in the discharge space.

[0087] 6. Description of Embodiment 3 Next, the chamber body 131 of the third embodiment will be described. Note that the same components as those described above are assigned the same reference numerals, and duplicate descriptions will be omitted unless otherwise specified. Also, in some drawings, for ease of viewing, some components may be omitted or simplified, and similar components may be assigned reference numerals only to some of them, with some reference numerals omitted.

[0088] 6.1 Configuration Fig. 15 is a cross-sectional view perpendicular to the optical axis of the laser light around the cathode 400 according to the third embodiment. Fig. 16 is a cross-sectional view taken along the line AA in Fig. 15. That is, Fig. 16 is a diagram showing the relationship in thickness between the cathode-side sound-absorbing member 470 and the first base portion 405 on which the cathode-side sound-absorbing member 470 is disposed. Fig. 17 is a cross-sectional view taken along the line BB in Fig. 16. Fig. 18 is a cross-sectional view taken along the line CC in Fig. 16. Fig. 19 is a cross-sectional view taken along the line DD in Fig. 16. In this embodiment, the thickness in the V direction of the first base portion 405 on which the cathode-side sound-absorbing member 470 is disposed increases from the DD side toward the BB side in the Z direction. The thickness in the V direction of the cathode-side sound-absorbing member 470 decreases from the DD side toward the BB side in the Z direction.

[0089] 6.2 Actions and Effects It is possible to shift the phase of acoustic wave 61a reflected from first base portion 405 along the Z direction, which disperses the change in density distribution of the laser gas over time, making it possible to suppress the change in density distribution of the laser gas during main discharge, and thus making it possible to suppress unstable main discharge.

[0090] In this embodiment, the V-direction thickness of the first base portion 405 on which the cathode-side sound-absorbing member 470 is disposed and the V-direction thickness of the cathode-side sound-absorbing member 470 change continuously, but this is not limiting. For example, the thickness may change in a stepwise manner.

[0091] 7. Description of Embodiment 4 Next, the chamber body 131 of the fourth embodiment will be described. Note that the same components as those described above are given the same reference numerals, and duplicate descriptions will be omitted unless otherwise specified. Also, in some drawings, for ease of viewing, some components may be omitted or simplified, and similar components may be given reference numerals only in some cases, and some reference numerals may be omitted.

[0092] 7.1 Configuration 20 is a cross-sectional view perpendicular to the optical axis of the laser light around the cathode 400 according to embodiment 4. The chamber body 131 of this embodiment differs from the other embodiments in that the cathode-side sound absorbing member 470 is disposed on the surface of the base opposing portion 453 facing the base portion 401.

[0093] 7.2 Actions and Effects Acoustic wave 61a propagated into gap 40 is absorbed by cathode side sound absorbing member 470. Therefore, the magnitude of reflected wave 61b is reduced, and a decrease in the stability of the laser light emitted from gas laser device 100 is suppressed.

[0094] 8. Description of Embodiment 5 Next, a description will be given of the chamber body 131 of the fifth embodiment. Note that the same components as those described above are given the same reference numerals, and duplicate descriptions will be omitted unless otherwise specified. Also, in some drawings, for ease of viewing, some components may be omitted or simplified, and similar components may be given reference numerals only in some cases, and some reference numerals may be omitted.

[0095] 8.1 Configuration 21 is a cross-sectional view perpendicular to the optical axis of the laser light around the cathode 400 according to the fifth embodiment. The chamber body 131 of this embodiment differs from the other embodiments in that the base facing portion 453 of the cathode side cover part 450 is a conductive sound absorbing member 459. Note that the entire base facing portion 453 does not have to be made of a conductive sound absorbing member 459, and a portion of the surface of the base facing portion 453 on the anode 500 side may include the conductive sound absorbing member 459.

[0096] 8.2 Actions and Effects Since the acoustic wave 61a reflected by the anode side surface of the cathode side cover part 450 can be attenuated, changes in the density distribution of the laser gas can be suppressed, and the main discharge can be prevented from becoming unstable.

[0097] 9. Description of Embodiment 6 The chamber body 131 of Embodiment 6 will be described. For configurations similar to those described above, the same reference numerals will be used, and redundant descriptions will be omitted unless otherwise specifically described. Also, in some drawings, for ease of viewing, part of a member may be omitted or simplified, and for similar components, reference numerals may be attached only to a part, and some reference numerals may be omitted.

