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

Abstract

The invention provides a laser chamber apparatus, a gas laser apparatus, and a method for manufacturing an electronic device. The chamber device for laser light emits laser light, and comprises: a chamber main body; a first discharge electrode disposed in the internal space of the chamber main body so that the longitudinal direction thereof is along the optical axis of the laser light; a second discharge electrode disposed in the internal space so as to face the first discharge electrode in such a manner that the longitudinal direction thereof is along the optical axis of the laser light; a return member electrically connected to the chamber main body and electrically connected to the second discharge electrode in a range from one end side to the other end side in the longitudinal direction of the second discharge electrode; and a support member that is fixed to the chamber main body and supports the second discharge electrode, the second discharge electrode and the chamber main body being non-conductive via the support member.

Description

Technical Field

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

[0002] In recent years, semiconductor exposure equipment has been required to achieve higher resolution as semiconductor integrated circuits become increasingly miniaturized and highly integrated. Consequently, there has been a trend toward shorter wavelengths of light emitted from exposure light sources. For example, gas laser devices used for exposure include KrF excimer lasers, which output laser light with a wavelength of approximately 248 nm, and ArF excimer lasers, which output laser light with a wavelength of approximately 193 nm.

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

[0004] Prior art literature

[0005] Patent Literature

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 4-5877 Summary of the Invention

[0007] A laser chamber device according to one embodiment of the present disclosure may be a laser chamber device for emitting laser light, comprising: a chamber body; a first discharge electrode disposed within an internal space of the chamber body with its longitudinal direction aligned with an optical axis of the laser light; a second discharge electrode disposed within the internal space with its longitudinal direction aligned with the optical axis of the laser light, facing the first discharge electrode; a return member electrically connected to the chamber body and electrically connected to the second discharge electrode over a range from one end to the other end of the second discharge electrode in its longitudinal direction; and a support member fixed to the chamber body and supporting the second discharge electrode, with no electrical continuity between the second discharge electrode and the chamber body via the support member.

[0008] A gas laser device according to one embodiment of the present disclosure may be a gas laser device including a laser chamber device for emitting laser light. The laser chamber device includes: a chamber body; a first discharge electrode disposed within an internal space of the chamber body with its longitudinal direction aligned with an optical axis of the laser light; a second discharge electrode disposed within the internal space with its longitudinal direction aligned with the optical axis of the laser light, facing the first discharge electrode; a return member electrically connected to the chamber body and electrically connected to the second discharge electrode over a range from one end to the other end of the second discharge electrode in its longitudinal direction; and a support member fixed to the chamber body and supporting the second discharge electrode, wherein the second discharge electrode and the chamber body are not electrically connected via the support member.

[0009] A method for manufacturing an electronic device according to one embodiment of the present disclosure may include the following steps: outputting laser light generated by a gas laser device to an exposure device; and exposing the laser light to a photosensitive substrate in the exposure device to manufacture the electronic device, wherein the gas laser device includes a laser chamber device for emitting the laser light, the laser chamber device for emitting the laser light including: a chamber body; a first discharge electrode disposed within an interior space of the chamber body with its longitudinal direction along an optical axis of the laser light; a second discharge electrode disposed within the interior space with its longitudinal direction along the optical axis of the laser light, facing the first discharge electrode; a return member electrically connected to the chamber body and electrically connected to the second discharge electrode in a range from one end side to the other end side in the longitudinal direction of the second discharge electrode; and a support member fixed to the chamber body and supporting the second discharge electrode, wherein the second discharge electrode and the chamber body are not electrically connected via the support member. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Hereinafter, several embodiments of the present disclosure will be described with reference to the accompanying drawings, merely as examples.

[0011] Figure 1 This is a schematic diagram showing an example of the overall schematic configuration of an electronic device manufacturing apparatus.

[0012] Figure 2 It is a schematic diagram showing an overall schematic configuration example of a gas laser device according to a comparative example.

[0013] Figure 3 It is a cross-sectional view perpendicular to the optical axis of the laser light of a chamber device of a comparative example.

[0014] Figure 4 It is an explanatory diagram showing the positioning of the ground plate and the chamber body.

[0015] Figure 5 It is an explanatory diagram showing the positioning of the second discharge electrode and the ground plate.

[0016] Figure 6This is a diagram showing a return component.

[0017] Figure 7 This is a cross-sectional view of a chamber device according to a comparative example, taken along a plane parallel to the optical axis of the laser beam.

[0018] Figure 8 This is a cross-sectional view of the chamber device according to the first embodiment, taken along a plane parallel to the optical axis of the laser beam.

[0019] Figure 9 This is a cross-sectional view of the chamber device according to the second embodiment, taken along a plane parallel to the optical axis of the laser beam.

[0020] Figure 10 This is a cross-sectional view of the chamber device according to the second embodiment, taken perpendicularly to the optical axis of the laser beam.

