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

Abstract

To provide a laser chamber, a gas laser device, and a manufacturing method for an electronic device, which are capable of improving a flow rate of a laser gas flowing in a discharge space.SOLUTION: A laser chamber according to one aspect of the present disclosure is a laser chamber of a gas laser device that outputs laser light, and includes: a container filled with a laser gas; a first electrode that extends in a first direction and is disposed in the container; a second electrode that extends in the first direction and is disposed at a position closer to an inner wall of the container than the first electrode in a state of facing the first electrode in a second direction orthogonal to the first direction; a fan that causes the laser gas to flow through a discharge space between the first electrode and the second electrode; an insulating guide disposed on a downstream side of the second electrode; and a vortex dividing member that is constituted of a plurality of structures extending in the first direction and discretely disposed along a direction in which the laser gas flows on the downstream side of the insulating guide, and dividing a vortex generated by a part of a flow of the laser gas.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

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

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

[0004] [Patent Document 1] Summary of the specification of U.S. Patent No. 6,442,181

[0005] A laser chamber according to one aspect of the present disclosure is a laser chamber of a gas laser device that outputs laser light, and comprises a container filled with laser gas, a first electrode extending in a first direction and arranged within the container, a second electrode extending in the first direction and facing the first electrode in a second direction perpendicular to the first direction and arranged closer to the inner wall of the container than the first electrode, a fan that flows the laser gas through a discharge space between the first electrode and the second electrode, an insulating guide arranged downstream of the second electrode, and a vortex dividing member that extends in the first direction and is composed of a plurality of structures arranged discretely along the direction in which the laser gas flows, downstream of the insulating guide, and that divides vortices generated by part of the flow of the laser gas.

[0006] A gas laser device according to one aspect of the present disclosure is a gas laser device that outputs laser light and includes an optical resonator and a laser chamber arranged so that the optical path of the optical resonator passes through it, wherein the laser chamber includes a container filled with laser gas, a first electrode extending in a first direction and arranged within the container, a second electrode extending in the first direction and arranged opposite the first electrode in a second direction perpendicular to the first direction and positioned closer to the inner wall of the container than the first electrode, a fan that flows the laser gas through a discharge space between the first electrode and the second electrode, an insulating guide arranged downstream of the second electrode, and a vortex dividing member that extends in the first direction and is composed of a plurality of structures arranged discretely along the direction in which the laser gas flows, downstream of the insulating guide, and that divides vortices generated by part of the flow of the laser gas.

[0007] A method for manufacturing an electronic device according to one aspect of the present disclosure is a gas laser apparatus that outputs laser light and includes an optical resonator and a laser chamber arranged so that an optical path of the optical resonator passes through the gas laser apparatus, wherein the laser chamber includes a container filled with laser gas, a first electrode extending in a first direction and arranged within the container, a second electrode extending in the first direction and arranged opposite the first electrode in a second direction perpendicular to the first direction and positioned closer to the inner wall of the container than the first electrode, a fan that flows the laser gas through a discharge space between the first electrode and the second electrode, an insulating guide arranged downstream of the second electrode, and a vortex dividing member that extends in the first direction and is composed of a plurality of structures arranged discretely along the direction in which the laser gas flows, downstream of the insulating guide, and that divides vortices generated by part of the flow of the laser gas, the gas laser apparatus generating laser light, outputting the laser light to an exposure apparatus, and exposing a photosensitive substrate in the exposure apparatus to the laser light to manufacture an electronic device. [Brief explanation of the drawings]

[0008] Some embodiments of the present disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which: [Figure 1] FIG. 1 is a side view schematically showing the configuration of a gas laser device according to a comparative example. [Figure 2] FIG. 2 is a cross-sectional view schematically showing the configuration of a gas laser device according to a comparative example. [Figure 3] FIG. 3 is a cross-sectional view showing in detail the configuration of the vicinity of the main electrode of the laser chamber. [Figure 4] FIG. 4 is a cross-sectional view showing in detail the configuration in the vicinity of the main electrode of the laser chamber according to the first embodiment. [Figure 5] FIG. 5 is a diagram showing an example of the flow of laser gas in the first embodiment. [Figure 6] FIG. 6 is a cross-sectional view showing in detail the configuration near the main electrode of the laser chamber according to the second embodiment. [Figure 7] FIG. 7 is a diagram showing an example of the flow of laser gas in the second embodiment. [Figure 8]FIG. 8 is a cross-sectional view showing in detail the configuration near the main electrode of the laser chamber according to the third embodiment. [Figure 9] FIG. 9 is a diagram showing an example of the flow of laser gas in the third embodiment. [Figure 10] FIG. 10 is a cross-sectional view showing in detail the configuration near the main electrode of the laser chamber according to the fourth embodiment. [Figure 11] FIG. 11 is a diagram schematically showing an example of the configuration of an exposure apparatus. Embodiment

[0009] <Contents> 1. Comparative Example 1.1 Configuration 1.2 Operation 1.3 Challenges 2. First embodiment 2.1 Configuration 2.2 Operation 2.3 Effects 3. Second embodiment 3.1 Configuration 3.2 Operation 3.3 Effects 4. Third embodiment 4.1 Configuration 4.2 Operation 4.3 Effects 5. Fourth embodiment 5.1 Configuration 5.2 Operation 5.3 Effects 6. Manufacturing method of electronic devices

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

[0011] 1. Comparative Example First, a comparative example of the present disclosure will be described. The comparative example of the present disclosure is a form that the applicant recognizes as being known only by the applicant, and is not a publicly known example that the applicant acknowledges.