[0098] 9.1 Configuration FIG. 22 is a cross-sectional view perpendicular to the optical axis of the laser beam around the cathode 400 in the present embodiment. The chamber body 131 of the present embodiment is different from that of Embodiment 1 in that the cathode-side sound-absorbing member 470 is exposed in the V direction. In this case, the distance d1 between the base facing portion 453 and the discharge portion 403, which is the size of the inlet 41 of the gap 40, satisfies 0.4 mm < d1 < 5 mm, and in the H direction, a part of the cathode-side cover portion 450 is separated from the base portion 401, and it is preferable that the length dx of the gap 40 in the H direction satisfies dx ≧ d1.

[0099] 9.2 Operation and Effect It is possible to reduce the reflection of the acoustic wave 61a on the surface of the base facing portion 453 on the anode 500 side. Also, it is possible to prevent the laser gas distribution in the discharge space near the discharge portion 403 from being disturbed. Further, even in the structure where the cathode-side sound-absorbing member 470 is exposed in the V direction, since the gap 40 extends in the H direction and the V direction, the opportunity for the acoustic wave 61a entering the gap 40 to be reflected by the cathode-side cover portion 450 increases, and the acoustic wave 61a easily reaches the cathode-side sound-absorbing member 470.

[0100] 10. Description of Embodiment 7 The chamber body 131 of Embodiment 7 will be described. For configurations similar to those described above, the same reference numerals will be used, and redundant descriptions will be omitted unless otherwise specifically described. Also, in some drawings, for ease of viewing, part of a member may be omitted or simplified, and for similar components, reference numerals may be attached only to a part, and some reference numerals may be omitted.

[0101] Note that, in the chamber body 131 of Embodiment 7, the configuration on the anode 500 side is mainly described, but the configuration on the cathode 400 side may be any of the configurations on the cathode 400 side in other embodiments and their modifications.

[0102] 10.1 Configuration FIG. 23 is a cross-sectional view perpendicular to the optical axis of the laser light around the anode 500 according to Embodiment 7. In the chamber body 131 of the present embodiment, since the cover member 555 is separated from the anode 500, it is different from other embodiments in that a gap 50 is provided between the anode 500 and the cover member 555. The gap 50 is a substantially L-shaped space surrounded by an inlet 51 of the gap 50 provided between the side surface of the anode 500 and the cover base facing portion 554, the cover base facing portion 554, the side surface 552 of the cover member 555, the cover base portion 557, and the side surface of the anode 500. Such a gap 50 can prevent the anode 500 and the cover member 555 from being unable to be assembled due to interference caused by dimensional errors in the manufacture of the anode 500 and the cover member 555. The cover member 555 forming the gap 50 covers the anode 500 from the side.

[0103] The cover base facing portion 554 of the cover member 555 is separated from the cover base portion 557, which is a part of the cover member 555, in the V direction and protrudes in the H direction from the side surface 552 toward the side surface of the anode 500. The cover base facing portion 554 is separated from the anode 500 in the H direction. The cover base facing portion 554 extends in the Z direction and has substantially the same length as the anode 500 in the Z direction.

[0104] Note that the distance d3 between the cover base facing portion 554 and the anode 500 preferably satisfies 0.4 mm < d3 < 5 mm.

[0105] The chamber body 131 of this embodiment differs from the other embodiments and their modifications in that the chamber body 131 further includes an anode-side sound-absorbing member 570 provided in the gap 50 between the cover base portion 557 and the cover base opposing portion 554. The configuration and material of the anode-side sound-absorbing member 570 are the same as the configuration and material of the cathode-side sound-absorbing member 470.

[0106] The chamber body 131 according to this embodiment also differs from the other embodiments and their modifications in that it includes an anode-side inclined portion 580. The anode-side inclined portion 580 includes an anode-side inclined surface 580a. The anode-side inclined surface 580a is closer to the cover base portion 557 than the cover base facing portion 554 in the V direction, and at least a portion of the anode-side inclined surface 580a is disposed in a space that is closer to the anode 500 than the cover base facing portion 554 in the H direction. The anode-side inclined surface 580a widens in the direction away from the anode 500 when extending in the V direction from the anode 500 side toward the cover base portion 557 side, and extends in the Z direction.

[0107] In this embodiment, the preionization electrode 10 is provided upstream of the anode 500, and therefore the gap 50 is provided downstream of the anode 500, but the gap 50 may also be provided upstream of the anode 500. The gap upstream of the anode 500 may also be provided with an anode-side inclined portion 580 and an anode-side inclined surface 580a similar to those on the downstream side.