[0021] Figure 11 It is an explanatory diagram showing the positioning of the second discharge electrode, the placement member, and the support member. DETAILED DESCRIPTION

[0022] 1. Description of the electronic device manufacturing apparatus used in the exposure process of the electronic device

[0023] 2. Description of Comparative Examples

[0024] 2.1 Structure

[0025] 2.2 Action

[0026] 3.Topic

[0027] 4. Description of Implementation Method 1

[0028] 4.1 Structure

[0029] 4.2 Function and effect

[0030] 5. Description of Implementation Method 2

[0031] 5.1 Structure

[0032] 5.2 Function and effect

[0033] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The embodiments described below represent several examples of the present disclosure and do not limit the content of the present disclosure. In addition, not all of the structures and actions described in each embodiment are necessarily required as the structures and actions of the present disclosure. In addition, the same reference numerals are attached to the same components, and repeated descriptions are omitted.

[0034] 1. Description of the electronic device manufacturing apparatus used in the exposure process of the electronic device

[0035] Figure 1Schematic diagram showing an overall schematic configuration example of an electronic device manufacturing apparatus used in an exposure process of an electronic device. Figure 1 As shown, the manufacturing apparatus used in the exposure process includes a gas laser device 100 and an exposure device 200. The exposure device 200 includes an illumination optical system 210 and a projection optical system 220, wherein the illumination optical system 210 has a plurality of mirrors 211, 212, and 213. The illumination optical system 210 illuminates the mask pattern on the mask carrier RT using the laser light incident from the gas laser device 100. The projection optical system 220 performs a reduced projection of the laser light transmitted through the mask so as to form an image on a workpiece (not shown) arranged on the workpiece stage WT. The workpiece is a photosensitive substrate such as a semiconductor wafer coated with a photoresist. The exposure device 200 exposes the workpiece with the laser light reflecting the mask pattern by moving the mask carrier RT and the workpiece stage WT in parallel in synchronization. By transferring the device pattern to the semiconductor wafer using the above-mentioned exposure process, a semiconductor device as an electronic device can be manufactured.

[0036] 2. Description of Comparative Examples

[0037] 2.1 Structure

[0038] A comparative example gas laser device 100 will be described. Note that the comparative examples disclosed herein are methods that the applicant has recognized as being known only to the applicant, and are not examples that the applicant considers to be publicly known.

[0039] Figure 2 : This is a schematic diagram showing an overall schematic configuration example of a gas laser device 100 of a comparative example. The gas laser device 100 is, for example, an ArF excimer laser device using a mixed gas containing argon (Ar), fluorine (F2), and neon (Ne). The gas laser device 100 emits laser light having a central wavelength of approximately 193 nm. Furthermore, the gas laser device 100 may be a gas laser device other than the ArF excimer laser device, for example, a KrF excimer laser device using a mixed gas containing krypton (Kr), F2, and Ne. In this case, the gas laser device 100 emits laser light having a central wavelength of approximately 248 nm. A mixed gas containing Ar, F2, and Ne as a laser medium, or a mixed gas containing Kr, F2, and Ne as a laser medium is sometimes referred to as a laser gas.

[0040] like Figure 2 As shown, the gas laser device 100 includes a housing 110, a laser oscillator 130, a monitoring module 160, an aperture 170, and a laser processor 190 as its main components. In the following description, the left side of the paper along the direction of laser travel is sometimes referred to as the front side, the right side of the paper as the rear side, the upper side of the paper as the top side, and the lower side of the paper as the bottom side.

[0041] The laser oscillator 130 mainly includes a laser cavity device 101, a charger 141, a narrowband module 145, an output coupling mirror 147, and a pulse compression circuit 150. In the following description, the laser cavity device 101 is sometimes referred to as the cavity device 101. Figure 2 , the internal structure of the chamber device 101 in a cross section along the optical axis of the laser light is shown.

[0042] Figure 3 1 is a cross-sectional view of the chamber device 101 perpendicular to the optical axis of the laser. The chamber device 101 includes a discharge chamber 131. The discharge chamber 131 surrounds an internal space in which light is generated by excitation of the laser medium in the laser gas by discharge described later. Figure 2 、 Figure 3 As shown, the discharge chamber 131 of the chamber apparatus 101 of this embodiment includes a chamber body 131M and an electrical insulating plate 135 as a cover. The chamber body 131M is made of a conductive material such as nickel-plated aluminum or nickel-plated stainless steel.

[0043] An opening 131H is provided in the top wall 131U of the chamber body 131M. This opening 131H is sealed by an electrically insulating plate 135. Specifically, a metal seal 133 is placed within a groove 132 formed on the upper surface of the chamber body 131M. The electrically insulating plate 135 presses against the metal seal 133, thereby flattening the metal seal 133. Thus, the metal seal 133 seals the space between the chamber body 131M and the electrically insulating plate 135. Thus, the chamber body 131M and the electrically insulating plate 135, when combined, enclose the interior space of the discharge chamber 131. This interior space is filled with laser gas.