[0012] 1.1 Configuration The configuration of a gas laser device 2 according to a comparative example will be described using Figures 1 and 2. Figure 1 shows a schematic configuration of the gas laser device 2. Figure 2 is a cross-sectional view of the gas laser device 2 shown in Figure 1 as seen from the Z direction. The gas laser device 2 is a discharge excitation type gas laser device that discharges and excites laser gas, such as an excimer laser device.

[0013] In FIG. 1, the traveling direction of pulsed laser light PL output from gas laser device 2 is defined as the Z direction. The discharge direction, which will be described later, is defined as the Y direction. The direction perpendicular to the Z direction and the Y direction is defined as the X direction. The pulsed laser light PL is an example of a "laser light" according to the technology of the present disclosure. The Z direction is an example of a "first direction" according to the technology of the present disclosure. The Y direction is an example of a "second direction" according to the technology of the present disclosure. The X direction is an example of a "third direction" according to the technology of the present disclosure.

[0014] 1, the gas laser device 2 includes a laser chamber 10, a charger 11, a pulse power module (PPM) 12, a pulse energy measurement unit 13, a processor 14, a pressure sensor 17, and a laser resonator. The laser resonator is composed of a line narrowing module 15 and an output coupling mirror 16.

[0015] The laser chamber 10 includes a container 10a formed of, for example, aluminum metal with a nickel-plated surface. As shown in Figures 1 and 2, the container 10a is provided therein with a main electrode 20, a ground plate 21, wiring 22, a fan 23, a heat exchanger 24, an insulating guide 28, a conductive guide 29, and a preionization electrode 30. The preionization electrode 30 includes an outer preionization electrode 31, a dielectric pipe 32, and an inner preionization electrode 33.

[0016] The vessel 10a is filled with a laser gas containing fluorine as a laser medium. 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.

[0017] An opening is formed in the container 10a. An electrical insulating plate 26 with a feedthrough 25 embedded therein is attached to the container 10a via an O-ring (not shown) so as to close the opening. The PPM 12 is placed on the electrical insulating plate 26. The container 10a is grounded.

[0018] The PPM 12 includes a charging capacitor (not shown) and is connected to the main electrode 20 via a feedthrough 25. The PPM 12 includes a switch SW for discharging the main electrode 20. The charger 11 is connected to the charging capacitor of the PPM 12. Hereinafter, the discharge occurring at the main electrode 20 will be referred to as the main discharge.

[0019] The main electrode 20 consists of a cathode electrode 20a and an anode electrode 20b. The cathode electrode 20a and the anode electrode 20b are arranged in the container 10a so that their discharge surfaces face each other. The space between the discharge surface of the cathode electrode 20a and the discharge surface of the anode electrode 20b is called a discharge space 27. The cathode electrode 20a and the anode electrode 20b each extend in the Z direction.

[0020] The cathode electrode 20a has a surface opposite to the discharge surface supported by an electrically insulating plate 26 and connected to a feedthrough 25. That is, the cathode electrode 20a faces the anode electrode 20b and is disposed closer to the inner wall 10b of the container 10a than the anode electrode 20b. The anode electrode 20b has a surface opposite to the discharge surface supported by a ground plate 21. The anode electrode 20b is an example of a "first electrode" according to the technology of the present disclosure. The cathode electrode 20a is an example of a "second electrode" according to the technology of the present disclosure.

[0021] The ground plate 21 is connected to the container 10a via wiring 22. The container 10a is connected to the ground. Therefore, the ground plate 21 is connected to the ground via wiring 22. The end of the ground plate 21 in the Z direction is fixed to the container 10a.

[0022] Fan 23 is a cross-flow fan for circulating laser gas within vessel 10a, and is disposed on the opposite side of ground plate 21 from discharge space 27. Motor 23a that rotates fan 23 is connected to vessel 10a.

[0023] The laser gas blown out from fan 23 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 from discharge space 27 is sucked into fan 23 via heat exchanger 24. Heat exchanger 24 changes the temperature of the laser gas by exchanging heat between the laser gas and a refrigerant supplied inside heat exchanger 24.

[0024] Insulating guide 28 is disposed on the surface of electrical insulating plate 26 facing discharge space 27, sandwiching cathode electrode 20a therebetween. Insulating guide 28 is formed in a shape that guides the flow of laser gas so that the laser gas from fan 23 flows efficiently between cathode electrode 20a and anode electrode 20b. Insulating guide 28 and electrical insulating plate 26 are formed of ceramic such as alumina (Al2O3), which has low reactivity with fluorine gas.

[0025] Conductive guide 29 is disposed on the surface of ground plate 21 facing discharge space 27, sandwiching anode electrode 20b therebetween. Similar to insulating guide 28, conductive guide 29 is formed in a shape that guides the flow of laser gas so that the laser gas from fan 23 flows efficiently between cathode electrode 20a and anode electrode 20b. Conductive guide 29 is formed, for example, from porous nickel metal that has low reactivity with fluorine gas.

[0026] Laser gas supply device 18a and laser gas exhaust device 18b are connected to laser 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.