[0108] 10.2 Actions and Effects In chamber body 131 of the present embodiment, acoustic waves 61a reflected by anode-side inclined surface 580a can be reflected by the surface of cover base opposing portion 554 on the ground plate 137 side, and can be guided to gap 50, where acoustic waves 61a can be absorbed by anode-side sound-absorbing member 570 disposed in gap 50. This makes it possible to reduce reflected waves 61b returning to the discharge space, and to realize chamber body 131 of gas laser device 100 that can output laser light with stable pulse energy even at high repetition frequencies.

[0109] The above description is intended to be illustrative rather than limiting. Thus, it will be apparent to one skilled in the art that modifications can be made to the disclosed embodiments without departing from the scope of the claims. It will also be apparent to one skilled in the art that the disclosed embodiments can be used in combination.

[0110] For example, in the chamber body 131, the inclined surface 480a is flat, but this is not limiting. For example, the inclined surface 480a may be curved. In addition, in the inclined portion 480, the angle θ satisfies formula (1), but the angle θ does not have to satisfy formula (1). In addition, in the inclined portion 480, the angle θ abuts the discharge unit 403 and the second base unit 407, but this is not limiting. It is sufficient that at least a portion of the inclined surface 480a of the inclined portion 480 is disposed in a space that is closer to the base unit 401 than the base facing portion 453 in the V direction and closer to the discharge unit 403 than the base facing portion 453 in the H direction. The inclined portion 480 may be separated from at least one of the discharge unit 403 and the second base unit 407.

[0111] Terms used throughout this specification and claims should be construed as "open ended" unless expressly stated otherwise. For example, words such as "comprise," "have," "comprise," and "equip" should be construed as meaning "without excluding the presence of elements other than those listed." In addition, the modifier "a" should be construed as meaning "at least one" or "one or more." In addition, the term "at least one of A, B, and C" should be construed as "A," "B," "C," "A+B," "A+C," "B+C," or "A+B+C," and should also be construed as including combinations other than "A," "B," and "C."

Claims

1. A chamber device for a gas laser device, comprising: a chamber body; an anode disposed in the internal space of the chamber body and having a longitudinal direction extending along a predetermined direction; a cathode disposed in the internal space in a first direction facing and away from the anode, the cathode having a longitudinal direction extending along the predetermined direction, the cathode including a base portion and a discharge portion having a width in a second direction perpendicular to the predetermined direction and the first direction that is smaller than that of the base portion and protruding from the base portion toward the anode; a cathode-side cover portion that includes a base facing portion that is spaced apart from the base portion and overlaps with a portion of the base portion in the first direction and that is spaced apart from the discharge portion and overlaps with the discharge portion in the second direction, and that covers a portion of the base portion; a cathode-side sound-absorbing member disposed in a space between the cathode-side cover portion and the base portion; an inclined portion having an inclined surface extending in the predetermined direction, the inclined portion having at least a portion located in a space that is closer to the base portion than the base opposing portion in the first direction and closer to the discharge portion than the base opposing portion in the second direction, the inclined portion expanding in a direction away from the discharge portion when extending in a direction from the discharge portion side toward the base portion side; Equipped with A chamber device for a gas laser device.

2. 2. A chamber device for a gas laser apparatus according to claim 1, When viewing the inclined surface from the anode side along the first direction, if the distance in the second direction between the position on the inclined surface located between the discharge portion and the cathode side cover portion that is farthest from the discharge portion and the base opposing portion is a, and the distance in the first direction between the base opposing portion and the base portion opposing the base opposing portion is b, then the acute angle θ formed by the inclined surface and the surface of the base portion opposing the base opposing portion satisfies the following equation (1).

3. 2. A chamber device for a gas laser apparatus according to claim 1, In the base portion, the distance in the first direction between the surface facing the base opposing portion and the position on the inclined surface closest to the anode is less than or equal to the distance b in the first direction between the base opposing portion and the base portion facing the base opposing portion.

4. 2. A chamber device for a gas laser apparatus according to claim 1, At least one of the discharge portion and the base portion is integral with the inclined portion.

5. 2. A chamber device for a gas laser apparatus according to claim 1, The inclined portion is separate from the cathode.

6. 6. A chamber device for a gas laser device according to claim 5, The inclined portion is a triangular prism whose base is a right triangle.

7. 2. A chamber device for a gas laser apparatus according to claim 1, The inclined portions are disposed on both sides of the discharge portion in the second direction.

8. 2. A chamber device for a gas laser apparatus according to claim 1, The corner of the base facing portion on the side of the base portion is chamfered.

