Laser chamber apparatus, gas laser apparatus, and electronic device manufacturing method

Abstract

To provide a laser chamber apparatus in which non-uniform wear of a first discharge electrode is suppressed.SOLUTION: A laser chamber apparatus for emitting a laser beam includes: a chamber 131; a first discharge electrode 134a disposed in an internal space of the chamber along an optical axis of the laser beam in a longitudinal direction; a second discharge electrode 134b disposed in the internal space opposite to the first discharge electrode and disposed along the optical axis of the laser beam in the longitudinal direction; a return member electrically connected to the chamber and electrically connected from one end side to the other end side in the longitudinal direction of the second discharge electrode; and a support member 400 that is fixed to the chamber and supports the second discharge electrode. The present invention provides the laser chamber apparatus in which the second discharge electrode and the chamber are not electrically connected to each other through the support member.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present disclosure relates to a laser chamber 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] Summary of JP-A-4-5877

[0005] A laser chamber apparatus according to one aspect of the present disclosure is a laser chamber apparatus that emits laser light, and includes a chamber body, a first discharge electrode that is arranged in the internal space of the chamber body with its longitudinal direction aligned with the optical axis of the laser light, a second discharge electrode that faces the first discharge electrode in the internal space and is arranged with its longitudinal direction aligned with the optical axis of the laser light, a return member that is electrically connected to the chamber body and electrically connected from one end side to the other end side of the second discharge electrode in the longitudinal direction, and a support member that is fixed to the chamber body and supports the second discharge electrode, and the second discharge electrode and the chamber body may be non-conductive via the support member.

[0006] A gas laser device according to one aspect of the present disclosure is a gas laser device including a laser chamber device that emits laser light, the laser chamber device including a chamber body, a first discharge electrode that is arranged in the internal space of the chamber body with its longitudinal direction aligned with the optical axis of the laser light, a second discharge electrode that faces the first discharge electrode in the internal space and is arranged with its longitudinal direction aligned with the optical axis of the laser light, a return member that is electrically connected to the chamber and electrically connected from one end side to the other end side of the second discharge electrode in the longitudinal direction, and a support member that is fixed to the chamber body and supports the second discharge electrode, and the second discharge electrode and the chamber body may be non-conductive via the support member.

[0007] A method for manufacturing an electronic device according to one aspect of the present disclosure includes a laser chamber apparatus that emits laser light, the laser chamber apparatus comprising: a chamber body; a first discharge electrode that is arranged in the internal space of the chamber body with its longitudinal direction aligned with the optical axis of the laser light; a second discharge electrode that faces the first discharge electrode in the internal space and is arranged with its longitudinal direction aligned with the optical axis of the laser light; a return member that is electrically connected to the chamber body and is electrically connected from one end side to the other end side of the second discharge electrode in the longitudinal direction; and a support member that is fixed to the chamber body and supports the second discharge electrode.The second discharge electrode and the chamber body are not electrically connected to each other via the support member.Laser light generated by the gas laser apparatus is output to an exposure apparatus via the support member, and the laser light may be exposed onto a photosensitive substrate in the exposure apparatus to manufacture an electronic device. [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 an explanatory diagram showing how the ground plate and the chamber body are positioned. [Figure 5] FIG. 5 is an explanatory diagram showing how the second discharge electrode and the ground plate are positioned. [Figure 6] FIG. 6 is a diagram showing the return member. [Figure 7] FIG. 7 is a cross-sectional view of a chamber apparatus of a comparative example taken along a plane parallel to the optical axis of the laser light. [Figure 8] FIG. 8 is a cross-sectional view of the chamber apparatus of the first embodiment taken along a plane parallel to the optical axis of the laser light. [Figure 9] FIG. 9 is a cross-sectional view of the chamber apparatus of the second embodiment taken along a plane parallel to the optical axis of the laser light. [Figure 10] FIG. 10 is a cross-sectional view of the chamber apparatus of the second embodiment taken along a plane perpendicular to the optical axis of the laser light. [Figure 11] FIG. 11 is an explanatory diagram showing how the second discharge electrode, the mounting member, and the support member are positioned. 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 5. Description of Embodiment 2 5.1 Configuration 5.2 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 emits 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] 2, gas laser device 100 mainly comprises a housing 110, a laser oscillator 130, a monitor module 160, a shutter 170, and a laser processor 190. In the following description, the left side of the drawing along the direction of travel of the laser light may be referred to as the front side, the right side of the drawing as the rear side, the upper side of the drawing as the upper side, and the lower side of the drawing as the lower side.