[0027] Windows 19a and 19b are provided at the ends of the container 10a to emit light generated within the container 10a to the outside. The laser chamber 10 is arranged so that the optical path of the optical resonator passes through the discharge space 27 and the windows 19a and 19b.

[0028] The line narrowing module 15 includes a prism 15a and a grating 15b. The prism 15a expands the beam width of the light emitted from the laser chamber 10 through a window 19a and transmits the expanded beam toward the grating 15b.

[0029] Grating 15b is arranged in a Littrow configuration, where the angle of incidence and the angle of diffraction are the same. Grating 15b is a wavelength selection element that selectively extracts light near a specific wavelength depending on the diffraction angle. The spectral width of the light returning from grating 15b to laser chamber 10 via prism 15a is narrowed.

[0030] The output coupling mirror 16 transmits a portion of the light emitted from the laser chamber 10 via the window 19b and reflects the other portion back into the laser chamber 10. The surface of the output coupling mirror 16 is coated with a partially reflective film.

[0031] The light emitted from the laser chamber 10 travels back and forth between the line 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. The wavelength of the pulsed laser light PL is in the ultraviolet region of 150 nm to 380 nm, which is the oscillation wavelength of an excimer laser device, for example.

[0032] The pulse energy measuring unit 13 is disposed in the optical path of the pulsed laser light PL output via the output coupling mirror 16. The pulse energy measuring unit 13 includes a beam splitter 13a, a focusing optical system 13b, and an optical sensor 13c.

[0033] The beam splitter 13a transmits the pulsed laser light PL with high transmittance and reflects a portion of the pulsed laser light PL toward the focusing optical system 13b. The focusing optical system 13b focuses the light reflected by the beam splitter 13a on the light-receiving surface of the optical sensor 13c. The optical sensor 13c measures the pulse energy of the light focused on the light-receiving surface and outputs the measurement value to the processor 14.

[0034] The pressure sensor 17 detects the gas pressure inside the container 10a and outputs the detected value to the processor 14. The processor 14 determines the gas pressure of the laser gas inside the container 10a based on the detected gas pressure value and the charging voltage of the charger 11.

[0035] The charger 11 is a high-voltage power supply that supplies a charging voltage to a charging capacitor included in the PPM 12. The switch SW of the PPM 12 is controlled by the processor 14. When the switch SW changes from off to on, the PPM 12 generates a high-voltage pulse from the electrical energy stored in the charging capacitor and applies it to the main electrode 20.

[0036] The processor 14 is a processing device that transmits and receives various signals to and from an exposure apparatus controller 110 provided in the exposure apparatus 100. For example, the processor 14 receives from the exposure apparatus controller 110 a target pulse energy of the pulsed laser light PL output to the exposure apparatus 100, an oscillation trigger signal, and the like.

[0037] The processor 14 comprehensively controls the operation of each component of the gas laser device 2 based on various signals sent from the exposure apparatus controller 110, measured values ​​of pulse energy, detected values ​​of gas pressure, and the like.

[0038] The processor 14 functions as a controller for the gas laser device 2. For example, the processor 14 is a processing device including a storage device in which a control program is stored and a CPU (Central Processing Unit) that executes the control program. The processor 14 is specially configured or programmed to execute various processes included in the present disclosure. The storage device is a non-transitory computer-readable storage medium, and includes, for example, a memory that is a primary storage device and a storage that is an auxiliary storage device. The storage device may be a semiconductor memory, a hard disk drive (HDD) device, a solid-state drive (SSD) device, or a combination of two or more of these.

[0039] The gas laser device 2 is not necessarily limited to a line-narrowing laser device, but may be a laser device that outputs spontaneously oscillated light. For example, instead of the line-narrowing module 15, a high-reflection mirror may be provided.

[0040] 3 shows in detail the configuration near the main electrode 20 of the laser chamber 10. In the following explanation, the upstream side refers to the side from which the laser gas flows into the discharge space 27, relative to the discharge space 27. The downstream side refers to the side from which the laser gas flows out of the discharge space 27, relative to the discharge space 27.

[0041] The preionization outer electrode 31 is disposed between the anode electrode 20b and the dielectric pipe 32, and is held in contact with the side surface of a metal holding member 34. The holding member 34 is fixed to the upstream side surface of the anode electrode 20b. The preionization inner electrode 33 is disposed inside the dielectric pipe 32, and the preionization outer electrode 31 is in contact with the outside of the dielectric pipe 32.

[0042] The insulating guide 28 is disposed so as to cover the upstream and downstream side surfaces of the cathode electrode 20a. The surface of the insulating guide 28 is inclined so that the surface approaches the electrical insulating plate 26 as it becomes farther away from the cathode electrode 20a.

[0043] The conductive guide 29 includes a first guide member 29a, a second guide member 29b, and a third guide member 29c. The first guide member 29a and the third guide member 29c are disposed upstream of the anode electrode 20b. The second guide member 29b is disposed downstream of the anode electrode 20b.

[0044] First guide member 29a is disposed on ground plate 21 so as to guide laser gas into discharge space 27. Dielectric pipe 32 is disposed between first guide member 29a and anode electrode 20b, spaced apart from ground plate 21 and anode electrode 20b. Second guide member 29b is disposed on ground plate 21 downstream of anode electrode 20b so as to cover the downstream side surface of anode electrode 20b.