[0044] The electrical insulating plate 135 is made of an insulator. Examples of materials for the electrical insulating plate 135 include ceramics made of aluminum oxide, which has low reactivity with F₂ gas. Furthermore, the electrical insulating plate 135 only needs to have electrical insulating properties. Examples of materials for the electrical insulating plate 135 include resins such as phenolic resin and fluororesin, as well as quartz and glass.

[0045] Within the interior of the discharge chamber 131, a first discharge electrode 134a and a second discharge electrode 134b are spaced apart and face each other, with their respective longitudinal directions aligned with a predetermined direction serving as 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 and second discharge electrodes 134a and 134b are electrodes used to excite the laser medium through glow discharge. In this example, the first discharge electrode 134a serves as the cathode, and the second discharge electrode 134b serves as the anode.

[0046] Ground plates 137 extend along the optical axis of the laser beam and are fixed to the rear and front inner walls of the chamber body 131M. Second discharge electrode 134b is disposed on ground plates 137, which serve as a support member for second discharge electrode 134b. In this example, ground plates 137 are conductive and electrically connected to second discharge electrode 134b.

[0047] Spacers 187 are fixed to both sides of the second discharge electrode 134b in a direction perpendicular to its 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. Examples of materials for the spacers 187 include porous nickel metal, which has low reactivity with laser gas.

[0048] A return member 300a is connected to the side of one spacer 187 opposite the second discharge electrode 134b, and a return member 300b is connected to the side of the other spacer 187 opposite the second discharge electrode 134b. The return members 300a and 300b are conductive members. The spacer 187 extends from one end to the other end in the longitudinal direction of the second discharge electrode 134b. Furthermore, 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.

[0049] The second discharge electrode 134b is in contact with the spacer 187 along the longitudinal direction, and the spacer 187 is in contact with the return members 300a and 300b 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 is connected to the 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 is connected to the side of the opening 131H in the ceiling wall 131U of the chamber body 131M opposite the side connected to the return member 300a. Therefore, the return members 300a and 300b electrically connect the second discharge electrode 134b to the chamber body 131M.

[0050] The chamber body 131M is electrically connected to the ground. Therefore, the second discharge electrode 134b is electrically connected to the ground via the spacer 187, the ground plate 137, the return members 300a and 300b, and the chamber body 131M. Alternatively, the spacer 187 can 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 can be directly connected, respectively. The return members 300a and 300b are preferably made of a material that is less likely to chemically react with the laser gas. Examples of such conductive materials include copper and nickel.

[0051] The first discharge electrode 134a is airtightly fixed to the surface of the electrical insulating plate 135 located on the inner space side of the discharge chamber 131 via a current introduction terminal 157, for example, formed by a bolt. Therefore, the first discharge electrode 134a is insulated from the chamber body 131M. The current introduction 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.

[0052] The charger 141 is a DC high-voltage power source that supplies electrical energy to the pulse compression circuit 150. A switch 151 is electrically connected to the charger 141 and controlled by the laser processor 190. When the switch 151 is switched from off to on, electrical energy from the charger 141 is supplied to the pulse compression circuit 150. The pulse compression circuit 150 generates a pulsed high voltage based on the electrical energy stored in the charger 141 and applies this high voltage to the first discharge electrode 134a.

[0053] When a high voltage is applied to the first discharge electrode 134a, a discharge occurs between the first discharge electrode 134a and the second discharge electrode 134b due to the potential difference between the first discharge electrode 134a and the second discharge electrode 134b. The energy of this discharge excites the laser medium within the discharge chamber 131, and the excited laser medium emits light when it transitions to a ground state.

[0054] A preionization electrode 180 is provided on the ground plate 137 to the side of the second discharge electrode 134b via a spacer 187 and an end of the return member 300a. The preionization electrode 180 includes a dielectric tube 181, a preionization inner electrode 183, and a preionization outer electrode 185.

[0055] The dielectric tube 181 is disposed longitudinally along the length of the second discharge electrode 134b and is, for example, a cylindrical tube. The dielectric tube 181 is made of, for example, alumina ceramic or sapphire. The preionization inner electrode 183 is a rod-shaped electrode disposed within the dielectric tube 181, extending longitudinally along the tube. The preionization inner electrode 183 is made of, for example, copper or brass. The preionization outer electrode 185 is disposed between the dielectric tube 181 and the second discharge electrode 134b, extending longitudinally along the tube 181, and secured to a spacer 187. If the spacer 187 is omitted, the preionization outer electrode 185 is secured to the second discharge electrode 134b. The end of the preionization outer electrode 185 contacts the outer circumference of the dielectric tube 181. However, as long as the corona discharge described below is generated, a portion of the end of the preionization outer electrode 185 does not need to contact the outer circumference of the dielectric tube 181.

