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

Abstract

A laser chamber device according to one aspect of the present disclosure is provided with: a chamber; a first discharge electrode; a second discharge electrode; a conductive holder that holds the first discharge electrode; a first dielectric tube disposed along the first discharge electrode; a second dielectric tube facing the first dielectric tube and disposed along the second discharge electrode; a first preionization electrode disposed in the internal space of the first dielectric tube; a second preionization electrode disposed in the internal space of the second dielectric tube; a first insulating holder disposed on the conductive holder and holding one end of each of the first dielectric tube and the second dielectric tube; and a second insulating holder disposed on the conductive holder and holding the other end portions of the first dielectric tube and the second dielectric tube.

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 improve resolution as semiconductor integrated circuits become increasingly miniaturized and highly integrated. Consequently, there has been a trend toward shortening the wavelength of light emitted by 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 the KrF excimer laser device and the ArF excimer laser device is as wide as 350pm to 400pm. Therefore, if the projection lens is made of a material that allows ultraviolet light such as KrF and ArF lasers to pass through, chromatic aberration may 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 degree that the chromatic aberration can be ignored. Therefore, in order to narrow the spectral line width, a narrowing module (Line Narrowing Module: LNM) including narrowing elements (etalon, grating, etc.) is sometimes provided in the laser resonator of the gas laser device. Hereinafter, the gas laser device that narrows the spectral line width will be 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. 2012-033799

[0007] Patent Document 2: Japanese Patent Application Laid-Open No. 2004-186310

[0008] Patent Document 3: Japanese Patent Application Laid-Open No. 11-168254 Summary of the Invention

[0009] A laser chamber device according to one aspect of the present disclosure generates laser light by discharge-exciting preionized laser gas. The device includes: a chamber that contains the laser gas; a first discharge electrode disposed within the chamber; a second discharge electrode disposed within the chamber opposite the first discharge electrode and, together with the first discharge electrode, causing discharge-excitation of the laser gas; a conductive holder that holds the first discharge electrode; a first dielectric tube disposed along the first discharge electrode; a second dielectric tube disposed opposite the first dielectric tube and along the second discharge electrode; a first preionization electrode disposed within the interior of the first dielectric tube; a second preionization electrode disposed within the interior of the second dielectric tube; a first insulating holder disposed within the conductive holder and holding one end portion of the first and second dielectric tubes; and a second insulating holder disposed within the conductive holder and holding the other end portions of the first and second dielectric tubes.

[0010] A gas laser device according to one aspect of the present disclosure includes a laser chamber device that generates laser light by discharge-exciting preionized laser gas. The laser chamber device includes: a chamber that accommodates the laser gas; a first discharge electrode disposed within the chamber; a second discharge electrode disposed within the chamber opposite the first discharge electrode and, together with the first discharge electrode, discharge-exciting the laser gas; a conductive holder that holds the first discharge electrode; a first dielectric tube disposed along the first discharge electrode; a second dielectric tube disposed opposite the first dielectric tube and along the second discharge electrode; a first preionization electrode disposed within the interior of the first dielectric tube; a second preionization electrode disposed within the interior of the second dielectric tube; a first insulating holder disposed on the conductive holder and holding one end portion of the first and second dielectric tubes; and a second insulating holder disposed on the conductive holder and holding the other end portions of the first and second dielectric tubes.

[0011] A method for manufacturing an electronic device according to one aspect of the present disclosure is a method for manufacturing an electronic device, the method comprising the following steps: generating laser light using a gas laser device including a laser chamber device; outputting the laser light to an exposure device; and exposing the laser light on a photosensitive substrate in the exposure device to manufacture the electronic device, wherein the laser chamber device comprises: a chamber that accommodates laser gas; a first discharge electrode disposed inside the chamber; a second discharge electrode disposed inside the chamber opposite to the first discharge electrode and, together with the first discharge electrode, causing discharge excitation of the laser gas; and a conductive retaining member. , which holds a first discharge electrode; a first dielectric tube, which is arranged along the first discharge electrode; a second dielectric tube, which is opposite to the first dielectric tube and arranged along the second discharge electrode; a first pre-ionization electrode, which is arranged in the interior space of the first dielectric tube; a second pre-ionization electrode, which is arranged in the interior space of the second dielectric tube; a first insulating holder, which is arranged on the conductive holder and holds each end portion on one side of the first dielectric tube and the second dielectric tube; and a second insulating holder, which is arranged on the conductive holder and holds each end portion on the other side of the first dielectric tube and the second dielectric tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Hereinafter, several embodiments of the present disclosure will be described with reference to the accompanying drawings, merely as examples.

[0013] Figure 1 It is a side view schematically showing the structure of a gas laser device according to a comparative example.

[0014] Figure 2 It is a cross-sectional view showing the structure of a laser chamber device according to a comparative example.

[0015] Figure 3 This is a diagram of a laser cavity device according to a comparative example as viewed from the output coupling mirror side.

[0016] Figure 4 This is a diagram of a laser cavity device according to a comparative example as viewed from the narrowband module side.

[0017] Figure 5 This is a circuit diagram schematically showing the configuration of a PPM and a pre-ionization discharge unit.

[0018] Figure 6 This is a diagram for explaining the problems of the comparative example.

[0019] Figure 7 This is a side view schematically showing the structure of the gas laser device according to the first embodiment.

[0020] Figure 8 It is a cross-sectional view showing the structure of the laser chamber device according to the first embodiment.

[0021] Figure 9This is a diagram of the laser cavity device according to the first embodiment as viewed from the output coupling mirror side.

[0022] Figure 10 This is a diagram of the laser chamber device according to the first embodiment as viewed from the bandwidth narrowing module side.

[0023] Figure 11 This is a perspective view of the first insulating holder as seen from one side.

[0024] Figure 12 This is a perspective view of the first insulating holder as seen from the other side.

[0025] Figure 13 This is a diagram showing how the ground plate of the first embodiment is connected to a pair of conductive holding frames.

[0026] Figure 14 This is a cross-sectional view showing the structure of a laser chamber device according to a first modification of the first embodiment.

[0027] Figure 15 This is a diagram of a laser cavity device according to a first modification of the first embodiment as viewed from the output coupling mirror side.

[0028] Figure 16 This is a diagram showing a laser chamber device according to a first modification of the first embodiment as viewed from the side of a narrowband module.

[0029] Figure 17 This is a diagram of a laser chamber device according to a second modified example of the first embodiment as viewed from the output coupling mirror side.

[0030] Figure 18 This is a diagram showing a laser chamber device according to a second modification of the first embodiment as viewed from the side of the bandwidth narrowing module.

[0031] Figure 19 It is a cross-sectional view showing the structure of a laser chamber device according to a second embodiment.

[0032] Figure 20 This is a diagram of the laser cavity device according to the second embodiment as viewed from the output coupling mirror side.

[0033] Figure 21 This is a diagram of the laser chamber device according to the second embodiment as viewed from the bandwidth narrowing module side.

[0034] Figure 22 This is a diagram showing a state where the ground plate of the second embodiment is connected to a pair of conductive holding frames.

[0035] Figure 23 It is a cross-sectional view showing the structure of a laser chamber device according to a first modified example of the second embodiment.

[0036] Figure 24This is a diagram of a laser cavity device according to a first modified example of the second embodiment as viewed from the output coupling mirror side.

[0037] Figure 25 This is a diagram showing a laser chamber device according to a first modification of the second embodiment as viewed from the bandwidth narrowing module side.

[0038] Figure 26 This is a diagram of a laser cavity device according to a second modification of the second embodiment as viewed from the output coupling mirror side.

[0039] Figure 27 This is a diagram showing a laser chamber device according to a second modified example of the second embodiment as viewed from the side of the bandwidth narrowing module.

[0040] Figure 28 This is a diagram for explaining abnormal discharge that may occur in the laser cavity device according to the second embodiment.

[0041] Figure 29 It is a cross-sectional view showing the structure of a laser chamber device according to a third embodiment.

[0042] Figure 30 This is a cross-sectional view of the first insulating holding member cut along the groove.