[0045] The third guide member 29c is disposed between the dielectric pipe 32 and the anode electrode 20b so as to cover the upstream side surface of the anode electrode 20b and to guide the laser gas to the discharge space 27. The third guide member 29c is located close to the dielectric pipe 32.

[0046] The surface of the conductive guide 29 is generally inclined so that the further away from the anode electrode 20b it is, the closer it is to the ground plate 21.

[0047] In this way, the insulating guide 28 and the conductive guide 29 form a flow path for the laser gas. In order to maximize the flow speed of the laser gas flowing through the discharge space 27 and to prevent the acoustic waves generated by the main discharge from being reflected and returning to the discharge space 27, the width of the flow path in the Y direction is made wider the further away from the discharge space 27. Also, in order to prevent the acoustic waves generated by the main discharge from being reflected by the inner wall 10b inside the container 10a and returning to the discharge space 27, the portion of the inner wall 10b that faces the discharge space 27 in the X direction is inclined with respect to the Y direction, which is the discharge direction. The acoustic waves are compressional waves of the laser gas.

[0048] The upstream and downstream side surfaces of the cathode electrode 20a near its discharge surface are not covered with the insulating guide 28, and protrude from the surface of the insulating guide 28 toward the anode electrode 20b. As a result, the discharge surface of the cathode electrode 20a is spaced apart from the surface of the insulating guide 28.

[0049] The upstream and downstream side surfaces of the anode electrode 20b near its discharge surface are not covered with the conductive guide 29, and protrude from the surface of the conductive guide 29 toward the cathode electrode 20a. As a result, the discharge surface of the anode electrode 20b is spaced apart from the surface of the conductive guide 29.

[0050] 1.2 Operation Next, the operation of gas laser apparatus 2 according to the comparative example will be described. First, processor 14 controls laser gas supply device 18a to supply laser gas into container 10a of laser chamber 10, and drives motor 23a to rotate fan 23. This causes the laser gas filled in container 10a to circulate as shown by the arrows in FIG.

[0051] The processor 14 receives the target pulse energy and the oscillation trigger signal transmitted from the exposure apparatus controller 110. The oscillation trigger signal is a signal that instructs the gas laser apparatus 2 to output one pulse of pulsed laser light PL.

[0052] The processor 14 sets a charging voltage according to the target pulse energy in the charger 11. The processor 14 operates the switch SW of the PPM 12 in synchronization with the oscillation trigger signal.

[0053] When the switch SW of the PPM 12 is turned from off to on, a voltage is applied between the preionization inner electrode 33 and the preionization outer electrode 31 of the preionization electrode 30, and between the cathode electrode 20a and the anode electrode 20b. This causes a corona discharge at the preionization electrode 30, generating UV (Ultraviolet) light. The laser gas in the discharge space 27 is irradiated with the UV light, thereby preionizing the laser gas.

[0054] Thereafter, when the voltage between the cathode electrode 20a and the anode electrode 20b reaches the breakdown voltage, a main discharge occurs in the discharge space 27. If the discharge direction of the main discharge is the direction in which electrons flow, then the discharge direction is from the cathode electrode 20a to the anode electrode 20b. When the main discharge occurs, the laser gas in the discharge space 27 is excited and emits light.

[0055] Light emitted from the laser gas is reflected by the line narrowing module 15 and the output coupling mirror 16 and travels back and forth within the laser resonator, resulting in laser oscillation. The light narrowed in line by the line narrowing module 15 is output from the output coupling mirror 16 as pulsed laser light PL.

[0056] A portion of the pulsed laser light PL output from the output coupling mirror 16 is incident on the pulse energy measuring unit 13. The pulse energy measuring unit 13 measures the pulse energy of the incident pulsed laser light PL and outputs the measurement value to the processor 14.

[0057] The processor 14 calculates the difference ΔE between the measured pulse energy and the target pulse energy, and based on the difference ΔE, the processor 14 feedback-controls the charging voltage so that the measured pulse energy becomes the target pulse energy.

[0058] When the charging voltage exceeds the maximum value of the allowable range, processor 14 controls laser gas supply device 18a to supply laser gas into container 10a until the predetermined pressure is reached. When the charging voltage falls below the minimum value of the allowable range, processor 14 controls laser gas exhaust device 18b to exhaust laser gas from container 10a until the predetermined pressure is reached.

[0059] The pulsed laser light PL that has passed through the pulse energy measuring unit 13 enters the exposure device 100 .

[0060] 1.3 Challenges FIG. 3 shows the flow of laser gas circulating within container 10a. After passing through discharge space 27 from the upstream side, the laser gas changes direction in the downstream space and then flows toward heat exchanger 24. This downstream space contains a region where stagnation occurs. In this region, a vortex is generated by part of the laser gas flow. This vortex compresses the laser gas flow path and becomes a source of resistance to the laser gas flow. As a result, the flow rate of the laser gas flowing through discharge space 27 decreases, and discharge products generated by the main discharge remain in discharge space 27, making the main discharge unstable, and the energy stability of the pulsed laser light PL deteriorates.

[0061] Therefore, an object of the present disclosure is to provide a laser chamber, a gas laser apparatus, and a method for manufacturing an electronic device that can improve the flow rate of the laser gas flowing through the discharge space 27.