[0015] The laser oscillator 130 mainly comprises a laser chamber apparatus 101, a charger 141, a line narrowing module 145, an output coupling mirror 147, and a pulse compression circuit 150. In the following description, the laser chamber apparatus 101 may be simply referred to as the chamber apparatus 101. Figure 2 shows the internal configuration of the chamber apparatus 101 in a cross section taken along the optical axis of the laser light.

[0016] FIG. 3 is a cross-sectional view of the chamber apparatus 101 taken perpendicular to the optical axis of the laser light. The chamber apparatus 101 includes a discharge chamber 131. The discharge chamber 131 encloses an internal space in which light is generated by excitation of the laser medium in the laser gas by discharge, as described below. As shown in FIGS. 2 and 3, the discharge chamber 131 of the chamber apparatus 101 in this example includes a chamber body 131M and an electrically insulating plate 135 as a lid. The chamber body 131M is made of a conductive material, such as nickel-plated aluminum or nickel-plated stainless steel.

[0017] An opening 131H is provided in the top wall 131U of the chamber body 131M. The opening 131H is closed by an electrical insulating plate 135. Specifically, a metal seal 133 is disposed in a groove 132 formed in the upper surface of the chamber body 131M, and the metal seal 133 is pressed by the electrical insulating plate 135 so as to be crushed. Therefore, the space between the chamber body 131M and the electrical insulating plate 135 is sealed by the metal seal 133. In this way, the chamber body 131M and the electrical insulating plate 135 are combined with each other to enclose the internal space of the discharge chamber 131. The internal space is filled with laser gas.

[0018] The electrically insulating plate 135 includes an insulator. For example, the electrically insulating plate 135 may be made of aluminum oxide ceramics, which has low reactivity with F2 gas. The electrically insulating plate 135 may be made of any material as long as it has electrical insulation properties. Examples of materials for the electrically insulating plate 135 include resins such as phenolic resin and fluororesin, quartz, and glass.

[0019] In the internal space of the discharge chamber 131, the first discharge electrode 134a and the second discharge electrode 134b face each other at a distance from each other and are arranged with their respective longitudinal directions aligned along a predetermined direction that is the optical axis of the laser light. In this example, the first discharge electrode 134a is located directly above the second discharge electrode 134b. The first discharge electrode 134a and the second discharge electrode 134b are electrodes for exciting the laser medium by glow discharge. In this example, the first discharge electrode 134a is a cathode and the second discharge electrode 134b is an anode.

[0020] The ground plate 137 extends in the optical axis direction of the laser beam and is fixed to the inner walls on the rear and front sides of the chamber body 131M. The second discharge electrode 134b is disposed on the ground plate 137, and the ground plate 137 is a support member that supports the second discharge electrode 134b. In this example, the ground plate 137 is conductive and electrically connected to the second discharge electrode 134b.

[0021] Spacers 187 are fixed to both sides of the second discharge electrode 134b in a direction perpendicular to the longitudinal direction. The spacers 187 are made of a conductive material and are electrically connected to the ground plate 137 and the second discharge electrode 134b. An example of a material for the spacers 187 is porous nickel metal, which has low reactivity with laser gas.

[0022] A return member 300a is connected to one of the spacers 187 on the side opposite the second discharge electrode 134b, and a return member 300b is connected to the other of the spacers 187 on the side opposite the second discharge electrode 134b. The return members 300a and 300b are conductive members. The spacer 187 extends from one end of the second discharge electrode 134b in the longitudinal direction to the other end. The ends of the return members 300a and 300b on the second discharge electrode 134b side also extend along the longitudinal direction of the second discharge electrode 134b from one end to the other end of the second discharge electrode 134b in the longitudinal direction.

[0023] The second discharge electrode 134b and the spacer 187 are in contact along the longitudinal direction, and the spacer 187 and the return members 300a and 300b are in contact along the longitudinal direction. Therefore, the second discharge electrode 134b and the return members 300a and 300b are electrically connected from one end to the other end of the second discharge electrode 134b in the longitudinal direction. The end of the return member 300a opposite the second discharge electrode 134b side is connected to a side of the opening 131H in the ceiling wall 131U of the chamber body 131M. The end of the return member 300b opposite the second discharge electrode 134b side is connected to a side of the opening 131H in the ceiling wall 131U of the chamber body 131M opposite the side to which the return member 300a is connected. Therefore, the return members 300a and 300b electrically connect the second discharge electrode 134b and the chamber body 131M.