[0056] 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 to the chamber body 131M via the ground plate 137 and return members 300a and 300b. Therefore, the preionization outer electrode 185 is electrically connected to the ground. By applying a high voltage 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 helps stabilize the glow discharge generated between the first discharge electrode 134a and the second discharge electrode 134b.

[0057] Figure 4This is an explanatory diagram showing the positioning of the ground plate 137 and the chamber body 131M. While the following illustrates 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 also applicable. The chamber body 131M can be divided into an upper portion 131Ma and a lower portion 131Mb, with an O-ring 131Mo sealing the gap between the upper portion 131Ma and the lower portion 131Mb. A downwardly recessed recess 137H is provided on the periphery of the upper surface 137U of the ground plate 137. A protrusion 131MT protruding toward the interior space is provided on the inner wall of the upper portion 131Ma, and an upwardly recessed recess 131MH is provided on the lower surface 131MS of the protrusion 131MT, opposite the recess 137H. Positioning pins 138A are inserted into recessed portion 137H of ground plate 137 and recessed portion 131MH of chamber body 131M, restricting horizontal movement of ground plate 137. Furthermore, lower surface 131MS of raised portion 131MT abuts upper surface 137U of ground plate 137, restricting vertical movement of ground plate 137. Ground plate 137 is then secured to chamber body 131M using bolts (not shown). This ensures that ground plate 137 is positioned relative to the inner wall of chamber body 131M.

[0058] Figure 5 This diagram illustrates the positioning of the second discharge electrode 134b and the grounding 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 grounding 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 grounding plate 137 to restrict horizontal movement of the second discharge electrode 134b. Furthermore, the upper surface 137U of the grounding plate 137 abuts the lower surface 134bS of the second discharge electrode 134b, restricting vertical movement of the second discharge electrode 134b. The second discharge electrode 134b is secured to the grounding plate 137 using bolts (not shown). In this manner, the second discharge electrode 134b is positioned relative to the grounding plate 137. As described above, the second discharge electrode 134 b is positioned with respect to the chamber body 131M via the ground plate 137 .

[0059] like Figure 3 As shown, a stabilizer 138a is provided on the side surface of the ground plate 137 on the side where the return member 300a is provided. Furthermore, a guide 138b is provided on the lower surface of the ground plate 137 on the side where the return member 300b is provided. Stabilizer 138a and guide 138b are components that rectify the flow of the laser gas so that it flows in the appropriate direction.

[0060] A cross-flow fan 149 and a heat exchanger 148 are disposed on the side of the discharge chamber 131 opposite to the second discharge electrode 134b, relative to the ground plate 137. The space in the discharge chamber 131 where the cross-flow fan 149 and the 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 disposed next to the cross-flow fan 149 and is a radiator connected to a pipe (not shown) through which a cooling medium flows. Figure 2 As shown, the cross flow fan 149 is connected to a motor 149a disposed outside the discharge chamber 131 and rotates by the rotation of the motor 149a. As the cross flow fan 149 rotates, the laser gas filled into the inner space of the discharge chamber 131 is rotated as shown in FIG. Figure 3 The laser gas circulates as indicated by the arrows. Specifically, crossflow fan 149 causes the laser gas to flow between first discharge electrode 134a and second discharge electrode 134b in a direction approximately perpendicular to the laser optical axis. This flow of laser gas positions return member 300a upstream of the laser gas, while return member 300b downstream of the laser gas. At least a portion of the circulating laser gas passes through heat exchanger 148 to adjust its temperature.

[0061] Laser gas is supplied from a laser gas supply source (not shown) through a pipe (not shown). The laser gas in the discharge chamber 131 is passed through a halogen filter to remove F2 gas, and then exhausted into the housing 110 through a pipe (not shown) by an exhaust pump (not shown).

[0062] A pair of windows 139a and 139b are provided on the wall of the discharge chamber 131. Window 139a is located at one end of the discharge chamber 131 in the direction of laser light travel, while window 139b is located at the other end in the same direction. Windows 139a and 139b sandwich the space between the first discharge electrode 134a and the second discharge electrode 134b. Windows 139a and 139b can also be tilted to form a Brewster angle with respect to the direction of laser light travel to suppress laser light reflection. As described later, the oscillating laser light is emitted outside the discharge chamber 131 through 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, resulting in pulsed laser light.

[0063] The narrowband module 145 includes a housing 145a, a prism 145b, a grating 145c, and a rotating stage (not shown) disposed in the interior of the housing 145a. The housing 145a has an opening, and the housing 145a is connected to the rear side of the discharge chamber 131 through the opening.