[0043] Figure 31 It is a cross-sectional view showing the structure of a laser chamber device according to a first modified example of the third embodiment.

[0044] Figure 32 It is a perspective view showing the structure of a first insulating holder according to a third embodiment.

[0045] Figure 33 This is a cross-sectional view showing the structure of a laser chamber device according to a second modified example of the third embodiment.

[0046] Figure 34 It is a perspective view showing the structure of the cover.

[0047] Figure 35 It is a cross-sectional view showing a portion of the first insulating holder.

[0048] Figure 36 It is a cross-sectional view showing a portion of the first insulating holder.

[0049] Figure 37 It is a diagram schematically showing a configuration example of an exposure apparatus. DETAILED DESCRIPTION

[0050] <Content>

[0051] 1. Comparative Example

[0052] 1.1 Gas laser device

[0053] 1.1.1 Structure

[0054] 1.1.2 Action

[0055] 1.2PPM and pre-ionization discharge unit

[0056] 1.2.1 Structure

[0057] 1.2.2 Action

[0058] 1.3 Topics

[0059] 2. First Implementation

[0060] 2.1 Structure and Action

[0061] 2.2 Effect

[0062] 2.3 Variations

[0063] 2.3.1 First Modification

[0064] 2.3.2 Second Modification

[0065] 3. Second Implementation

[0066] 3.1 Structure and Action

[0067] 3.2 Effect

[0068] 3.3 Variations

[0069] 3.3.1 First Modification

[0070] 3.3.2 Second Modification

[0071] 4. Third Implementation

[0072] 4.1 Structure and Action

[0073] 4.2 Effect

[0074] 4.3 Variations

[0075] 4.3.1 First Modification

[0076] 4.3.2 Second Modification

[0077] 4.3.3 Third Modification

[0078] 5. Other variations

[0079] 6. Method for manufacturing electronic devices

[0080] 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, the structures and actions described in the embodiments may not all be required as the structures and actions of the present disclosure. In addition, the same reference numerals are given to the same components, and repeated descriptions are omitted.

[0081] 1. Comparative Example

[0082] First, comparative examples of the present disclosure will be described. The comparative examples of the present disclosure are methods that the applicant recognizes as being known only to the applicant and are not publicly known examples that the applicant recognizes.

[0083] 1.1 Gas laser device

[0084] 1.1.1 Structure

[0085] use Figure 1 The structure of a gas laser device 2 according to a comparative example will be described. Figure 1 1 is a side view schematically showing the structure of the gas laser device 2. The gas laser device 2 is a discharge-excitation type gas laser device that excites laser gas by discharge, and is, for example, an excimer laser device.

[0086] exist Figure 1 In the figure, the direction of travel of the pulsed laser light PL output from the gas laser device 2 is defined as the Z direction. The discharge direction, described later, is defined as the Y direction. Furthermore, the direction perpendicular to the Z and Y directions is defined as the X direction. The pulsed laser light PL is an example of a "laser" in the technology disclosed herein.

[0087] exist Figure 1 In FIG, the gas laser device 2 includes a laser chamber device 3, a charger 11, a pulse power module (PPM) 12, a pulse energy measurement unit 13, a laser control processor 14, and a laser resonator. The laser resonator is composed of a narrowband module 15 and an output coupling mirror 16.

[0088] The laser chamber device 3 includes a chamber 10. The chamber 10 is a metal container formed, for example, of aluminum with a nickel plating applied to its surface. Inside the chamber 10, a main discharge portion 20, a ground plate 21, a pair of conductive holding frames 22, a first dielectric tube 23a, a second dielectric tube 23b, a preionization inner electrode 24, and a preionization outer electrode (described later) are provided.

[0089] The chamber 10 contains a laser gas containing fluorine. The laser gas contains, for example, rare gases such as argon, krypton, and xenon, buffer gases such as neon and helium, and halogen gases such as fluorine and chlorine.

[0090] An opening is formed in the chamber 10. An electrical insulating plate 26 in which a feedthrough 25 is embedded is attached to the chamber 10 via an O-ring (not shown) to close the opening. The PPM 12 is placed on the electrical insulating plate 26. The chamber 10 is grounded.

[0091] The PPM 12 includes a charging capacitor C0, described later, and is connected to the main discharge section 20 via a feedthrough 25. The PPM 12 includes a switch SW for discharging the main discharge section 20. The charger 11 is connected to the charging capacitor C0 of the PPM 12. Hereinafter, the glow discharge generated in the main discharge section 20 is referred to as the main discharge.

[0092] The main discharge section 20 is composed of a cathode electrode 20a and an anode electrode 20b. The cathode electrode 20a and the anode electrode 20b each extend in the Z direction. The anode electrode 20b is disposed within the chamber 10. The cathode electrode 20a is disposed opposite the anode electrode 20b within the chamber 10 and, together with the anode electrode 20b, excites the laser gas discharge. The space between the discharge surfaces of the cathode electrode 20a and the anode electrode 20b is referred to as the discharge space 27. The anode electrode 20b is an example of the "first discharge electrode" in the disclosed technology, and the cathode electrode 20a is an example of the "second discharge electrode" in the disclosed technology.

[0093] The surface of the cathode electrode 20a opposite to the discharge surface is held by an electrical insulating plate 26 and connected to the feedthrough 25. The surface of the anode electrode 20b opposite to the discharge surface is held by a ground plate 21.

[0094] The ground plate 21 is connected to the chamber 10 via a pair of conductive holding frames 22. One of the conductive holding frames 22 is connected to one end of the ground plate 21, and the other is connected to the other end of the ground plate 21. The chamber 10 is grounded. Therefore, the ground plate 21 is grounded.

[0095] The first dielectric tube 23a and the second dielectric tube 23b extend in the Z direction. The first dielectric tube 23a faces a side surface of the cathode electrode 20a and is arranged along the length of the cathode electrode 20a. The second dielectric tube 23b faces a side surface of the anode electrode 20b and is arranged along the anode electrode 20b. The preionization inner electrode 24 is inserted through the interior spaces of the first dielectric tube 23a and the second dielectric tube 23b. The first dielectric tube 23a and the second dielectric tube 23b generate ultraviolet light to preionize the laser gas.

[0096] The first dielectric tube 23a is attached to the electrical insulating plate 26 via a pair of first dielectric tube holders 30a. One of the pair of first dielectric tube holders 30a holds one end of the first dielectric tube 23a, and the other holds the other end of the first dielectric tube 23a.

[0097] The second dielectric tube 23b is attached to the ground plate 21 via a pair of second dielectric tube holders 30b. One of the pair of second dielectric tube holders 30b holds one end of the second dielectric tube 23b, and the other holds the other end of the second dielectric tube 23b.

[0098] Fan 17 is a cross-flow fan for circulating laser gas within chamber 10. It is located on the opposite side of discharge space 27 from ground plate 21. A motor 17a is connected to chamber 10 to drive fan 17. Laser gas blown from fan 17 flows into discharge space 27. The flow direction of the laser gas flowing into discharge space 27 is approximately parallel to the X-direction. The laser gas flowing out of discharge space 27 is drawn into fan 17 via a heat exchanger (not shown).

[0099] Furthermore, laser gas supply device 18a and laser gas exhaust device 18b are connected to chamber 10. Laser gas supply device 18a includes a valve and a flow control valve and is connected to a gas cylinder containing laser gas. Laser gas exhaust device 18b includes a valve and an exhaust pump.

[0100] Windows 10a and 10b for emitting light generated in the chamber 10 to the outside are provided at the ends of the chamber 10. The chamber 10 is arranged so that the optical path of the optical resonator passes through the discharge space 27 and the windows 10a and 10b.

[0101] The narrowband module 15 includes a prism 15a and a grating 15b. The prism 15a widens the beam width of light emitted from the chamber 10 through the window 10a and transmits the light toward the grating 15b.

[0102] Grating 15b is arranged in a Littrow configuration, where the incident angle and diffraction angle are equal. Grating 15b is a wavelength-selective element that selectively extracts light near a specific wavelength based on the diffraction angle. The spectral width of the light that returns from grating 15b to chamber 10 via prism 15a is narrowed.