[0024] The chamber body 131M is electrically connected to ground. Therefore, the second discharge electrode 134b is electrically connected to ground via the spacer 187, the ground plate 137, the return members 300a and 300b, and the chamber body 131M. The spacer 187 may be omitted, and the second discharge electrode 134b side and the return member 300a, and the second discharge electrode 134b side and the return member 300b may be directly connected, respectively. The return members 300a and 300b are preferably made of a material that does not easily react chemically with the laser gas. Examples of such conductive materials include copper and nickel.

[0025] The first discharge electrode 134a is airtightly fixed to the surface of the electrically insulating plate 135 facing the internal space of the discharge chamber 131 by a current introducing terminal 157, which may be a bolt, for example. Therefore, the first discharge electrode 134a is insulated from the chamber main body 131M. The current introducing terminal 157 is electrically connected to the pulse compression circuit 150 and other circuit components, ensuring electrical continuity between the pulse compression circuit 150 and the first discharge electrode 134a.

[0026] Charger 141 is a DC high-voltage power supply that supplies electrical energy to pulse compression circuit 150. Switch 151 is electrically connected to charger 141 and controlled by laser processor 190. When switch 151 is turned from OFF to ON, electrical energy from charger 141 is supplied to pulse compression circuit 150. Pulse compression circuit 150 generates a pulsed high voltage from the electrical energy held in charger 141 and applies this high voltage to first discharge electrode 134a.

[0027] When a high voltage is applied to first discharge electrode 134a, a discharge occurs between first discharge electrode 134a and second discharge electrode 134b due to the potential difference between first discharge electrode 134a and second discharge electrode 134b. The energy of this discharge excites the laser medium in discharge chamber 131, and the excited laser medium emits light when it transitions to the ground state.

[0028] A preionization electrode 180 is provided on one side of the second discharge electrode 134b on the ground plate 137, via a spacer 187 and an end of a return member 300a. The preionization electrode 180 includes a dielectric pipe 181, an inner preionization electrode 183, and an outer preionization electrode 185.

[0029] The dielectric pipe 181 is, for example, a cylindrical pipe, and its longitudinal direction is arranged along the longitudinal direction of the second discharge electrode 134b. The dielectric pipe 181 is made of, for example, aluminum oxide ceramics or sapphire. The preionization inner electrode 183 is rod-shaped and is arranged inside the dielectric pipe 181, extending along the longitudinal direction of the dielectric pipe 181. The preionization inner electrode 183 is made of, for example, copper or brass. The preionization outer electrode 185 is arranged between the dielectric pipe 181 and the second discharge electrode 134b, extends along the longitudinal direction of the dielectric pipe 181, and is fixed to a spacer 187. If the spacer 187 is omitted, the preionization outer electrode 185 is fixed to the second discharge electrode 134b. The end of the preionization outer electrode 185 is in contact with the outer peripheral surface of the dielectric pipe 181. It should be noted that a part of the end of the preionization outer electrode 185 does not need to be in contact with the outer circumferential surface of the dielectric pipe 181 as long as a corona discharge, which will be described later, occurs.

[0030] The preionization inner electrode 183 is electrically connected to the pulse compression circuit 150 via a preionization capacitor (not shown). The preionization outer electrode 185 is electrically connected to the second discharge electrode 134b via the ground plate 137, and is also electrically connected to the chamber body 131M via the ground plate 137 and the return members 300a and 300b. Therefore, the preionization outer electrode 185 is electrically connected to ground. When a high voltage is applied between the preionization inner electrode 183 and the preionization outer electrode 185 from the pulse compression circuit 150, a corona discharge is generated near the end of the preionization outer electrode 185. This corona discharge assists in the stable generation of a glow discharge between the first discharge electrode 134a and the second discharge electrode 134b.

[0031] FIG. 4 is an explanatory diagram showing the positioning of the ground plate 137 and the chamber body 131M. While the following describes the fixation of the ground plate 137 to the rear inner wall of the chamber body 131M, the fixation of the ground plate 137 to the front inner wall of the chamber body 131M is similar. The chamber body 131M can be divided into an upper portion 131Ma and a lower portion 131Mb, and the space between the upper portion 131Ma and the lower portion 131Mb is sealed with an O-ring 131Mo. A recess 137H recessed downward is provided on the periphery of the upper surface 137U of the ground plate 137. A protrusion 131MT protruding into the internal space is provided on the inner wall of the upper portion 131Ma, and a recess 131MH recessed upward is provided on the lower surface 131MS of the protrusion 131MT at a position opposite the recess 137H. Positioning pins 138A are inserted into recesses 137H of the ground plate 137 and recesses 131MH of the chamber body 131M, restricting horizontal movement of the ground plate 137. Furthermore, the lower surfaces 131MS of the protrusions 131MT come into contact with the upper surface 137U of the ground plate 137, restricting vertical movement of the ground plate 137, and the ground plate 137 is fixed to the chamber body 131M with bolts or the like (not shown). In this way, the ground plate 137 is positioned relative to the inner wall of the chamber body 131M.