[0064] The prism 145b widens the beam width of the light emitted from the window 139a, causing the light to enter the grating 145c. In addition, the prism 145b reduces the beam width of the reflected light from the grating 145c and returns the light to the internal space of the discharge chamber 131 through the window 139a. The prism 145b is supported by a rotating table (not shown) and rotated by the rotating table. The rotation of the prism 145b changes the incident angle of the light relative to the grating 145c, and the wavelength of the light returned from the grating 145c through the prism 145b to the discharge chamber 131 can be selected. Figure 2 , an example in which one prism 145 b is arranged is shown, but at least one prism only needs to be arranged.

[0065] The surface of grating 145c is made of a high-reflectivity material and has multiple grooves spaced at regular intervals. The cross-sectional shape of each groove is, for example, a right triangle. Light incident on grating 145c from prism 145b, when reflected by these grooves, is diffracted in a direction corresponding to its wavelength. Grating 145c is configured by Littrow so that the angle of incidence of light incident on grating 145c from prism 145b matches the diffraction angle of diffracted light of a desired wavelength. As a result, light near the desired wavelength is returned to discharge chamber 131 via prism 145b.

[0066] Output coupling mirror 147 is located within the interior of optical 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 monitoring module 160, while reflecting the remaining portion, which returns through window 139b to the interior of discharge chamber 131. Thus, grating 145c and output coupling mirror 147 form a Fabry-Perot laser resonator.

[0067] Monitoring module 160 is disposed on the optical path of the laser light emitted from output coupling mirror 147. Monitoring module 160 includes a housing 161, a beam splitter 163 disposed within the interior of housing 161, and a light sensor 165. Housing 161 has an opening formed therein, and the interior of housing 161 communicates with the interior of optical tube 147a through the opening.

[0068] Beam splitter 163 transmits a portion of the laser light emitted from output coupling mirror 147 toward aperture 170 and reflects the other portion toward the light receiving surface of optical sensor 165. Optical sensor 165 outputs a signal indicating energy E of the laser light incident on the light receiving surface to laser processor 190.

[0069] The laser processor 190 of the present disclosure is a processing device comprising a storage device 190a storing a control program and a CPU (Central Processing Unit) 190b executing the control program. Laser processor 190 is specifically configured or programmed to perform the various processes included in the present disclosure. Furthermore, laser processor 190 controls the entire gas laser device 100.

[0070] The laser processor 190 exchanges various signals with the exposure processor 230 of the exposure device 200. For example, the laser processor 190 receives signals indicating the emission trigger Tr (described later) and the target energy Et from the exposure processor 230. The target energy Et is the target value for the laser energy used in the exposure process. The laser processor 190 controls the charge 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. By controlling the charge voltage, the laser energy is controlled. Furthermore, the laser processor 190 is electrically connected to the aperture 170 and controls the opening and closing of the aperture 170.

[0071] Aperture 170 is disposed on the optical path within the interior space of optical tube 171, which communicates with an opening formed on the side of housing 161 of monitoring module 160 opposite to the side connected to optical tube 147a. A purge gas is supplied and filled into the interior spaces of optical tubes 171 and 147a, and the interior spaces of housings 161 and 145a. The purge gas contains an inert gas such as nitrogen (N2). The purge gas is supplied from a purge gas supply source (not shown) through piping (not shown). Furthermore, optical tube 171 communicates with exposure device 200 through an opening in housing 110 and optical tube 600 connecting housing 110 and exposure device 200. Laser light passing through aperture 170 enters exposure device 200.

[0072] Next, the structure of the return members 300a and 300b will be described.

[0073] In this example, the return members 300a and 300b have the same structure, so only the return member 300a will be described. Figure 6 300a. Figure 6 As shown, the return member 300a is formed, for example, by punching and bending a metal plate, and includes a plate-shaped first fixing portion 311, a plate-shaped second fixing portion 312, and a ladder portion 320 connecting the first fixing portion 311 and the second fixing portion 312. The thickness of the punched and bent metal plate is, for example, 1.0 mm to 1.2 mm.

[0074] The first fixing portion 311 is a member having a substantially rectangular main surface, and is attached to the top wall 131U of the chamber body 131M so that its longitudinal direction is along the longitudinal direction of the first discharge electrode 134a. Figure 6 The second fixing portion 312 is substantially the same shape as the first fixing portion 311 and is attached to the spacer 187 such that its longitudinal direction is along the longitudinal direction of the second discharge electrode 134b.

[0075] 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 component 300a is formed by punching a metal plate, so the connection is not performed by welding or brazing, but is a state of continuous metal phase. Each linear portion 321 is connected to the first fixing portion 311 and the second fixing portion 312, and the plurality of linear portions 321 are arranged in parallel along the length direction of the first discharge electrode 134a and the second discharge electrode 134b, wherein the length direction of the first discharge electrode 134a and the second discharge electrode 134b is along the optical axis of the laser. The width of the gap between adjacent linear portions 321 is, for example, 19.0 mm to 19.5 mm, such as Figure 3 As shown, laser gas can pass through this gap.