[0103] The output coupling mirror 16 transmits a portion of the light emitted from the chamber 10 through the window 10b and reflects the other portion to return it to the chamber 10. The surface of the output coupling mirror 16 is coated with a partial reflection film.

[0104] The light emitted from the chamber 10 reciprocates between the band narrowing module 15 and the output coupling mirror 16, and is amplified each time it passes through the discharge space 27. A portion of the amplified light is output as pulsed laser light PL via the output coupling mirror 16.

[0105] The pulse energy measurement unit 13 is arranged on the optical path of the pulse laser light PL outputted via the output coupling mirror 16. The pulse energy measurement unit 13 includes a beam splitter 13a, a focusing optical system 13b, and a photosensor 13c.

[0106] Beam splitter 13a transmits pulsed laser light PL with high transmittance and reflects a portion of the pulsed laser light PL toward focusing optical system 13b. Focusing optical system 13b focuses the light reflected by beam splitter 13a onto the light-receiving surface of optical sensor 13c. Optical sensor 13c measures the pulse energy of the light focused on the light-receiving surface and outputs the measured value to laser control processor 14.

[0107] Charger 11 is a high-voltage power source that supplies a charging voltage to charging capacitor C0 included in PPM 12. Switch SW of PPM 12 is controlled by laser control processor 14. When switch SW is switched from off to on, PPM 12 generates a high-voltage pulse based on the electrical energy stored in charging capacitor C0 and applies it to main discharge section 20.

[0108] The laser control processor 14 is a processing device comprising a storage device storing a control program and a CPU (Central Processing Unit) that executes the control program. The laser control processor 14 exchanges various signals with the exposure device controller 110 provided in the exposure device 100. For example, the exposure device controller 110 transmits information such as the target pulse energy of the pulsed laser light PL to be output to the exposure device 100 and an oscillation trigger signal to the laser control processor 14. Based on the various signals transmitted from the exposure device controller 110 and the measured pulse energy value, the laser control processor 14 uniformly controls the operation of the various components of the gas laser device 2.

[0109] Next, use Figures 2 to 4 The structures of the first dielectric tube holding portion 30 a and the second dielectric tube holding portion 30 b will be described. Figure 2 It is a cross-sectional view showing the structure of a laser cavity device 3 according to a comparative example. Figure 3 This is a diagram of the laser cavity device 3 according to the comparative example as viewed from the output coupling mirror 16 side. Figure 4 This is a diagram of the laser cavity device 3 of the comparative example as viewed from the side of the narrowband module 15. Figure 2 Shown along Figure 3 The cross section of line AA. In addition, Figure 3 and Figure 4 Arrows F are shown to indicate the direction of laser gas flow.

[0110] The first dielectric tube 23a is disposed on the upstream side of the laser gas relative to the cathode electrode 20a, and the second dielectric tube 23b is disposed on the upstream side of the laser gas relative to the anode electrode 20b.

[0111] The pair of first dielectric tube holders 30a are each composed of a base member 31a, a first member 32a, and a second member 33a. For example, the base member 31a is made of metal, while the first and second members 32a, 33a are insulating. The base member 31a is fixed to the insulating plate 26. The first and second members 32a, 33a are each screwed to the base member 31a, sandwiching the first dielectric tube 23a.

[0112] The pair of second dielectric tube holding portions 30b are composed of a base member 31b, a first member 32b, and a second member 33b. For example, the base member 31b is made of metal, and the first and second members 32b, 33b are insulating. The base member 31b is fixed to the ground plate 21. The first and second members 32b, 33b are each screwed to the base member 31b, sandwiching the second dielectric tube 23b.

[0113] The preionization inner electrode 24 includes a first preionization electrode 24a and a second preionization electrode 24b. The first preionization electrode 24a extends in the Z direction and is disposed within the interior space of the first dielectric tube 23a. The second preionization electrode 24b extends in the Z direction and is disposed within the interior space of the second dielectric tube 23b. The ends of the first preionization electrode 24a and the second preionization electrode 24b on the same side are connected to each other. This connection portion 24c extends in the Y direction. In this comparative example, the first preionization electrode 24a and the second preionization electrode 24b are formed from a single, U-shaped conductive component.

[0114] 1.1.2 Action

[0115] Next, the operation of the comparative example gas laser device 2 will be described. First, the laser control processor 14 controls the laser gas supply device 18a to supply laser gas into the chamber 10 and drives the motor 17a to rotate the fan 17. This circulates the laser gas in the chamber 10.

[0116] Upon receiving the target pulse energy from the exposure device controller 110 , the laser control processor 14 sets a charging voltage corresponding to the received target pulse energy for the charger 11 . Next, upon receiving the oscillation trigger signal from the exposure device controller 110 , the laser control processor 14 activates the switch SW of the PM 12 .

[0117] When switch SW of PPM 12 is turned from off to on, a voltage is applied between preionization inner electrode 24 and preionization outer electrode, and between cathode electrode 20a and anode electrode 20b. This generates a corona discharge between preionization inner electrode 24 and preionization outer electrode, generating ultraviolet light. This ultraviolet light irradiates the laser gas in discharge space 27, preionizing the laser gas.

[0118] When the voltage between cathode electrode 20a and anode electrode 20b reaches the dielectric breakdown voltage, a main discharge occurs in discharge space 27. When the main discharge occurs, the laser gas in discharge space 27 is excited to generate excimers. The generated excimers emit light when they transition from an excited state to a ground state.

[0119] The light emitted from the laser gas is reflected by the band-narrowing module 15 and the output coupling mirror 16, reciprocating within the laser resonator, thereby generating laser oscillation. The light narrowed by the band-narrowing module 15 is output from the output coupling mirror 16 as pulsed laser light PL. The pulsed laser light PL output from the output coupling mirror 16 is output toward the exposure device 100.

[0120] A portion of the pulse laser light PL output from the output coupling mirror 16 enters the pulse energy measuring unit 13 . The pulse energy measuring unit 13 measures the pulse energy of the incident pulse laser light PL and outputs the measured value to the laser control processor 14 .

[0121] The laser control processor 14 calculates the difference between the measured value of the pulse energy and the target pulse energy and performs feedback control on the charging voltage based on the calculated difference so that the measured value of the pulse energy becomes the target pulse energy.

[0122] 1.2PPM and pre-ionization discharge unit

[0123] 1.2.1 Structure

[0124] use Figure 5 The structures of the PPM 12 and the pre-ionization discharge unit 35 will be described. Figure 5 It is a circuit diagram schematically showing the configuration of the PPM 12 and the pre-ionization discharge unit 35 .

[0125] PPM 12 includes a switch SW, a transformer TC, magnetic switches MS1, MS2, and MS3, a charging capacitor C0, and capacitors C1, C2, and C3. Switch SW is provided between charging capacitor C0 and the primary side of transformer TC. Switch SW is a semiconductor switching element such as an IGBT (Insulated Gate Bipolar Transistor).

[0126] Magnetic switch MS1 is installed between the secondary side of transformer TC and capacitor C1. Magnetic switch MS2 is installed between capacitor C1 and capacitor C2. Magnetic switch MS3 is installed between capacitor C2 and capacitor C3. The primary and secondary sides of transformer TC are electrically isolated. Furthermore, the winding directions of transformer TC are opposite on the primary and secondary sides.

[0127] The main discharge section 20 and the preionization discharge section 35 are connected in parallel with the PPM 12. The preionization discharge section 35 includes a first preionization discharge section 35a and a second preionization discharge section 35b. The first preionization discharge section 35a and the second preionization discharge section 35b are connected in series between the cathode electrode 20a and the anode electrode 20b. The first preionization discharge section 35a comprises a first dielectric tube 23a, a first preionization electrode 24a, and a first preionization outer electrode 28a. The second preionization discharge section 35b comprises a second dielectric tube 23b, a second preionization electrode 24b, and a second preionization outer electrode 28b.