[0062] 2. First embodiment 2.1 Configuration The gas laser device 2 according to the first embodiment of the present disclosure has the same configuration as the gas laser device 2 according to the comparative example, except that the configuration of the laser chamber 10 is different.

[0063] FIG. 4 shows in detail the configuration near the main electrode 20 of the laser chamber 10 according to the first embodiment. In this embodiment, a vortex dividing member 40 for dividing the above-mentioned vortices is provided inside the vessel 10a. In this embodiment, the vortex dividing member 40 is composed of a plurality of structures 50 that are discretely arranged along the flow of the laser gas, downstream of the insulating guide 28, which is arranged downstream of the cathode electrode 20a. The plurality of structures 50 are arranged with gaps between them. FIG. 4 shows the case where the vortex dividing member 40 includes two structures 50.

[0064] The structure 50 has an L-shaped cross section in the XY plane perpendicular to the Z direction. The structure 50 is a so-called bracket. The structure 50 extends in the Z direction while maintaining the same cross-sectional shape, and both ends in the Z direction are fixed to the inner wall 10b of the container 10a. In addition to both ends being fixed to the inner wall 10b, the structure 50 may also be supported by pillars (not shown) connected to the inner wall 10b.

[0065] The structure 50 is preferably made of, for example, aluminum with electroless nickel plating, alumina ceramic, nickel, or the like.

[0066] The structure 50 has two linear portions 51 that are perpendicular to each other in the XY plane. The two linear portions 51 have the same length and are connected to each other at their ends. The structure 50 is arranged so that each of the two linear portions 51 is inclined with respect to the Y direction, which is the discharge direction, in order to prevent reflected acoustic waves from returning to the discharge space 27.

[0067] In order to divide the vortex and suppress acoustic waves returning to the discharge space 27, the plurality of structures 50 are preferably sized and arranged so that the following conditions are met:

[0068] First, in the XY plane, the point where the inner wall 10b contacts the insulating guide 28 downstream of the cathode electrode 20a is defined as a first point P1, and the point where the inner wall 10b becomes parallel to the discharge direction is defined as a second point P2. In this disclosure, "contact" does not necessarily mean contact, but also includes proximity. In FIG. 4, the first point P1 is the point where the inner wall 10b is connected to the electrical insulating plate 26 in the XY plane. The second point P2 is the end of a slope of the inner wall 10b that is inclined with respect to the discharge direction. The distance in the Y direction between the first point P1 and the second point P2 is defined as a first distance L. h The distance in the X direction between the first point P1 and the second point P2 is defined as the second distance L w Let's say.

[0069] When the number of structures 50 included in the vortex dividing member 40 is N and the length of each of the two straight portions 51 is S, it is preferable that the following formulas (1) and (2) are satisfied. S≦L h / (2N) ···(1) S≦L w / (2N) (2)

[0070] The point where the two linear portions 51 are connected is defined as the vertex A of the structure 50. The distance in the Y direction between the vertex A of the structure 50 that is closest to the first point P1 among the multiple structures 50 and the inner wall 10b is defined as L. a1h In this case, it is preferable that the following formula (3) is satisfied. 0 <L a1h ≦L h / (2N) ···(3)

[0071] Furthermore, the distance in the X direction between the vertex A of the structure 50 that is closest to the second point P2 among the plurality of structures 50 and the inner wall 10b is defined as L a1w In this case, it is preferable that the following formula (4) is satisfied. 0 <L a1w ≦L w / (2N) ···(4)

[0072] The above formulas (3) and (4) include a range in which the orientation of the structure 50 in the XY plane is restricted in order to avoid contact with the inner wall 10b.

[0073] The distance in the Y direction between the vertices A of two adjacent structures 50 is L. a2h In this case, it is preferable that the following formula (5) is satisfied. L a2h ≦(L h -S / 2-L a1h ) / (N-1) (5)

[0074] Furthermore, the distance in the X direction between the vertices A of two adjacent structures 50 is L a2w In this case, it is preferable that the following formula (6) is satisfied. L a2w ≦(L w -S / 2-La1w ) / (N-1) (6)

[0075] It should be noted that two adjacent structures 50 refer to a combination of one structure 50 and another structure 50 having a vertex A that is closest to the vertex A of the first structure 50.

[0076] 2.2 Operation The operation of the gas laser device 2 according to this embodiment is the same as that of the comparative example, except for the difference in function due to the provision of the vortex dividing member 40 inside the vessel 10a.

[0077] Fig. 5 shows an example of the flow of laser gas in the first embodiment. As shown in Fig. 5, in this embodiment, as in the comparative example, stagnation occurs in the space downstream from discharge space 27, and a vortex occurs in the region where this stagnation occurs, but this vortex is divided into multiple small vortices by vortex dividing member 40.

[0078] 2.3 Effects In this embodiment, the vortex is divided into multiple smaller vortices by vortex dividing member 40, thereby reducing the flow path resistance of the laser gas caused by the vortex. As a result, the flow rate of the laser gas flowing through discharge space 27 increases and the amount of discharge products remaining in discharge space 27 decreases, improving the stability of the main discharge and the energy stability of the pulsed laser light PL. The applicant performed a simulation using "SOLIDWORKS 2019 Flow Simulation," a thermal fluid analysis software from Solidworks, and confirmed that the flow rate in this embodiment is 2% higher than in the comparative example.