9. 2. A chamber device for a gas laser apparatus according to claim 1, The distance between the end face of the base opposing portion on the discharge portion side and the inclined surface is equal to or greater than the distance between the end face of the base opposing portion on the discharge portion side and the discharge portion.

10. 2. A chamber device for a gas laser apparatus according to claim 1, The cathode-side sound-absorbing member is disposed on the base portion.

11. 11. A chamber device for a gas laser apparatus according to claim 10, The base portion has an uneven structure at a position where the cathode-side sound absorbing member is disposed.

12. 12. The chamber device for a gas laser apparatus according to claim 11, The uneven structure includes a plurality of parallel slits.

13. 2. A chamber device for a gas laser apparatus according to claim 1, In the second direction, at least a portion of the cathode side cover portion is spaced apart from the base portion.

14. 2. A chamber device for a gas laser apparatus according to claim 1, the cathode-side sound-absorbing member is disposed on the base portion facing the base facing portion, The thickness in the first direction of the position where the cathode side sound absorbing member of the base portion is positioned increases from one side to the other side in the specified direction, and the thickness in the first direction of the cathode side sound absorbing member decreases from one side to the other side in the specified direction.

15. 2. A chamber device for a gas laser apparatus according to claim 1, The cathode-side sound-absorbing member is disposed on the surface of the base-facing portion facing the base portion.

16. 2. A chamber device for a gas laser apparatus according to claim 1, The surface of the cathode side cover portion facing the anode side includes a conductive sound absorbing member.

17. 2. A chamber device for a gas laser apparatus according to claim 1, a ground plate disposed in the internal space and supporting the anode from the side opposite to the cathode; an anode-side cover part including a cover base part in contact with the anode, and a cover base opposing part that is spaced apart from the cover base part and overlaps with a part of the cover base part in the first direction, and that is spaced apart from the anode part and overlaps with the anode in the second direction; an anode-side sound-absorbing member disposed in a space between the cover base opposing portion and the cover base portion; an anode-side inclined portion having an anode-side inclined surface that extends in the predetermined direction, the anode-side inclined portion having at least a portion located in a space that is closer to the cover base portion than the cover base facing portion in the first direction and closer to the anode than the cover base facing portion in the second direction, the anode-side inclined portion expanding in a direction away from the anode when extending in a direction from the anode toward the ground plate side; Equipped with A chamber device for a gas laser device.

18. A gas laser device including a chamber device that emits laser light, The chamber device includes a chamber body and an anode disposed in the internal space of the chamber body and having a longitudinal direction extending along a predetermined direction; a cathode disposed in the internal space in a first direction facing and away from the anode, the cathode having a longitudinal direction extending along the predetermined direction, the cathode including a base portion and a discharge portion having a width in a second direction perpendicular to the predetermined direction and the first direction that is smaller than that of the base portion and protruding from the base portion toward the anode; a cathode-side cover portion covering the base portion, the cathode-side cover portion including a base facing portion spaced apart from the base portion in the first direction and overlapping with a part of the base portion, and spaced apart from the discharge portion in the second direction and overlapping with the discharge portion; a cathode-side sound-absorbing member disposed in a space between the cathode-side cover portion and the base portion; a sloped portion having an inclined surface extending in the predetermined direction, the sloped portion having at least a portion disposed in a space that is closer to the base portion than the base opposing portion in the first direction and closer to the discharge portion than the base opposing portion in the second direction, the sloped portion expanding in a direction away from the discharge portion when advancing in a direction from the discharge portion side toward the base portion side.

19. a chamber body; an anode disposed in the internal space of the chamber body and having a longitudinal direction extending along a predetermined direction; a cathode disposed in the internal space in a first direction facing and away from the anode, the cathode having a longitudinal direction extending along the predetermined direction, the cathode including a base portion and a discharge portion having a width in a second direction perpendicular to the predetermined direction and the first direction that is smaller than that of the base portion and protruding from the base portion toward the anode; a cathode-side cover portion covering the base portion, the cathode-side cover portion including a base facing portion spaced apart from the base portion in the first direction and overlapping with a part of the base portion, and spaced apart from the discharge portion in the second direction and overlapping with the discharge portion; a cathode-side sound-absorbing member disposed in a space between the cathode-side cover portion and the base portion; a gas laser apparatus including a chamber apparatus having an inclined portion, at least a portion of which is disposed in a space that is closer to the base portion than the base opposing portion in the first direction and closer to the discharge portion than the base opposing portion in the second direction, and which widens in a direction away from the discharge portion when proceeding in a direction from the discharge portion side to the base portion side, and which has an inclined surface extending in the predetermined direction;

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