[0128] The first preionization outer electrode 28a and the second preionization outer electrode 28b constitute the preionization outer electrode. The first preionization outer electrode 28a is connected to the cathode electrode 20a via the inductor L0. The second preionization outer electrode 28b is electrically connected to the anode electrode 20b. The first preionization outer electrode 28a is arranged side by side with the first dielectric tube 23a. The second preionization outer electrode 28b is arranged side by side with the second dielectric tube 23b.

[0129] 1.2.2 Action

[0130] Next, the operation of the charger 11 and the PPM 12 will be described. The charger 11 has a charging voltage set by the laser control processor 14 and charges the charging capacitor C0 based on the set charging voltage.

[0131] In the PPM 12 , when a control signal is sent from the laser control processor 14 to the switch SW, the switch SW is closed, and current flows from the charging capacitor C0 to the primary side of the transformer TC.

[0132] In transformer TC, current flows through the primary side of transformer TC, causing current to flow in the opposite direction through the secondary side of transformer TC due to electromagnetic induction. The electromotive force generated by the current flowing through the secondary side of transformer TC closes magnetic switch MS1, causing current to flow from the secondary side of transformer TC to capacitor C1, charging capacitor C1.

[0133] As capacitor C1 is charged, magnetic switch MS2 is closed, and current flows from capacitor C1 to capacitor C2, charging capacitor C2. At this time, capacitor C2 is charged with a pulse width smaller than the pulse width of the current when charging capacitor C1.

[0134] As capacitor C2 is charged, magnetic switch MS3 is closed, and current flows from capacitor C2 to capacitor C3, charging capacitor C3. At this time, capacitor C3 is charged with a pulse width smaller than the pulse width of the current when charging capacitor C2.

[0135] In this way, as the current flows through the capacitor C1, the capacitor C2, and the capacitor C3 in sequence, the pulse width of the current is compressed, and the charge is charged into the capacitor C3.

[0136] Next, a voltage is applied from capacitor C3 to the pre-ionization discharge section 35. The voltage applied to the pre-ionization discharge section 35 is divided and applied to the first pre-ionization discharge section 35a and the second pre-ionization discharge section 35b. This generates corona discharge in each of the first pre-ionization discharge section 35a and the second pre-ionization discharge section 35b, generating ultraviolet light. Furthermore, a voltage is applied from capacitor C3 to the main discharge section 20, generating a main discharge.

[0137] 1.3 Topics

[0138] like Figure 6 As shown, in the laser chamber device 3 of the comparative example, a first dielectric tube 23a and a second dielectric tube 23b are provided in parallel with the cathode electrode 20a and the anode electrode 20b, respectively. Ultraviolet light generated in the ultraviolet light generating region R1 of the first dielectric tube 23a irradiates the surface of the adjacent cathode electrode 20a as indicated by arrow B1, and also irradiates the surface of the anode electrode 20b, which is diagonally opposite, as indicated by arrow B2. Similarly, ultraviolet light generated in the ultraviolet light generating region R2 of the second dielectric tube 23b irradiates the surface of the adjacent anode electrode 20b as indicated by arrow B3, and also irradiates the surface of the cathode electrode 20a, which is diagonally opposite, as indicated by arrow B4.

[0139] When the distance between the first dielectric tube 23a and the cathode electrode 20a is short, the amount of ultraviolet light (as indicated by arrow B1) blocked by the side surfaces of the cathode electrode 20a increases. Similarly, when the distance between the second dielectric tube 23b and the anode electrode 20b is short, the amount of ultraviolet light (as indicated by arrow B3) blocked by the side surfaces of the anode electrode 20b increases. To reduce the amount of light blocked by the side surfaces of adjacent electrodes, the first dielectric tube 23a and the second dielectric tube 23b need to be positioned a certain distance from the cathode electrode 20a and the anode electrode 20b, respectively.

[0140] The first dielectric tube 23a is held by a pair of first dielectric tube holders 30a and is disposed at a predetermined distance from the cathode electrode 20a. The second dielectric tube 23b is held by a pair of second dielectric tube holders 30b and is disposed at a predetermined distance from the anode electrode 20b.

[0141] However, the pair of first dielectric tube holders 30a and the pair of second dielectric tube holders 30b each consist of multiple components. Even if the components have the same shape, their dimensions vary within tolerances, resulting in positional deviations corresponding to the number of components. Specifically, the first dielectric tube 23a is held by the six components that make up the pair of first dielectric tube holders 30a. The second dielectric tube holder 30b is held by the six components that make up the pair of second dielectric tube holders 30b. Consequently, positional deviations occur in each of the first and second dielectric tube holders 30a, 30b due to the tolerances of the six components.

[0142] In particular, the greater the number of components, the greater the positional offset between the cathode electrode 20a and the diagonally opposed ultraviolet light generating region R2, and the greater the positional offset between the anode electrode 20b and the diagonally opposed ultraviolet light generating region R1. This positional offset increases with the distance between the cathode electrode 20a and the second dielectric tube 23b, and the distance between the anode electrode 20b and the first dielectric tube 23a. Increased positional offset reduces the uniformity of the ultraviolet light intensity irradiating the discharge space 27, leading to variations in the preionization of the laser gas and a deterioration in the intensity distribution characteristics of the pulsed laser light PL.

[0143] In order to solve such a problem, it is required to position the first dielectric tube 23 a and the second dielectric tube 23 b with respect to the cathode electrode 20 a and the anode electrode 20 b with high precision.

[0144] 2. First Implementation

[0145] 2.1 Structure and Action

[0146] A first embodiment of the present disclosure will be described. Figure 7 This is a side view schematically showing the structure of the gas laser device 2 according to the first embodiment. The structure of the gas laser device 2 according to this embodiment is the same as that of the gas laser device 2 according to the comparative example, except for the structure of the laser chamber device 3 .

[0147] The laser chamber apparatus 3 of this embodiment includes first and second insulating holders 40a and 40b instead of the pair of first and second dielectric tube holders 30a and 30b. The other structures of the laser chamber apparatus 3 of this embodiment are the same as those of the comparative example.

[0148] The first insulating holder 40a holds one end of each of the first and second dielectric tubes 23a and 23b. The second insulating holder 40b holds the other ends of each of the first and second dielectric tubes 23a and 23b. In this embodiment, the first and second insulating holders 40a and 40b are disposed on the ground plate 21. In this embodiment, the ground plate 21 corresponds to the "conductive holder" in the technology disclosed herein.

[0149] Next, use Figures 8 to 12 The structures of the first insulating holder 40a and the second insulating holder 40b will be described. Figure 8 It is a cross-sectional view showing the structure of the laser chamber device 3 according to the first embodiment. Figure 9 This is a diagram of the laser cavity device 3 according to the first embodiment as viewed from the output coupling mirror 16 side. Figure 10 This is a diagram of the laser chamber device 3 according to the first embodiment as viewed from the bandwidth narrowing module 15 side. Figure 11 This is a perspective view of the first insulating holder 40a as viewed from one side. Figure 12 This is a perspective view of the first insulating member 40a as viewed from the other side. Figure 8 Shown along Figure 9 The cross section of line AA.

[0150] like Figure 8 As shown, the first insulating holder 40a has holes 41a and 42a formed on one surface and a groove 43a formed on the other surface. The holes 41a and 42a are separated in the Y direction and communicate with the groove 43a extending in the Y direction.

[0151] The second insulating retainer 40b has the same structure as the first insulating retainer 40a. Specifically, the second insulating retainer 40b has holes 41b and 42b formed on one surface and a groove 43b formed on the other surface. The diameters of the holes 41a and 41b are approximately the same as the diameter of the first dielectric tube 23a. The diameters of the holes 42a and 42b are approximately the same as the diameter of the second dielectric tube 23b. The holes 41b and 42b are separated in the Y direction and communicate with the groove 43b extending in the Y direction.

[0152] The first insulating retainer 40a and the second insulating retainer 40b are monolithic, single-piece components. For example, the first insulating retainer 40a and the second insulating retainer 40b are each formed by cutting. The first insulating retainer 40a and the second insulating retainer 40b are preferably made of a material that is highly insulating and resistant to fluorine reaction, such as ceramics such as alumina and zirconia.