[0079] Furthermore, vortex dividing member 40 is made up of multiple structures 50 arranged discretely along the flow of laser gas, and has a small area for reflecting acoustic waves, so that it is possible to suppress acoustic waves that are reflected by vortex dividing member 40 and return to discharge space 27. Furthermore, by arranging each of two linear portions 51 so that they are inclined with respect to the Y direction, which is the discharge direction, it is possible to further suppress acoustic waves that return to discharge space 27. By suppressing acoustic waves that return to discharge space 27 in this way, the energy stability of pulsed laser light PL is further improved.

[0080] 3. Second embodiment 3.1 Configuration A gas laser device 2 according to the second embodiment of the present disclosure has the same configuration as the gas laser device 2 according to the first embodiment, except that the configuration of the laser chamber 10 is different.

[0081] FIG. 6 shows in detail the configuration near the main electrode 20 of the laser chamber 10 according to the second embodiment. In this embodiment, as in the first embodiment, a vortex dividing member 40 for dividing the above-mentioned vortices is provided inside the vessel 10a. In this embodiment, the vortex dividing member 40 is composed of a plurality of structures 60 that are discretely arranged along the flow of the laser gas downstream of the insulating guide 28, which is arranged downstream of the cathode electrode 20a. FIG. 6 shows the case where the vortex dividing member 40 includes two structures 60.

[0082] The structure 60 has the same configuration as the structure 50 of the first embodiment, except for its cross-sectional shape. The structure 60 has a circular cross-sectional outer shape in the XY plane perpendicular to the Z direction. The structure 60 is a so-called cylindrical bar. In this embodiment, the structure 60 is a hollow cylinder having a circular hollow portion. Note that the structure 60 may also be a solid cylinder without a hollow portion.

[0083] The structure 60 extends in the Z direction while maintaining the same cross-sectional shape, and both ends in the Z direction are fixed to the inner wall 10b of the container 10a. In addition to both ends being fixed to the inner wall 10b, the structure 60 may be supported by supports (not shown) connected to the inner wall 10b.

[0084] The structure 60 is preferably made of, for example, aluminum with electroless nickel plating, alumina ceramic, nickel, or the like.

[0085] The size and arrangement of the plurality of structures 60 are preferably determined so as to satisfy the following conditions in order to divide the vortex and suppress the acoustic waves returning to the discharge space 27. Note that the first point P1, the second point P2, the first distance L h , and the second distance L w The definitions are the same as in the first embodiment.

[0086] When the number of structures 60 included in the vortex dividing member 40 is N and the outer diameter of the structure 60 is D, it is preferable that the following formulas (7) and (8) are satisfied. D≦L h / (2N) ···(7) D≦L w / (2N) ···(8)

[0087] The distance in the Y direction between the center C of the structure 60 closest to the first point P1 and the inner wall 10b is defined as L. c1h In this case, it is preferable that the following formula (9) is satisfied. 0 <L c1h ≦L h / (2N) ···(9)

[0088] Furthermore, the distance in the X direction between the center C of the structure 60 that is closest to the second point P2 and the inner wall 10b is defined as L c1w In this case, it is preferable that the following formula (10) is satisfied. 0 <L c1w ≦L w / (2N) ···(10)

[0089] The distance in the Y direction between the centers C of two adjacent structures 60 is L c2h In this case, it is preferable that the following formula (11) is satisfied. L c2h ≦(L h -D / 2-Lc1h ) / (N-1) (11)

[0090] Furthermore, the distance in the X direction between the centers C of two adjacent structures 60 is L c2w In this case, it is preferable that the following formula (12) is satisfied. L c2w ≦(L w -D / 2-L c1w ) / (N-1) (12)

[0091] It should be noted that two adjacent structures 60 refer to a combination of one structure 60 and another structure 60 having a center C that is closest to the center C of the first structure 60.

[0092] 3.2 Operation The operation of the gas laser device 2 according to this embodiment is the same as that of the comparative example, except for the difference in function due to the provision of the vortex dividing member 40 inside the vessel 10a.

[0093] Fig. 7 shows an example of the flow of laser gas in the second embodiment. As shown in Fig. 7, in this embodiment, as in the first embodiment, the vortex is divided into a plurality of small vortices by the vortex dividing member 40.

[0094] 3.3 Effects In this embodiment, as in the first embodiment, the vortex is divided into a plurality of small vortices by the vortex dividing member 40, thereby improving the energy stability of the pulsed laser light PL. Furthermore, by performing a simulation, it was confirmed that the flow velocity in this embodiment is 1% higher than in the comparative example.

[0095] Furthermore, in this embodiment, the vortex dividing member 40 is also made up of a plurality of structures 60 that are discretely arranged along the flow of the laser gas, and the area that reflects the acoustic waves is small, so that it is possible to suppress the acoustic waves that are reflected by the vortex dividing member 40 and return to the discharge space 27. Furthermore, in this embodiment, the cross-sectional shape of the structures 60 is circular, so it is possible to further suppress the acoustic waves that return to the discharge space 27. By suppressing the acoustic waves that return to the discharge space 27 in this way, the energy stability of the pulsed laser light PL is further improved.