[0076] The connection portion between the first fixing portion 311 and each linear portion 321, or the vicinity of the connection portion, is bent, so that the direction in which each linear portion 321 is arranged is not parallel to the main surface of the first fixing portion 311. Furthermore, the connection portion between the second fixing portion 312 and each linear portion 321, or the vicinity of the connection portion, is bent, so that the direction in which each linear portion 321 is arranged is not parallel to the main surface of the second fixing portion 312. Furthermore, the main surfaces of the first fixing portion 311 and the second fixing portion 312 are not parallel to each other, and form an angle of approximately 90 degrees, for example.

[0077] 2.2 Action

[0078] Next, the operation of the gas laser device 100 according to the comparative example will be described.

[0079] Before the gas laser device 100 emits laser light, purge gas is filled from a purge gas supply source (not shown) into the interior spaces of the optical tubes 147a, 171, and 600, and the interior spaces of the housings 145a and 161. Furthermore, laser gas is supplied from a laser gas supply source (not shown) into the interior space of the discharge chamber 131. While the laser gas is being 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 interior space of the discharge chamber 131. At this time, the gap between the chamber body 131M and the electrically insulating plate 135 is sealed by the metal seal 133, preventing the laser gas from leaking outside the discharge chamber 131.

[0080] The laser gas passes through the cross flow fan 149 as Figure 3 The laser gas circulates as indicated by the arrows. At this time, the laser gas passes between the linear portions 321 of the return member 300a, located upstream of the first and second discharge electrodes 134a, 134b. The laser gas then passes between the first and second discharge electrodes 134a, 134b, and between the linear portions 321 of the return member 300b, located downstream of the first and second discharge electrodes 134a, 134b.

[0081] When the laser processor 190 receives a signal indicating the target energy Et and a signal indicating the emission trigger Tr from the exposure processor 230, it controls the gas laser device 100 to emit laser light. Upon receiving the signal indicating the target energy Et, the laser processor 190 closes the aperture 170 and activates the charger 141. Furthermore, the laser processor 190 turns on the switch 151 of the pulse compression circuit 150. This causes current from the charger 141 to flow into the pulse compression circuit 150, applying a pulsed high voltage to the first discharge electrode 134a via the current introduction terminal 157. Furthermore, the timing of applying the high voltage between the preionization inner electrode 183 and the preionization outer electrode 185 is slightly earlier than the timing of applying the high voltage between the first discharge electrode 134a and the second discharge electrode 134b. When the 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 tube 181 and the preionization outer electrode 185, emitting ultraviolet light. When ultraviolet light irradiates the laser gas between the first and second discharge electrodes 134a, 134b, it is pre-ionized. After pre-ionization, as described above, when a high voltage is applied between the first and second discharge electrodes 134a, 134b, a main discharge occurs between the first and second discharge electrodes 134a, 134b. Because the return members 300a and 300b are connected to the chamber body 131M, the current of the main discharge flows through the return members 300a and 300b to the chamber body 131M.

[0082] This main discharge causes the laser medium contained in the laser gas between the first discharge electrode 134a and the second discharge electrode 134b to enter an excited state. When the laser medium returns to its ground state, it emits light. This light resonates between the grating 145c and the output coupling mirror 147. Each time it passes through the discharge space between the first discharge electrode 134a and the second discharge electrode 134b within the discharge chamber 131, it is amplified, causing laser oscillation. A portion of the resonant laser light passes through the output coupling mirror 147 as pulsed laser light and travels toward the beam splitter 163.

[0083] A portion of the laser light that has reached 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 energy E and target energy Et falls within an allowable range. Once the difference ΔE falls within the allowable range, laser processor 190 transmits a reception preparation completion signal indicating that reception preparation of light emission trigger Tr has been completed to exposure processor 230.

[0084] Upon receiving the reception preparation completion signal, the exposure processor 230 transmits a light emission trigger Tr to the laser processor 190. When the laser processor 190 opens the aperture 170 in synchronization with the reception of the light emission trigger Tr, the laser light that has passed through the aperture 170 enters the exposure device 200. This laser light is, for example, a pulsed laser light having a central wavelength of 193 nm.

[0085] 3.Topic

[0086] Figure 7 This is a cross-sectional view of the chamber apparatus 101 of the comparative example, taken parallel to the laser optical axis. One factor that determines the service life of the chamber apparatus 101 is the wear of the first discharge electrode 134a. Through experiments, the inventors discovered that the current flowing from the second discharge electrode 134b into the chamber body M through the linear portion 321 near the longitudinal ends of the return members 300a and 300b is sometimes smaller than the current flowing near the longitudinal center of the return members 300a and 300b. If the return current flowing through the return members 300a and 300b is unevenly distributed along the longitudinal direction, it can be inferred that the main discharge is also uneven along the longitudinal directions of the first and second discharge electrodes 134a and 134b. If the main discharge is uneven, the first discharge electrode 134a is likely to wear unevenly, potentially shortening the service life due to the faster wear of the portion.