[0153] One end of the first dielectric tube 23a fits into the hole 41a of the first insulating holder 40a, while the other end fits into the hole 41b of the second insulating holder 40b. One end of the second dielectric tube 23b fits into the hole 42a of the first insulating holder 40a, while the other end fits into the hole 42b of the second insulating holder 40b. The first and second dielectric tubes 23a and 23b are preferably made of a material with high insulation properties and low reactivity with fluorine, such as ceramics such as alumina or sapphire.

[0154] Steps are formed inside the holes of the first and second insulating holders 40 a and 40 b , and the first and second dielectric tubes 23 a and 23 b are positioned in the Z direction by having their end surfaces abut against the steps.

[0155] A portion of the preionization inner electrode 24, namely, the connecting portion 24c extending in the Y direction between the first preionization electrode 24a and the second preionization electrode 24b, is inserted into the groove 43a of the first insulating holder 40a. In this embodiment, the second insulating holder 40b has the same structure as the first insulating holder 40a. Therefore, while the groove 43b is formed in the second insulating holder 40b, it is not necessary to form the groove 43b. In other words, the second insulating holder 40b only needs to have the holes 41b and 42b.

[0156] like Figure 9 As shown in FIG. 4 , an opening 44 a for passing the pulse laser light PL is formed in the first insulating holder 40 a. Figure 10 As shown, the second insulating holder 40b has an opening 44b formed therein for passing the pulsed laser light PL. As in the comparative example, the first dielectric tube 23a and the second dielectric tube 23b are positioned upstream of the cathode electrode 20a and the anode electrode 20b in terms of the laser gas flow. Alternatively, the first dielectric tube 23a and the second dielectric tube 23b may be positioned downstream of the cathode electrode 20a and the anode electrode 20b in terms of the laser gas flow.

[0157] Figure 13 This diagram shows the connection between the ground plate 21 of the first embodiment and a pair of conductive retaining frames 22. The ground plate 21 extends in the Z direction, which is the lengthwise direction of the cathode electrode 20a and the anode electrode 20b. Protrusions 21a are provided at both ends of the extension direction. The ground plate 21 is connected to the pair of conductive retaining frames 22 via the pair of protrusions 21a.

[0158] The first insulating holder 40a and the second insulating holder 40b are arranged at both ends of the ground plate 21 in the extending direction. Figure 13, the arrangement region S1 indicates the area where the first insulating holder 40a is arranged, and the arrangement region S2 indicates the area where the second insulating holder 40b is arranged. The first insulating holder 40a and the second insulating holder 40b are each screwed to the ground plate 21.

[0159] The operation of the gas laser device 2 of this embodiment is the same as the operation of the gas laser device 2 of the comparative example.

[0160] 2.2 Effect

[0161] According to this embodiment, the first and second dielectric tubes 23a and 23b are held by the first and second insulating holders 40a and 40b, reducing the number of components and thereby suppressing positional deviations due to tolerances. Therefore, according to this embodiment, the first and second dielectric tubes 23a and 23b can be positioned with high precision relative to the cathode electrode 20a and the anode electrode 20b.

[0162] This suppresses positional deviation between cathode electrode 20a and the ultraviolet light generating region obliquely opposite thereto, and between anode electrode 20b and the ultraviolet light generating region obliquely opposite thereto. Consequently, by improving the uniformity of the amount of ultraviolet light irradiating discharge space 27, variations in preionization of the laser gas are suppressed, thereby improving the intensity distribution characteristics of the pulsed laser light PL.

[0163] Furthermore, in the comparative example, the first and second dielectric tubes 23a and 23b are held by line contact with the pair of first and second dielectric tube holding portions 30a and 30b. In contrast, in this embodiment, the first and second dielectric tubes 23a and 23b are held by surface contact by fitting into the holes 41a and 42a of the first insulating holder 40a and the holes 41b and 42b of the second insulating holder 40b. This allows for more precise positioning of the first and second dielectric tubes 23a and 23b.

[0164] Furthermore, if the first dielectric tube 23a and the second dielectric tube 23b are made of the same material, diameter, length, etc., variations in the voltage applied thereto can be suppressed. This further improves the uniformity of the amount of ultraviolet light irradiating the discharge space 27, thereby further improving the intensity distribution characteristics of the pulsed laser light PL.

[0165] 2.3 Variations

[0166] Hereinafter, modifications of the first embodiment will be described. Each of the following modifications differs from the first embodiment only in the structure of the laser chamber device 3 .

[0167] 2.3.1 First Modification

[0168] Figure 14 It is a cross-sectional view showing the structure of a laser chamber device 3 according to a first modification of the first embodiment. Figure 15 This is a diagram of the laser cavity device 3 according to the first modified example of the first embodiment as viewed from the output coupling mirror 16 side. Figure 16 This is a diagram of the laser cavity device 3 according to the first modification of the first embodiment as viewed from the side of the narrowband module 15. Figure 14 Shown along Figure 15 The cross section of line AA.

[0169] In this variation, the first insulating retainer 40a and the second insulating retainer 40b are mounted on the base portion 20c of the anode electrode 20b. The anode electrode 20b and the base portion 20c are a single, integral structure. For example, the anode electrode 20b and the base portion 20c are formed by cutting a metal part.

[0170] Similar to the ground plate 21 of the first embodiment, the base portion 20c extends in the Z direction and is connected to a pair of conductive retaining frames 22 via protrusions provided at both ends of the extension direction. A first insulating retainer 40a and a second insulating retainer 40b are disposed at both ends of the base portion 20c in the extension direction. In this variation, the base portion 20c corresponds to the "conductive retainer" in the disclosed technology.

[0171] The laser chamber apparatus 3 of this modification has the same structure as the laser chamber apparatus 3 of the first embodiment, except that a base portion 20 c having an anode electrode 20 b is provided instead of the ground plate 21 .

[0172] In this modified example, first and second insulating holders 40a, 40b are disposed on base portion 20c, which is integral with anode electrode 20b, instead of ground plate 21. This eliminates dimensional errors caused by tolerances in ground plate 21. This allows for more precise positioning of first and second dielectric tubes 23a, 23b, further improving the intensity distribution characteristics of pulsed laser light PL.

[0173] 2.3.2 Second Modification

[0174] Figure 17 This is a diagram showing a laser cavity device 3 according to a second modified example of the first embodiment as viewed from the output coupling mirror 16 side. Figure 18 This is a diagram showing a laser chamber device 3 according to a second modified example of the first embodiment as viewed from the side of the bandwidth narrowing module 15 .

[0175] In this variation, in addition to the first and second dielectric tubes 23a and 23b, a third and fourth dielectric tubes 23c and 23d are provided within the chamber 10. The third and fourth dielectric tubes 23c and 23d have the same structure as the first and second dielectric tubes 23a and 23b, and are provided side by side with the cathode electrode 20a and the anode electrode 20b.

[0176] In this modification, the first and second dielectric tubes 23a and 23b are positioned upstream of the cathode and anode electrodes 20a and 20b, respectively, and the third and fourth dielectric tubes 23c and 23d are positioned downstream of the cathode and anode electrodes 20a and 20b, respectively.

[0177] like Figure 17 As shown, in this modified example, holes 45a and 46a are formed on one surface of the first insulating holder 40a in addition to holes 41a and 42a, and a groove 47a is formed on the other surface in addition to groove 43a. The structures of holes 45a, 46a and groove 47a are the same as those of holes 41a, 42a and groove 43a, respectively.

[0178] like Figure 18 As shown, in this modified example, holes 45b and 46b are formed on one surface of the second insulating retainer 40b in addition to holes 41b and 42b, and a groove 47b is formed on the other surface in addition to groove 43b. The structures of holes 45b, 46b and groove 47b are the same as those of holes 41b, 42b and groove 43b, respectively.

[0179] One end of the third dielectric tube 23c is fitted into the hole 45a of the first insulating holder 40a, and the other end of the third dielectric tube 23c is fitted into the hole 45b of the second insulating holder 40b. One end of the fourth dielectric tube 23d is fitted into the hole 46a of the first insulating holder 40a, and the other end of the fourth dielectric tube 23d is fitted into the hole 46b of the second insulating holder 40b.