[0096] 4. Third embodiment 4.1 Configuration The gas laser device 2 according to the third embodiment of the present disclosure has the same configuration as the gas laser device 2 according to the first embodiment, except that the configuration of the laser chamber 10 is different.

[0097] 8 shows in detail the configuration near the main electrode 20 of the laser chamber 10 according to the third embodiment. In this embodiment, as in the first embodiment, a vortex dividing member 40 for dividing the above-mentioned vortices is provided inside the vessel 10a. In this embodiment, the vortex dividing member 40 is a mesh plate 70 that is arranged along the flow of the laser gas downstream of the insulating guide 28 that is arranged downstream of the cathode electrode 20a.

[0098] The mesh plate 70 extends in the Z direction while maintaining the same cross-sectional shape, and both ends in the Z direction are fixed to the inner wall 10b of the container 10a. Also, both ends of the mesh plate 70 in the XY plane are in contact with the inner wall 10b. In addition to both ends being fixed to the inner wall 10b, the mesh plate 70 may be supported by supports (not shown) connected to the inner wall 10b.

[0099] The mesh plate 70 is a mesh-like member and has a plurality of two-dimensional openings 71. In other words, the mesh plate 70 is made up of a plurality of structures that are discretely arranged along the flow of the laser gas.

[0100] The mesh plate 70 is preferably made of, for example, aluminum electrolessly plated with nickel, alumina ceramic, nickel, or the like.

[0101] The mesh plate 70 is preferably arranged so as to satisfy the following conditions in order to divide the vortex and suppress the acoustic waves returning to the discharge space 27. Note that the first point P1, the second point P2, and the first distance L h , and the second distance L w The definitions are the same as in the first embodiment.

[0102] Of the two points where the mesh plate 70 and the inner wall 10b contact on the XY plane, the one closer to the first point P1 is designated as a third point P3, and the one closer to the second point P2 is designated as a fourth point P4. The distance in the Y direction between the third point P3 and the fourth point P4 is designated as L. mh In this case, it is preferable that the following formula (13) is satisfied. 0.25L h ≦L mh ≦L h ···(13)

[0103] Also, the distance in the X direction between the third point P3 and the fourth point P4 is L mw In this case, it is preferable that the following formula (14) is satisfied. 0.25L w ≦L mw ≦L w ···(14)

[0104] In this way, the mesh plate 70 is preferably disposed in a space defined by the line K connecting the first point P1 and the second point P2 and the inner wall 10b.

[0105] In this embodiment, the mesh plate 70 is arranged on a straight line connecting the third point P3 and the fourth point P4 on the XY plane, but may also be arranged on a curved line connecting the third point P3 and the fourth point P4.

[0106] In order to suppress acoustic waves returning to the discharge space 27, the mesh plate 70 preferably has, for example, two or more openings 71 per square inch. Furthermore, the mesh plate 70 preferably has an opening ratio of 50% or more and 80% or less.

[0107] 4.2 Operation The operation of the gas laser device 2 according to this embodiment is the same as that of the comparative example, except for the difference in function due to the provision of the vortex dividing member 40 inside the vessel 10a.

[0108] Fig. 9 shows an example of the flow of laser gas in the third embodiment. As shown in Fig. 9, in this embodiment, as in the first embodiment, the vortex is divided into a plurality of small vortices by the vortex dividing member 40.

[0109] 4.3 Effects In this embodiment, as in the first embodiment, the vortex is divided into a plurality of small vortices by the vortex dividing member 40, thereby improving the energy stability of the pulsed laser light PL. Furthermore, by performing a simulation, it was confirmed that the flow velocity in this embodiment is 1% higher than in the comparative example.

[0110] Furthermore, in this embodiment, the vortex dividing member 40 is a mesh plate 70 made up of a plurality of structures discretely arranged along the flow of the laser gas, and has a small area for reflecting acoustic waves, so that it is possible to suppress acoustic waves that are reflected by the vortex dividing member 40 and return to the discharge space 27. By suppressing the acoustic waves that return to the discharge space 27 in this way, the energy stability of the pulsed laser light PL is further improved.

[0111] 5. Fourth embodiment 5.1 Configuration The gas laser device 2 according to the fourth embodiment of the present disclosure has the same configuration as the gas laser device 2 according to the first embodiment, except that the configuration of the laser chamber 10 is different.

[0112] 10 shows in detail the configuration near the main electrode 20 of the laser chamber 10 according to the fourth embodiment. In this embodiment, as in the first embodiment, a vortex dividing member 40 for dividing the above-mentioned vortices is provided inside the vessel 10a. In this embodiment, the vortex dividing member 40 is configured by combining a plurality of structures 60 and a mesh plate 70.

[0113] The structure 60 has the same configuration as the structure 60 described in the second embodiment. The mesh plate 70 has the same configuration as the mesh plate 70 described in the third embodiment. The size and arrangement of the multiple structures 60 may be the same as in the second embodiment. The arrangement and opening ratio of the mesh plate 70 may be the same as in the second embodiment.

[0114] The mesh plate 70 is arranged in a curved shape so as to avoid the multiple structures 60. In this embodiment, the multiple structures 60 are arranged in a space surrounded by the mesh plate 70 and the inner wall 10b, and the multiple structures 60 are in contact with the mesh plate 70.