[0087] The reason for this is believed to be that the current that should flow through the linear portion 321 near the longitudinal ends of the return members 300a and 300b instead flows through the fixed portion between the ground plate 137 and the inner wall of the chamber body 131M. Therefore, it is expected that by reducing the current that flows through the fixed portion between the ground plate 137 and the inner wall of the chamber body 131M, the uniformity of the main discharge can be improved. This is believed to extend the life of the first discharge electrode 134a and the chamber apparatus 101. Therefore, the following embodiments illustrate examples of laser chamber apparatuses 101 and gas laser apparatuses 100 that can achieve extended life.

[0088] 4. Description of Implementation Method 1

[0089] Next, the chamber apparatus 101 according to Embodiment 1 will be described. Components identical to those described above are denoted by the same reference numerals, and duplicate descriptions will be omitted unless otherwise specified. In some drawings, for ease of illustration, portions of components may be omitted or simplified. For identical components, only some reference numerals may be assigned, while others may be omitted.

[0090] 4.1 Structure

[0091] Figure 8 is with Figure 7 The figure also shows 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 serves as an insulator, instead of the ground plate 137. Therefore, in the chamber apparatus 101, there is no electrical continuity between the second discharge electrode 134b and the chamber body 131M 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 ceramic, for example, alumina ceramic.

[0092] 4.2 Function and effect

[0093] In the chamber apparatus 101 of this embodiment, current does not flow from the second discharge electrode 134b to the support member 400. Therefore, the return current flowing through the return members 300a and 300b can be more uniform in the longitudinal direction. Improving the longitudinal uniformity of the return current also improves the longitudinal uniformity of the discharge between the first and second discharge electrodes 134a and 134b. Consequently, uneven wear of the first discharge electrode 134a can be suppressed, extending the life of the gas laser apparatus 100. Furthermore, the shape of the support member 400 is the same as that of the ground plate 137 of the comparative example, thereby maintaining the positioning structure of the second discharge electrode 134b.

[0094] The return members 300a, 300b and the spacer 187 are preferably provided from one end to the other in the longitudinal direction of the second discharge electrode 134b, but are not limited thereto. The return members 300a, 300b and the spacer 187 may be located slightly outward from both ends in the longitudinal direction of the second discharge electrode 134b, or slightly inward from both ends.

[0095] 5. Description of Implementation Method 2

[0096] The chamber apparatus 101 according to Embodiment 2 will be described. Components identical to those described above are denoted by the same reference numerals, and duplicate descriptions will be omitted unless otherwise specified. In some drawings, for ease of illustration, portions of components may be omitted or simplified. For identical components, only some reference numerals may be assigned, while others may be omitted.

[0097] 5.1 Structure

[0098] Figure 9 is with Figure 7 Similarly, a diagram showing the chamber device 101 according to this embodiment is shown. Figure 10: is a cross-sectional view of the chamber device 101 of this embodiment perpendicular to the optical axis of the laser. Figure 11 It is an explanatory diagram showing how the placing member 500 and the supporting member 400 are positioned, and how the second discharge electrode 134 b and the placing member 500 are positioned.

[0099] like Figure 9 As shown, the main difference between the support member 400 of this embodiment and the first embodiment is 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 ceramic, for example, alumina ceramic. The thickness of the mounting member 500 in the Y direction is preferably at least 1.5 mm. The support member 400 of this embodiment can be made of an insulator or conductive material. The material of the support member 400 can also be a metal such as aluminum. Furthermore, to maintain the distance between the first discharge electrode 134a and the second discharge electrode 134b to be the same as in the comparative example, the thickness of the second discharge electrode 134b in the Y direction can be reduced by the thickness of the mounting member 500.

[0100] like Figure 10 As shown, in this embodiment, the return members 300 a and 300 b do not come into contact with the support member 400 .

[0101] In addition, in this embodiment, the second discharge electrode 134b is positioned relative to the mounting member 500. Figure 11 As shown, a recessed portion 400H that is recessed downward is provided on the upper surface 400U of the support member 400. A recessed portion 500H2 that is recessed upward is provided on the lower surface 500S of the carrier member 500 at a position opposite to the recessed portion 400H. Positioning pins 138D are inserted into the recessed portion 400H of the support member 400 and the recessed portion 500H2 of the carrier member 500 to restrict the horizontal movement of the carrier member 500. In addition, the vertical movement of the carrier member 500 is restricted by the contact between the lower surface 500S of the carrier member 500 and the upper surface 400U of the support member 400, and the carrier member 500 is fixed to the support member 400 using bolts, etc., not shown. In this way, the carrier member 500 is positioned relative to the support member 400.