[0180] A portion of the preionization inner electrode 50 is inserted into the groove 47a of the first insulating holder 40a. The preionization inner electrode 50 has the same structure as the preionization inner electrode 24, and includes a third preionization electrode 50a disposed within the interior of the third dielectric tube 23c and a fourth preionization electrode 50b disposed within the interior of the fourth dielectric tube 23d. The third and fourth preionization electrodes 50a and 50b are connected at the same end. The connection portion between the third and fourth preionization electrodes 50a and 50b, extending in the Y direction, is inserted into the groove 47a.

[0181] In this variation, four dielectric tubes are provided. Similar to the first embodiment, these four dielectric tubes are held by a first insulating holder 40a and a second insulating holder 40b, thus minimizing the number of components. Consequently, even downstream of the laser gas, positional deviation between the cathode electrode 20a and the diagonally opposed ultraviolet light generating region, as well as between the anode electrode 20b and the diagonally opposed ultraviolet light generating region, can be suppressed. Thus, according to this variation, even with the provision of four dielectric tubes, the intensity distribution characteristics of the pulsed laser PL are not degraded.

[0182] Furthermore, this modification can also be applied to the laser cavity device 3 of the first modification. That is, four dielectric tubes can also be provided in the laser cavity device 3 of the first modification.

[0183] 3. Second Implementation

[0184] 3.1 Structure and Action

[0185] A second embodiment of the present disclosure will be described. The structure of the gas laser device 2 of the second embodiment is the same as that of the gas laser device 2 of the first embodiment, except for the structure of the laser chamber device 3 .

[0186] Figure 19 It is a cross-sectional view showing the structure of a laser chamber device 3 according to the second embodiment. Figure 20 This is a diagram of the laser cavity device 3 according to the second embodiment as viewed from the output coupling mirror 16 side. Figure 21 This is a diagram of the laser cavity device 3 according to the second embodiment as viewed from the side of the narrowband module 15. Figure 19 Shown along Figure 20 The cross section of line AA.

[0187] In this embodiment, the first insulating holder 40a and the second insulating holder 40b are held by a pair of conductive holding frames 22. Figure 19 and Figure 20 As shown, each of the pair of conductive retaining frames 22 has a recessed portion 22a. The first and second insulating retaining members 40a, 40b are positioned so that their bottoms fit into the recessed portions 22a. The first and second insulating retaining members 40a, 40b have the same structure as in the first embodiment. In this embodiment, the conductive retaining frames 22 and the grounding plate 21 correspond to the "conductive retaining members" in the disclosed technology.

[0188] Figure 22This figure shows the connection between a ground plate 21 and a pair of conductive holding frames 22 according to the second embodiment. In this embodiment, two protrusions 21b are provided on each end face of the ground plate 21 in the direction in which it extends. Grooves 22b, which engage with the protrusions 21b, are provided on either side of a recess 22a in the conductive holding frames 22. The ground plate 21 is connected to the conductive holding frames 22 by fitting the two protrusions 21b into the two grooves 22b.

[0189] like Figures 20 to 22 As shown, recess 22a intersects an imaginary YZ plane passing through anode electrode 20b in the X direction. Furthermore, the bottom surface of recess 22a is not limited to a flat surface and may be curved into an arched shape. In this case, the bottom surfaces of first insulating holder 40a and second insulating holder 40b can be curved into an arched shape to fit within recess 22a.

[0190] The operation of the gas laser device 2 of this embodiment is the same as the operation of the gas laser device 2 of the comparative example.

[0191] 3.2 Effect

[0192] In this embodiment, the recesses 22a formed in the pair of conductive holding frames 22 are formed to intersect with the imaginary YZ plane passing through the anode electrode 20b in the X direction. Therefore, simply by fitting the first insulating holder 40a and the second insulating holder 40b into the recesses 22a, the first dielectric tube 23a and the second dielectric tube 23b can be positioned with high precision relative to the cathode electrode 20a and the anode electrode 20b.

[0193] In this embodiment, the first insulating holder 40a and the second insulating holder 40b are held by a pair of conductive holding frames 22. Therefore, in this embodiment, the first insulating holder 40a and the second insulating holder 40b can be positioned at a distance from the cathode electrode 20a and the anode electrode 20b, respectively, compared to the first embodiment. In other words, in this embodiment, the length of the first dielectric tube 23a and the second dielectric tube 23b can be made longer than the length of the cathode electrode 20a and the anode electrode 20b.

[0194] Thus, even when the first insulating holder 40a and the second insulating holder 40b are disposed at positions away from the cathode electrode 20a and the anode electrode 20b, the configuration of this embodiment enables high-precision positioning, thereby preventing deterioration in the intensity distribution characteristics of the pulsed laser light PL.

[0195] Furthermore, according to this embodiment, the lengths of the first dielectric tube 23a and the second dielectric tube 23b can be lengthened. Figure 19The pre-ionization of the laser gas in the discharge region E at the end portions of the cathode electrode 20 a and the anode electrode 20 b is stabilized.

[0196] 3.3 Variations

[0197] Hereinafter, modifications of the second embodiment will be described. Each of the following modifications differs from the second embodiment only in the structure of the laser chamber device 3 .

[0198] 3.3.1 First Modification

[0199] Figure 23 It is a cross-sectional view showing the structure of a laser chamber device 3 according to a first modified example of the second embodiment. Figure 24 This is a diagram showing the laser cavity device 3 according to the first modified example of the second embodiment as viewed from the output coupling mirror 16 side. Figure 25 This is a diagram of the laser cavity device 3 according to the first modified example of the second embodiment as viewed from the side of the narrowband module 15. Figure 23 Shown along Figure 24 The cross section of line AA.

[0200] The laser chamber apparatus 3 of this modification has the same structure as the laser chamber apparatus 3 of the second embodiment, except that a base portion 20c having an anode electrode 20b is provided in place of the ground plate 21. As in the first modification of the first embodiment, the anode electrode 20b and the base portion 20c are a single, integral structure.

[0201] In this variation, similar to the second embodiment, first and second insulating retainers 40a, 40b are retained by a pair of conductive retaining frames 22. Specifically, first and second insulating retainers 40a, 40b are each fitted into recessed portions 22a of conductive retaining frames 22. Furthermore, in this variation, conductive retaining frames 22 and base 20c correspond to the "conductive retainers" in the disclosed technology.

[0202] The base portion 20c is similar to the ground plate 21 of the second embodiment, and has two protrusions 20d on each end surface in the extending direction. The base portion 20c is connected to the conductive holding frame 22 by fitting the two protrusions 20d into the two grooves 22b.

[0203] In this modification, since the ground plate 21 is not provided, dimensional errors caused by the tolerance of the ground plate 21 are eliminated. This allows the first dielectric tube 23a and the second dielectric tube 23b to be positioned with higher precision, further improving the intensity distribution characteristics of the pulsed laser PL.

[0204] 3.3.2 Second Modification

[0205] Figure 26This is a diagram showing a laser cavity device 3 according to a second modified example of the second embodiment as viewed from the output coupling mirror 16 side. Figure 27 This is a diagram showing a laser chamber device 3 according to a second modified example of the second embodiment as viewed from the side of the bandwidth narrowing module 15 .

[0206] In this modification, in addition to the first and second dielectric tubes 23a and 23b, third and fourth dielectric tubes 23c and 23d are provided inside the chamber 10. The structures of the third and fourth dielectric tubes 23c and 23d are the same as those in the second modification of the first embodiment.

[0207] In this variation, holes 45a and 46a are formed on one surface of the first insulating retainer 40a in addition to holes 41a and 42a, and groove 47a is formed on the other surface in addition to groove 43a. Holes 45b and 46b are formed on one surface of the second insulating retainer 40b in addition to holes 41b and 42b, and groove 47b is formed on the other surface in addition to groove 43b. The structures of the first and second insulating retainers 40a and 40b are the same as those of the second variation of the first embodiment.