[0032] FIG. 5 is an explanatory diagram showing the positioning of the second discharge electrode 134b and the ground plate 137. An upwardly recessed recess 134bH is provided on the lower surface 134bS of the second discharge electrode 134b. Furthermore, a downwardly recessed recess 137H2 is provided on the upper surface 137U of the ground plate 137 at a position opposite the recess 134bH. Positioning pins 138B are inserted into the recess 134bH of the second discharge electrode 134b and the recess 137H2 of the ground plate 137, restricting horizontal movement of the second discharge electrode 134b. Furthermore, the upper surface 137U of the ground plate 137 abuts against the lower surface 134bS of the second discharge electrode 134b, restricting vertical movement of the second discharge electrode 134b, and the second discharge electrode 134b is fixed to the ground plate 137 with bolts or the like (not shown). In this way, the second discharge electrode 134b is positioned relative to the ground plate 137. In this manner, the second discharge electrode 134b is positioned relative to the chamber body 131M via the ground plate 137.

[0033] 3, stabilizer 138a is provided on the side of ground plate 137 on which return member 300a is provided. Also, guide 138b is provided on the underside of ground plate 137 on which return member 300b is provided. Stabilizer 138a and guide 138b are members that rectify the flow of laser gas so that the flow of laser gas is directed in the appropriate direction.

[0034] A cross-flow fan 149 and a heat exchanger 148 are disposed in the internal space of the discharge chamber 131 on the side opposite the second discharge electrode 134b with respect to the ground plate 137. The space in the discharge chamber 131 in which the cross-flow fan 149 and heat exchanger 148 are disposed communicates with the space between the first discharge electrode 134a and the second discharge electrode 134b. The heat exchanger 148 is a radiator disposed beside the cross-flow fan 149 and connected to piping (not shown) through which a cooling medium flows. As shown in FIG. 2, the cross-flow fan 149 is connected to a motor 149a disposed outside the discharge chamber 131 and rotates as the motor 149a rotates. As the cross-flow fan 149 rotates, the laser gas filling the internal space of the discharge chamber 131 circulates as shown by the arrows in FIG. 3. That is, crossflow fan 149 causes laser gas to flow in a direction roughly perpendicular to the optical axis of the laser light between first discharge electrode 134a and second discharge electrode 134b. By causing laser gas to flow in this manner, return member 300a is located on the upstream side of the laser gas, and return member 300b is located on the downstream side of the laser gas. At least a portion of the circulating laser gas passes through heat exchanger 148, and the temperature of the laser gas is adjusted.

[0035] The laser gas is supplied from a laser gas supply source (not shown) through piping (not shown). The laser gas in discharge chamber 131 is subjected to treatment such as removal of F gas using a halogen filter, and is then exhausted into housing 110 through piping (not shown) by an exhaust pump (not shown).

[0036] A pair of windows 139a and 139b are provided on the wall surface of the discharge chamber 131. Window 139a is located at one end of the discharge chamber 131 in the direction in which the laser light travels, and window 139b is located at the other end in the same direction. The windows 139a and 139b sandwich a space between the first discharge electrode 134a and the second discharge electrode 134b. The windows 139a and 139b may be inclined at a Brewster angle with respect to the direction in which the laser light travels, so as to suppress reflection of the laser light. As described below, the oscillated laser light is emitted to the outside of the discharge chamber 131 via the windows 139a and 139b. As described above, a pulsed high voltage is applied between the first discharge electrode 134a and the second discharge electrode 134b by the pulse compression circuit 150, and therefore the laser light is pulsed laser light.

[0037] The line narrowing module 145 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 discharge chamber 131 via the opening.

[0038] 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 discharge chamber 131 via window 139a. Prism 145b is supported on a rotation stage (not shown) and rotates by the rotation stage. Rotation of prism 145b changes the angle of incidence of the light with respect to grating 145c, making it possible to select the wavelength of light returning from grating 145c to discharge chamber 131 via prism 145b. While FIG. 2 shows an example in which one prism 145b is provided, it is sufficient that at least one prism is provided.