[0102] The upper surface 500U of the mounting member 500 is provided with a downwardly recessed recess 500H. The lower surface 134bS of the second discharge electrode 134b is provided with an upwardly recessed recess 134bH at a position opposite 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, restricting horizontal movement of the second discharge electrode 134b. Furthermore, the lower surface 134bS of the second discharge electrode 134b abuts the upper surface 500U of the mounting member 500, restricting vertical movement of the second discharge electrode 134b. The second discharge electrode 134b is secured to the mounting member 500 using bolts (not shown). This positions the second discharge electrode 134b relative to the mounting member 500.

[0103] 5.2 Function and effect

[0104] In the chamber apparatus 101 of this embodiment, the mounting member 500 is constructed of an insulator. Therefore, current can flow primarily to the ground line through the return members 300a and 300b, and the return current flowing through the return members 300a and 300b can be more uniform in the longitudinal direction. Improving the longitudinal uniformity of the return current improves the longitudinal uniformity of the discharge between the first discharge electrode 134a and the second discharge electrode 134b. Consequently, uneven wear of the first discharge electrode 134a can be suppressed, extending the life of the gas laser apparatus 100. Furthermore, the mounting member 500 can be implemented in a shape that is smaller than the support member 400 and easier to process. This facilitates positioning of the second discharge electrode 134b, and the support member 400 can be made of inexpensive metal materials such as aluminum, thereby reducing costs.

[0105] The above description is not limiting but merely illustrative. Therefore, it is obvious to those skilled in the art that changes can be made to the embodiments of the present disclosure without departing from the scope of the claims. In addition, it is obvious to those skilled in the art that the embodiments of the present disclosure can be used in combination. Unless otherwise specified, the terms used in this specification and claims should be interpreted as "non-restrictive" terms. For example, terms such as "including", "having", "having", and "having" should be interpreted as "not excluding the presence of constituent elements other than the recorded constituent elements". In addition, the modifier "1" should be interpreted as "at least 1" or "1 or more". In addition, terms such as "at least one of A, B and C" should be interpreted as "A", "B", "C", "A+B", "A+C", "B+C" or "A+B+C", and should also be interpreted as including combinations of them with contents other than "A", "B" and "C".

Claims

1. A laser chamber device for emitting laser light, wherein: The laser chamber device comprises: Chamber body; a first discharge electrode disposed in the interior space of the chamber body with its length direction along the optical axis of the laser light; a second discharge electrode disposed in the internal space so as to face the first discharge electrode with its longitudinal direction along the optical axis of the laser beam; a return member electrically connected to the chamber body and electrically connected to the second discharge electrode in a range from one end side to the other end side in the longitudinal direction of the second discharge electrode; as well as a supporting member fixed to the chamber body and supporting the second discharge electrode, The second discharge electrode is not electrically connected to the chamber body via the support member.

2. The laser chamber device according to claim 1, wherein: The supporting member is made of an insulator.

3. The laser chamber device according to claim 1, wherein: The supporting member supports the second discharge electrode via a placing member made of an insulator.

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

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

6. The laser chamber device according to claim 1, wherein: The support member is positioned to the chamber body by positioning pins.

7. The laser chamber device according to claim 3, wherein: The thickness of the mounting member is greater than or equal to 1.5 mm.

8. A gas laser device comprising a laser chamber device for emitting laser light, wherein: The laser chamber device comprises: Chamber body; a first discharge electrode disposed in the interior space of the chamber body with its length direction along the optical axis of the laser light; a second discharge electrode disposed in the internal space so as to face the first discharge electrode with its longitudinal direction along the optical axis of the laser beam; a return member electrically connected to the chamber body and electrically connected to the second discharge electrode in a range from one end side to the other end side in the longitudinal direction of the second discharge electrode; as well as a supporting member fixed to the chamber body and supporting the second discharge electrode, The second discharge electrode is not electrically connected to the chamber body via the support member.

9. A method for manufacturing an electronic device, wherein: The manufacturing method of the electronic device comprises the following steps: outputting laser light generated by the gas laser device to an exposure device; and exposing the laser light on a photosensitive substrate in the exposure device to manufacture an electronic device, The gas laser device includes a laser chamber device for emitting the laser light. The laser chamber device for emitting the laser light comprises: Chamber body; a first discharge electrode disposed in the interior space of the chamber body with its length direction along the optical axis of the laser light; a second discharge electrode disposed in the internal space so as to face the first discharge electrode with its longitudinal direction along the optical axis of the laser beam; a return member electrically connected to the chamber body and electrically connected to the second discharge electrode in a range from one end side to the other end side in the longitudinal direction of the second discharge electrode; as well as a supporting member fixed to the chamber body and supporting the second discharge electrode, The second discharge electrode is not electrically connected to the chamber body via the support member.

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