[0208] This variation can achieve the same effects as the second variation of the first embodiment. Furthermore, this variation can also be applied to the laser chamber apparatus 3 of the first variation of the second embodiment. Specifically, the laser chamber apparatus 3 of the first variation of the second embodiment can also be provided with four dielectric tubes.

[0209] 4. Third Implementation

[0210] Next, an embodiment capable of suppressing abnormal discharge will be described. Figure 28 As shown, in the laser chamber device 3 of the second embodiment, when the pressure of the laser gas in the chamber 10 is increased to increase the laser output, abnormal discharge may occur during the pre-ionization process. Specifically, abnormal discharge occurs between the pre-ionization inner electrode 24 and the surrounding metal components with a potential difference. For example, Figure 28 As shown in the path P, current flows from the preionization inner electrode 24 along the surfaces of the first insulating holder 40a and the second insulating holder 40b toward the ground plate 21 or the chamber 10, thereby generating abnormal discharge. Such discharge is called creeping discharge.

[0211] When abnormal discharge occurs, the potential difference between the preionization inner electrode 24 and the preionization outer electrode changes, thereby causing deviation in the preionization of the laser gas in the discharge space 27 and deteriorating the intensity distribution characteristics of the pulsed laser PL. Such abnormal discharge can be caused by expanding Figure 28 The length of the path P shown, that is, the creepage distance, is suppressed.

[0212] 4.1 Structure and Action

[0213] A third embodiment of the present disclosure will be described. The structure of the gas laser device 2 of the third embodiment is the same as that of the gas laser device 2 of the first embodiment, except for the structure of the laser chamber device 3 .

[0214] Figure 29 This is a cross-sectional view showing the structure of a laser chamber apparatus 3 according to a third embodiment. The laser chamber apparatus 3 according to this embodiment has the same structure as the laser chamber apparatus 3 according to the second embodiment, except for the structures of the first insulating holder 40a and the second insulating holder 40b.

[0215] In this embodiment, the first insulating member 40a has a surface with a concavo-convex structure 48a. Similarly, the second insulating member 40b has a surface with a concavo-convex structure 48b. Specifically, the concavo-convex structure 48a is formed on the inner surface of the groove 43a. The concavo-convex structure 48b is formed on the inner surface of the groove 43b.

[0216] Figure 30 This is a cross-sectional view of the first insulating holder 40a cut along the groove 43a. The concavo-convex structure 48a is formed so that the inner surface of the groove 43a is concavo-convex in the Z direction. This increases the creepage distance. The concavo-convex structure 48b has the same structure.

[0217] The concavo-convex structure 48a may be formed on the surface of the first insulating member 40a other than the inner surface of the groove 43a. Similarly, the concavo-convex structure 48b may be formed on the surface of the second insulating member 40b other than the inner surface of the groove 43b.

[0218] The operation of the gas laser device 2 of this embodiment is the same as the operation of the gas laser device 2 of the comparative example.

[0219] 4.2 Effect

[0220] According to this embodiment, since the creeping distance is increased, abnormal discharge can be suppressed even when the pressure of the laser gas is increased. As a result, high-power pulsed laser light PL can be output without deteriorating the intensity distribution.

[0221] 4.3 Variations

[0222] Hereinafter, modifications of the third embodiment will be described. Each of the following modifications differs from the third embodiment only in the configuration of the first insulating holder 40 a and the second insulating holder 40 b .

[0223] 4.3.1 First Modification

[0224] Figure 31 This is a cross-sectional view showing the structure of a laser chamber apparatus 3 according to a first variation of the third embodiment. In this variation, the first insulating holder 40a is composed of a main body 60a and extensions 61a and 62a. Similarly, the second insulating holder 40b is composed of a main body 60b and extensions 61b and 62b.

[0225] The main body 60a has the same structure as the first insulating retainer 40a of the first embodiment. Furthermore, similar to the third embodiment, the groove 43a of the main body 60a may be provided with a concavo-convex structure 48a. Similarly, the main body 60b has the same structure as the second insulating retainer 40b of the first embodiment. Furthermore, similar to the third embodiment, the groove 43b of the main body 60b may be provided with a concavo-convex structure 48b.

[0226] Figure 32 This is a perspective view showing the structure of the first insulating retainer 40a according to the third embodiment. Extensions 61a and 62a extend from the outer periphery of the main body 60a in the Z direction. Extension 61a extends from the main body 60a in one direction, while extension 62a extends in the other direction. The main body 60a and extensions 61a and 62a may also be an integral structure. The structure of the second insulating retainer 40b is the same as that of the first insulating retainer 40a.

[0227] In this modification, the first insulating holder 40a and the second insulating holder 40b include the extensions 61a and 62a and the extensions 61b and 62b, respectively, so that the creepage distance is increased.

[0228] 4.3.2 Second Modification

[0229] Figure 33 This is a cross-sectional view illustrating the structure of a laser chamber apparatus 3 according to a second variation of the third embodiment. In this variation, an insulating cover 70a is attached to the first insulating holder 40a, covering a portion of the surface of the first insulating holder 40a. Similarly, an insulating cover 70b is attached to the second insulating holder 40b, covering a portion of the surface of the second insulating holder 40b. Covers 70a and 70b are attached to the region encompassing the aforementioned abnormal discharge path P. Covers 70a and 70b are preferably made of a ceramic, such as alumina, which has high insulating properties.

[0230] The structures of the first insulating holder 40a and the second insulating holder 40b are the same as those in the first embodiment. In addition, similarly to the third embodiment, the grooves 43a and 43b may be provided with concavo-convex structures 48a and 48b, respectively.

[0231] Figure 341 is a perspective view showing the structure of the cover 70a. The cover 70a is configured to cover the side surfaces and the upper surface of the first insulating holder 40a facing the chamber 10. The cover 70a has an opening 72a for passing the pulsed laser light PL.

[0232] Furthermore, a concavo-convex structure 71a is formed on the inner surface of the upper portion of cover 70a, where abnormal discharge is more likely to occur. Concavo-convex structure 71a is formed by making a portion of the inner surface of the upper portion of cover 70a concavo-convex in the Z direction. Furthermore, concavo-convex structure 71a is not limited to being formed on the inner surface of the upper portion of cover 70a; it can also be formed on other surfaces of cover 70a. Cover 70b has the same structure as cover 70a.

[0233] In this modification, covers 70a and 70b are attached to the first insulating holder 40a and the second insulating holder 40b, respectively, so that the creepage distance is increased. This can achieve the same effects as those of the third embodiment.

[0234] 4.3.3 Third Modification

[0235] In the third embodiment and its modifications, abnormal discharge is suppressed by increasing the creeping distance. However, a portion of the pre-ionization internal electrode 24 where abnormal discharge is likely to occur may be covered with an insulating material.

[0236] Figure 35 This is a cross-sectional view showing a portion of the first insulating holder 40a. In this variation, the corners of the preionization inner electrode 24 are covered with a cylindrical insulator 80. Specifically, the ends of the first preionization electrode 24a and the second preionization electrode 24b are covered with the insulator 80. The insulator 80 is preferably made of a ceramic such as alumina, which has high insulating properties.

[0237] Furthermore, the insulator 80 has a nested structure. At the end of the first pre-ionization electrode 24a, a portion of the insulator 80 is inserted between the first pre-ionization electrode 24a and the first dielectric tube 23a. Furthermore, at the end of the second pre-ionization electrode 24b, a portion of the insulator 80 is inserted between the second pre-ionization electrode 24b and the second dielectric tube 23b.

[0238] In this modification, since the portion of the pre-ionization inner electrode 24 where abnormal discharge is likely to occur is covered with the insulator 80 , the abnormal discharge can be suppressed.

[0239] The structure for suppressing abnormal discharge described in the third embodiment and each modified example of the third embodiment is also applicable to the first embodiment, each modified example of the first embodiment, and each modified example of the second embodiment.

[0240] 5. Other variations

[0241] In the above-described embodiments and variations, the first dielectric tube 23a and the second dielectric tube 23b are positioned in the Z direction by having their end surfaces abut against steps within the holes of the first insulating holder 40a and the second insulating holder 40b, respectively. Alternatively, steps may be provided at the ends of the first dielectric tube 23a and the second dielectric tube 23b, and the steps may abut against the corners of the holes, thereby achieving positioning in the Z direction.