[0039] The surface of 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 enters grating 145c from prism 145b, it is diffracted in a direction corresponding to its wavelength when reflected by these grooves. Grating 145c is Littrow-oriented so that the angle of incidence of light entering grating 145c from prism 145b matches the angle of diffraction of diffracted light of the desired wavelength. This allows light near the desired wavelength to be returned to discharge chamber 131 via prism 145b.

[0040] Output coupling mirror 147 is disposed in the internal space of optical path tube 147a connected to the front side of discharge chamber 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 discharge chamber 131 via window 139b. In this way, grating 145c and output coupling mirror 147 form a Fabry-Perot type laser resonator.

[0041] 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.

[0042] 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 outputs a signal indicating the energy E of the laser light incident on the light receiving surface to laser processor 190.

[0043] 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.

[0044] 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 (described later) and a target energy Et 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 received from the optical sensor 165 and the target energy Et received from the exposure processor 230. The energy of the laser light is controlled by controlling the charging voltage. The laser processor 190 is also electrically connected to the shutter 170 and controls the opening and closing of the shutter 170.

[0045] The shutter 170 is disposed on the optical path of 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 600 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.

[0046] Next, the configuration of the return members 300a and 300b will be described.

[0047] In this example, since the return members 300a and 300b have the same configuration, only the return member 300a will be described. Fig. 6 is a diagram showing the return member 300a. As shown in Fig. 6, the return member 300a is formed, for example, by stamping and bending a single metal plate, and includes a plate-shaped first fixed portion 311, a plate-shaped second fixed portion 312, and a ladder portion 320 connected to the first fixed portion 311 and the second fixed portion 312. The thickness of the metal plate that is stamped and bent is, for example, 1.0 mm to 1.2 mm.

[0048] The first fixed part 311 is a member whose main surface is roughly rectangular, and is attached to the ceiling wall 131U of the chamber body 131M with its longitudinal direction aligned with the longitudinal direction of the first discharge electrode 134a. The main surface of the first fixed part 311 is the plane specified by the end point of the lead line extending from reference numeral 311 in Fig. 6. The second fixed part 312 has roughly the same shape as the first fixed part 311, and is attached to the spacer 187 with its longitudinal direction aligned with the longitudinal direction of the second discharge electrode 134b.

[0049] The ladder portion 320 is formed by a plurality of linear portions 321 arranged in parallel. The width of each linear portion 321 is, for example, approximately 1.0 mm. One end of each linear portion 321 is connected to the first fixing portion 311, and the other end is connected to the second fixing portion 312. As described above, in this example, the return member 300a is formed by stamping a single metal plate, and this connection is not by welding or brazing, but is in a continuous metal state. By connecting each linear portion 321 to the first fixing portion 311 and the second fixing portion 312, the plurality of linear portions 321 are arranged in parallel along the longitudinal direction of the first discharge electrode 134a and the second discharge electrode 134b, which is along the optical axis of the laser light. The width of the gap between adjacent linear portions 321 is, for example, 19.0 mm to 19.5 mm, and as shown in FIG. 3, laser gas can pass through this gap.

[0050] The connection portions or vicinity of the connection portions between first fixed portion 311 and each linear portion 321 are bent, and the parallel direction of each linear portion 321 is non-parallel to the main surface of first fixed portion 311. Furthermore, the connection portions or vicinity of the connection portions between second fixed portion 312 and each linear portion 321 are bent, and the parallel direction of each linear portion 321 is non-parallel to the main surface of second fixed portion 312. Furthermore, the main surface of first fixed portion 311 and the main surface of second fixed portion 312 are non-parallel to each other, for example, forming an angle of approximately 90 degrees.

[0051] 2.2 Operation Next, the operation of the gas laser device 100 of the comparative example will be described.

[0052] Before gas laser device 100 emits laser light, the internal spaces of optical path pipes 147a, 171, and 600 and 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 discharge chamber 131 from a laser gas supply source (not shown). When laser gas is supplied, laser processor 190 controls motor 149a to rotate crossflow fan 149. The rotation of crossflow fan 149 circulates the laser gas within the internal space of discharge chamber 131. At this time, the gap between chamber body 131M and electrical insulating plate 135 is sealed by metal seal 133, preventing the laser gas from leaking outside discharge chamber 131.

[0053] The laser gas is circulated by crossflow fan 149 as shown by the arrows in Figure 3. At this time, the laser gas passes between linear portions 321 of return member 300a, which is provided upstream of first discharge electrode 134a and second discharge electrode 134b in the direction of the laser gas flow. The laser gas then passes between first discharge electrode 134a and second discharge electrode 134b, and passes between linear portions 321 of return member 300b, which is provided downstream of first discharge electrode 134a and second discharge electrode 134b in the direction of the laser gas flow.

[0054] When 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 gas laser device 100 is controlled to emit laser light. Upon receiving the signal indicating the target energy Et, the laser processor 190 closes the shutter 170 and drives the charger 141. The laser processor 190 also turns on the switch 151 of the pulse compression circuit 150. This causes current from the charger 141 to flow through the pulse compression circuit 150, and a pulsed high voltage is applied to the first discharge electrode 134a via the current introduction terminal 157. The timing at which the high voltage is applied between the preionization inner electrode 183 and the preionization outer electrode 185 is slightly earlier than the timing at which the high voltage is applied between the first discharge electrode 134a and the second discharge electrode 134b. When a high voltage is applied between the preionization inner electrode 183 and the preionization outer electrode 185, a corona discharge occurs near the ends of the dielectric pipe 181 and the preionization outer electrode 185, and ultraviolet light is emitted. When ultraviolet light is irradiated onto the laser gas between the first discharge electrode 134a and the second discharge electrode 134b, the laser gas between the first discharge electrode 134a and the second discharge electrode 134b is preionized. After preionization, when a high voltage is applied between the first discharge electrode 134a and the second discharge electrode 134b as described above, a main discharge occurs between the first discharge electrode 134a and the second discharge electrode 134b. Because the return members 300a and 300b are connected to the chamber body 131M, a current of the main discharge flows to the chamber body 131M via the return members 300a and 300b.

[0055] This main discharge excites the laser medium contained in the laser gas between first discharge electrode 134a and second discharge electrode 134b, and it emits light when it returns to its ground state. This light resonates between grating 145c and output coupling mirror 147, and is amplified each time it passes through the discharge space between first discharge electrode 134a and second discharge electrode 134b in the internal space of discharge chamber 131, resulting in laser oscillation. A portion of the resonating laser light passes through output coupling mirror 147 as pulsed laser light and proceeds to beam splitter 163.

[0056] A portion of the laser light that has traveled to the beam splitter 163 is reflected by the beam splitter 163 and received by the optical sensor 165. The optical sensor 165 measures the energy E of the received laser light and outputs a signal indicating the energy E to the laser processor 190. The 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, and after the difference ΔE falls within the allowable range, it sends a reception preparation completion signal to the exposure processor 230 indicating that preparation for receiving the light emission trigger Tr has been completed.

[0057] When the exposure processor 230 receives the ready-to-receive signal, it transmits a light emission trigger Tr to the laser processor 190. When the laser processor 190 opens the shutter 170 in synchronization with the reception of the light emission trigger Tr, the laser light that has passed through the shutter 170 enters the exposure device 200. This laser light is, for example, a pulsed laser light with a center wavelength of 193 nm.

[0058] 3. Challenges FIG. 7 is a cross-sectional view of a chamber apparatus 101 of a comparative example, taken along a plane parallel to the optical axis of the laser beam. One factor determining the service life of the chamber apparatus 101 is wear of the first discharge electrode 134a. The inventors discovered through experiments that the current flowing from the second discharge electrode 134b to the chamber body M through the linear portions 321 near both longitudinal ends of the return members 300a and 300b may be smaller than the current flowing near the longitudinal center of the return members 300a and 300b. If the distribution of the return current flowing through the return members 300a and 300b is uneven in the longitudinal direction, it can be assumed that the main discharge is also uneven along the longitudinal direction of the first discharge electrode 134a and the second discharge electrode 134b. If the main discharge is uneven, the first discharge electrode 134a is likely to wear unevenly, potentially shortening the service life of the first discharge electrode 134a due to the portions that wear out quickly.

[0059] This is thought to be due to the current that should flow through the linear portions 321 near both longitudinal ends of the return members 300a and 300b instead flowing through the fixed portions between the ground plate 137 and the inner wall of the chamber body 131M. Therefore, it is predicted that the uniformity of the main discharge can be improved by reducing the current that flows through the fixed portions between the ground plate 137 and the inner wall of the chamber body 131M. This is thought to extend the life of the first discharge electrode 134a and the chamber apparatus 101. Therefore, the following embodiments illustrate a laser chamber apparatus 101 and a gas laser apparatus 100 that can achieve a long life.

[0060] 4. Description of Embodiment 1 Next, the chamber apparatus 101 of embodiment 1 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. 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.