[0242] Figure 36 This is a cross-sectional view showing a portion of the first insulating holder 40a. In this variation, a step 90 is formed at the end of the first dielectric tube 23a. In this variation, no step is formed inside the hole 41a. The first dielectric tube 23a is positioned in the Z direction by the contact of the step 90 with the corner of the hole 41a. The second insulating holder 40b and the second dielectric tube 23b have the same structure.

[0243] In the above-described embodiments and modifications, an excimer laser device is exemplified as the gas laser device 2 . However, the gas laser device 2 may be an F 2 laser device or the like using a laser gas containing fluorine gas and a buffer gas.

[0244] 6. Method for manufacturing electronic devices

[0245] Figure 37 This figure schematically illustrates an example configuration of an exposure apparatus 100. Exposure apparatus 100 includes an illumination system 104 and a projection system 106. Illumination system 104 illuminates the reticle pattern of a mask (not shown) positioned on reticle stage RT using pulsed laser light PL incident from, for example, a gas laser device 2. Projection system 106 reduces and projects the pulsed laser light PL transmitted through the reticle, forming an image on a workpiece (not shown) positioned on workpiece stage WT. The workpiece is a photosensitive substrate such as a semiconductor wafer coated with photoresist.

[0246] Exposure apparatus 100 synchronously moves reticle stage RT and workpiece stage WT in parallel, exposing a workpiece to pulsed laser light PL reflecting the reticle pattern. After the reticle pattern is transferred to a semiconductor wafer through the aforementioned exposure process, semiconductor devices can be manufactured through multiple steps. Semiconductor devices are an example of "electronic devices" in this disclosure.

[0247] Furthermore, the gas laser device 2 is not limited to the manufacture of electronic devices, but can also be used for laser processing such as hole drilling.

[0248] The above description is intended to be illustrative rather than limiting, and therefore, it will be apparent to those skilled in the art that modifications may be made to the various embodiments of the present disclosure without departing from the scope of the appended claims.

[0249] The terms used in this specification and the appended claims should be interpreted as "non-limiting" terms. For example, the terms "include" or "comprise" should be interpreted as "not limited to the parts recorded as included". The term "have" should be interpreted as "not limited to the parts recorded as having". In addition, the phrase "one" recorded in this specification and the appended claims should be interpreted as "at least one" or "one or more". In addition, the phrases "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 to include combinations of them with contents other than "A", "B" and "C".

Claims

1. A laser chamber device that generates laser light by exciting a pre-ionized laser gas through discharge, wherein: The laser chamber device comprises: a chamber containing laser gas; a first discharge electrode disposed inside the chamber; a second discharge electrode disposed inside the chamber so as to face the first discharge electrode and configured to discharge and excite the laser gas together with the first discharge electrode; a conductive holding member that holds the first discharge electrode; a first dielectric tube disposed along the first discharge electrode; a second dielectric tube, which is opposite to the first dielectric tube and is arranged along the second discharge electrode; a first pre-ionization electrode disposed in the interior space of the first dielectric tube; a second pre-ionization electrode disposed in the interior space of the second dielectric tube; a first insulating holder disposed on the conductive holder and holding one end portion of each of the first dielectric tube and the second dielectric tube; and The second insulating holder is disposed on the conductive holder and holds the other end portions of the first dielectric tube and the second dielectric tube.

2. The laser chamber device according to claim 1, wherein: The first pre-ionization electrode is connected to the second pre-ionization electrode.

3. The laser chamber device according to claim 2, wherein: A groove is formed in the first insulating holder. A connection portion between the first pre-ionization electrode and the second pre-ionization electrode is disposed in the tank.

4. The laser chamber device according to claim 1, wherein: The first insulating holder is made of ceramic.

5. The laser chamber device according to claim 4, wherein: The ceramic is aluminum oxide or zirconium oxide.

6. The laser chamber device according to claim 1, wherein: The first dielectric tube and the second dielectric tube are made of aluminum oxide or sapphire.

7. The laser chamber device according to claim 1, wherein: An end portion of the first dielectric tube and an end portion of the second dielectric tube are respectively fitted into the first insulating holder.

8. The laser chamber device according to claim 7, wherein: The first insulating holder has two holes. An end portion of the first dielectric tube is fitted into one of the two holes, and an end portion of the second dielectric tube is fitted into the other of the two holes.

9. The laser chamber device according to claim 1, wherein: The conductive holding member extends along the length direction of the first discharge electrode. The first insulating holder and the second insulating holder are arranged at both ends of the conductive holder in the extending direction.

10. The laser chamber device according to claim 1, wherein: The conductive holder serves as a base portion of the first discharge electrode.

11. The laser chamber device according to claim 1, wherein: The laser chamber device further comprises: A third dielectric tube having a third pre-ionization electrode disposed in its inner space; and a fourth dielectric tube having a fourth pre-ionization electrode disposed in its inner space; The first insulating holder holds one end portion of each of the third dielectric tube and the fourth dielectric tube. The second insulating holder holds the other end portions of the third dielectric tube and the fourth dielectric tube.

12. The laser chamber device according to claim 1, wherein: A step is formed at each end of the first dielectric tube and the second dielectric tube.

13. The laser chamber device according to claim 1, wherein: The first insulating holding member has a concavo-convex structure on a surface.

14. The laser chamber device according to claim 1, wherein: The first insulating holder includes an extension portion extending from an outer periphery.

15. The laser chamber device according to claim 1, wherein: The laser chamber device further includes a cover that covers a portion of a surface of the first insulating holder.

16. The laser chamber device according to claim 15, wherein: The cover has a concavo-convex structure on the surface.

17. The laser chamber device according to claim 1, wherein: The laser chamber device further includes a cylindrical insulator that covers a portion of the first pre-ionization electrode or the second pre-ionization electrode.

18. The laser chamber device according to claim 1, wherein: The first insulating holder and the second insulating holder are each an integral structure.

19. A gas laser device comprising a laser chamber device, wherein the laser chamber device generates laser light by performing discharge excitation on pre-ionized laser gas, wherein: The laser chamber device comprises: a chamber containing laser gas; a first discharge electrode disposed inside the chamber; a second discharge electrode disposed inside the chamber so as to face the first discharge electrode and configured to discharge and excite the laser gas together with the first discharge electrode; a conductive holding member that holds the first discharge electrode; a first dielectric tube disposed along the first discharge electrode; a second dielectric tube, which is opposite to the first dielectric tube and is arranged along the second discharge electrode; a first pre-ionization electrode disposed in the interior space of the first dielectric tube; a second pre-ionization electrode disposed in the interior space of the second dielectric tube; a first insulating holder disposed on the conductive holder and holding one end portion of each of the first dielectric tube and the second dielectric tube; and The second insulating holder is disposed on the conductive holder and holds the other end portions of the first dielectric tube and the second dielectric tube.

20. A method for manufacturing an electronic device, wherein: The manufacturing method of the electronic device comprises the following steps: generating laser light using a gas laser device including a laser chamber device; outputting the laser light to an exposure device; and exposing the laser light on a photosensitive substrate in the exposure device to manufacture an electronic device, The laser chamber device comprises: a chamber containing laser gas; a first discharge electrode disposed inside the chamber; a second discharge electrode disposed inside the chamber so as to face the first discharge electrode and configured to discharge and excite the laser gas together with the first discharge electrode; a conductive holding member that holds the first discharge electrode; a first dielectric tube disposed along the first discharge electrode; a second dielectric tube, which is opposite to the first dielectric tube and is arranged along the second discharge electrode; a first pre-ionization electrode disposed in the interior space of the first dielectric tube; a second pre-ionization electrode disposed in the interior space of the second dielectric tube; a first insulating holder disposed on the conductive holder and holding one end portion of each of the first dielectric tube and the second dielectric tube; and The second insulating holder is disposed on the conductive holder and holds the other end portions of the first dielectric tube and the second dielectric tube.

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