[0061] 4.1 Configuration FIG. 8 is a view similar to FIG. 7 showing the chamber apparatus 101 of this embodiment. The chamber apparatus 101 of this embodiment differs from the comparative example in that it includes a support member 400, which is an insulator, instead of the ground plate 137. Therefore, in the chamber apparatus 101, the second discharge electrode 134b and the chamber body 131M are not electrically connected via the support member 400. The shape of the support member 400 is the same as that of the ground plate 137 of the comparative example. Therefore, the support member 400 is fixed to the chamber body 131M in the same manner as the ground plate 137 of the comparative example. The material of the support member 400 is ceramics or the like, and may be, for example, aluminum oxide ceramics.

[0062] 4.2 Actions and Effects In the chamber apparatus 101 of this embodiment, no current flows from the second discharge electrode 134b to the support member 400. Therefore, the longitudinal uniformity of the return current flowing through the return members 300a, 300b can be improved. The improved longitudinal uniformity of the return current can improve the longitudinal uniformity of the discharge between the first discharge electrode 134a and the second discharge electrode 134b. Therefore, uneven wear of the first discharge electrode 134a is suppressed, and the life of the gas laser apparatus 100 can be extended. Furthermore, since the shape of the support member 400 is the same as that of the ground plate 137 of the comparative example, the positioning structure of the second discharge electrode 134b can be maintained.

[0063] The return members 300a, 300b and the spacer 187 are preferably provided from one end to the other end in the longitudinal direction of the second discharge electrode 134b, but are not limited to this. The return members 300a, 300b and the spacer 187 may be positioned slightly outward from both ends of the second discharge electrode 134b in the longitudinal direction, or slightly inward from both ends.

[0064] 5. Description of Embodiment 2 A chamber apparatus 101 according to a second embodiment will now be described. The same components as those described above are designated by the same reference numerals, and redundant descriptions will be omitted unless otherwise specified. Furthermore, in some drawings, for clarity, some components may be omitted or simplified, and similar components may be designated by only some reference numerals, with some reference numerals omitted.

[0065] 5.1 Configuration Fig. 9 is a view similar to Fig. 7 showing the chamber apparatus 101 of this embodiment. Fig. 10 is a cross-sectional view perpendicular to the optical axis of the laser light in the chamber apparatus 101 of this embodiment. Fig. 11 is an explanatory view showing how the mounting member 500 and the support member 400 are positioned, and how the second discharge electrode 134b and the mounting member 500 are positioned.

[0066] As shown in FIG. 9 , the support member 400 of this embodiment differs from the first embodiment mainly in that the second discharge electrode 134b is supported via a mounting member 500 made of an insulator. The mounting member 500 of this embodiment is made of ceramics or the like, such as aluminum oxide ceramics. The thickness of the mounting member 500 in the Y direction is preferably 1.5 mm or more. The support member 400 of this embodiment may be made of an insulator or may be conductive. The support member 400 may be made of a metal such as aluminum. Furthermore, to make the distance between the first discharge electrode 134a and the second discharge electrode 134b the same as in the comparative example, the thickness of the second discharge electrode 134b in the Y axis direction may be reduced by the thickness of the mounting member 500.

[0067] As shown in FIG. 10, in this embodiment, the return members 300a and 300b are not in contact with the support member 400.

[0068] In this embodiment, the second discharge electrode 134b is positioned relative to the mounting member 500. As shown in FIG. 11 , a recess 400H recessed downward is provided in the upper surface 400U of the support member 400. A recess 500H2 recessed upward is provided in the lower surface 500S of the mounting member 500 at a position opposite the recess 400H. Positioning pins 138D are inserted into the recess 400H of the support member 400 and the recess 500H2 of the mounting member 500, thereby restricting horizontal movement of the mounting member 500. Furthermore, vertical movement of the mounting member 500 is restricted by the lower surface 500S of the mounting member 500 abutting against the upper surface 400U of the support member 400, and the mounting member 500 is fixed to the support member 400 with bolts or the like (not shown). In this way, the mounting member 500 is positioned relative to the support member 400.

[0069] A recess 500H recessed downward is provided on the upper surface 500U of the mounting member 500. A recess 134bH recessed upward is provided on the lower surface 134bS of the second discharge electrode 134b at a position facing the recess 500H. Positioning pins 138C are inserted into the recess 500H of the mounting member 500 and the recess 134bH of the second discharge electrode 134b, thereby restricting horizontal movement of the second discharge electrode 134b. Furthermore, the lower surface 134bS of the second discharge electrode 134b abuts against the upper surface 500U of the mounting member 500, thereby restricting vertical movement of the second discharge electrode 134b, and the second discharge electrode 134b is fixed to the mounting member 500 with bolts or the like (not shown). In this way, the second discharge electrode 134b is positioned with respect to the mounting member 500.

[0070] 5.2 Actions and Effects In the chamber apparatus 101 according to this embodiment, the mounting member 500 is made of an insulator. Therefore, current can mainly flow to ground through the return members 300a and 300b, and the longitudinal uniformity of the return current flowing through the return members 300a and 300b can be improved. The improved longitudinal uniformity of the return current can improve the longitudinal uniformity of the discharge between the first discharge electrode 134a and the second discharge electrode 134b. This can suppress uneven wear of the first discharge electrode 134a, thereby extending the life of the gas laser apparatus 100. Furthermore, the mounting member 500 can be realized with a shape that is smaller than the support member 400 and easier to machine. This facilitates positioning of the second discharge electrode 134b, and because the support member 400 can be manufactured from an inexpensive metal material such as aluminum, costs can be reduced.

[0071] The above description is intended to be illustrative, not limiting. Accordingly, it will be apparent to one skilled in the art that modifications can be made to the embodiments of the present disclosure without departing from the scope of the claims. It will also be apparent to one skilled in the art that the embodiments of the present disclosure can be used in combination. Terms used throughout this specification and claims should be construed as "open-ended" terms unless expressly stated. For example, terms such as "comprise," "have," "comprise," and "equip" should be interpreted as meaning "without excluding the presence of elements other than those listed." The modifier "a" or "an" should be interpreted as meaning "at least one" or "one or more." The term "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," including combinations other than "A," "B," and "C."

Claims

1. A laser chamber device that emits laser light, a chamber body; a first discharge electrode disposed in the internal space of the chamber body, the first discharge electrode having a longitudinal direction aligned with the optical axis of the laser light; a second discharge electrode disposed in the internal space, facing the first discharge electrode, and having a longitudinal direction aligned with the optical axis of the laser light; a return member electrically connected to the chamber body and electrically connected from one end side to the other end side of the second discharge electrode in the longitudinal direction; a support member fixed to the chamber body and supporting the second discharge electrode; Equipped with The second discharge electrode and the chamber body are not electrically connected via the support member.

2. 2. The laser chamber apparatus according to claim 1, The support member is made of an insulating material.

3. 2. The laser chamber apparatus according to claim 1, The support member supports the second discharge electrode via a mounting member made of an insulating material.

4. 2. The laser chamber apparatus according to claim 1, The first discharge electrode is a cathode, and the second discharge electrode is an anode.

5. 2. The laser chamber apparatus according to claim 1, The return member includes a plurality of linear portions arranged in parallel along the longitudinal direction of the second discharge electrode.

6. 2. The laser chamber apparatus according to claim 1, The support member is positioned in the chamber body by a positioning pin.

7. 4. The laser chamber apparatus according to claim 3, The mounting member has a thickness of 1.5 mm or more.

8. A gas laser device including a laser chamber device that emits laser light, The laser chamber device includes: a chamber body; a first discharge electrode disposed in the internal space of the chamber body, the first discharge electrode having a longitudinal direction aligned with the optical axis of the laser light; a second discharge electrode disposed in the internal space, facing the first discharge electrode, and having a longitudinal direction aligned with the optical axis of the laser light; a return member electrically connected to the chamber body and electrically connected from one end side to the other end side of the second discharge electrode in the longitudinal direction; a support member fixed to the chamber body and supporting the second discharge electrode; Equipped with The second discharge electrode and the chamber body are not electrically connected via the support member.

9. A method for manufacturing an electronic device, comprising: A gas laser device including a laser chamber device that emits laser light, a laser chamber device that emits the laser light, a chamber body; a first discharge electrode disposed in the internal space of the chamber body, the first discharge electrode having a longitudinal direction aligned with the optical axis of the laser light; a second discharge electrode disposed in the internal space, facing the first discharge electrode, and having a longitudinal direction aligned with the optical axis of the laser light; a return member electrically connected to the chamber body and electrically connected from one end side to the other end side of the second discharge electrode in the longitudinal direction; a support member fixed to the chamber body and supporting the second discharge electrode; Equipped with the second discharge electrode and the chamber body are not electrically connected to each other via the support member; and the laser light generated by the gas laser device is output to an exposure device. exposing the laser light onto a photosensitive substrate in the exposure apparatus to manufacture an electronic device. A method for manufacturing an electronic device, comprising:

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