[0115] 5.2 Operation The operation of the gas laser device 2 according to this embodiment is the same as that of the comparative example, except for the difference in function due to the provision of the vortex dividing member 40 inside the vessel 10a.

[0116] An example of the flow of laser gas in the fourth embodiment is shown in Fig. 10. As shown in Fig. 10, in this embodiment, the vortex can be divided into a plurality of smaller vortices by the vortex dividing member 40 compared to the second and third embodiments.

[0117] 5.3 Effects According to this embodiment, the vortex can be divided into a plurality of smaller vortices than in the second and third embodiments, and therefore the flow path resistance can be further reduced and the flow rate of the laser gas flowing through the discharge space 27 can be further improved. This can further improve the energy stability of the pulsed laser light PL.

[0118] The vortex dividing member 40 may be configured by combining a plurality of structures 50 and a mesh plate 70. The structure 50 has the same configuration as the structure 50 described in the first embodiment.

[0119] 6. Manufacturing method of electronic devices 11 shows a schematic configuration example of an exposure apparatus 100. The exposure apparatus 100 includes an illumination optical system 104 and a projection optical system 106. The illumination optical system 104 illuminates a reticle pattern of a reticle (not shown) placed on a reticle stage RT with pulsed laser light PL incident thereon, for example, from a gas laser device 2. The projection optical system 106 reduces and projects the pulsed laser light PL that has passed through the reticle, forming an image on a workpiece (not shown) placed on a workpiece table WT. The workpiece is a photosensitive substrate such as a semiconductor wafer coated with photoresist.

[0120] Exposure apparatus 100 exposes a workpiece to pulsed laser light PL reflecting a reticle pattern by synchronously translating a reticle stage RT and a workpiece table WT. After transferring the reticle pattern to a semiconductor wafer through the exposure process described above, a semiconductor device can be manufactured through multiple processes. A semiconductor device is an example of an "electronic device" in this disclosure.

[0121] The gas laser device 2 is not limited to use in the manufacture of electronic devices, but can also be used for laser processing such as drilling.

[0122] The above description is intended to be illustrative rather than limiting. Thus, it will be apparent to those skilled in the art that modifications may be made to the embodiments of the present disclosure without departing from the scope of the appended claims.

[0123] Terms used throughout this specification and the appended claims should be interpreted as "open ended" terms. For example, the terms "include" or "including" should be interpreted as "not limited to what is stated as including." The term "having" should be interpreted as "not limited to what is stated as having." Additionally, the modifier "a" used in this specification and the appended claims should be interpreted as "at least one" or "one or more." Additionally, the term "at least one of A, B, and C" should be interpreted as "A," "B," "C," "A+B," "A+C," "B+C," or "A+B+C," and should also be interpreted as including combinations other than "A," "B," and "C."

Claims

1. A laser chamber of a gas laser device that outputs laser light, a container filled with laser gas; a first electrode extending in a first direction and disposed within the container; a second electrode extending in the first direction, facing the first electrode in a second direction perpendicular to the first direction, and disposed at a position closer to an inner wall of the container than the first electrode; a fan for causing the laser gas to flow through a discharge space between the first electrode and the second electrode; an insulating guide disposed downstream of the second electrode; a vortex dividing member extending in the first direction and consisting of a plurality of structures discretely arranged downstream of the insulating guide along the direction in which the laser gas flows, and dividing a vortex generated by a portion of the flow of the laser gas; A laser chamber comprising:

2. 10. The laser chamber of claim 1, The structure is a bracket having two linear portions whose cross sections in a plane perpendicular to the first direction are orthogonal to each other.

3. 3. The laser chamber of claim 2, In a plane perpendicular to the first direction, a point where the inner wall contacts the insulating guide downstream of the second electrode is defined as a first point, a point where the slope of the inner wall becomes parallel to the second direction is defined as a second point, and a direction perpendicular to the first direction and the second direction is defined as a third direction. The distance between the first point and the second point in the second direction is L ｈ and the distance between the first point and the second point in the third direction is L ｗ When the number of the structures constituting the vortex dividing member is N and the length of each of the two linear portions is S, S≦L ｈ / (2N) and S≦L ｗ / (2N) is satisfied.

4. 4. The laser chamber of claim 3, The distance in the second direction between the vertex of the structure closest to the first point among the plurality of structures and the inner wall is defined as L ａ１ｈ In this case, <h2 style=";text-align:left;direction:ltr">0<L<h2 style=";text-align:left;direction:ltr"> ａ１ｈ <h2 style=";text-align:left;direction:ltr"> ≦L<h2 style=";text-align:left;direction:ltr"> ｈ <h2 style=";text-align:left;direction:ltr"> / (2N) is satisfied.

5. 5. The laser chamber of claim 4, The distance in the third direction between the vertex of the structure closest to the first point among the plurality of structures and the inner wall is defined as L ａ１ｗ In this case, <h2 style=";text-align:left;direction:ltr">0<L<h2 style=";text-align:left;direction:ltr"> ａ１ｗ <h2 style=";text-align:left;direction:ltr"> ≦L<h2 style=";text-align:left;direction:ltr"> ｗ <h2 style=";text-align:left;direction:ltr"> / (2N) is satisfied.

6. 6. The laser chamber of claim 5, The distance in the second direction between the vertices of two adjacent structures is defined as L ａ２ｈ In this case, L ａ２ｈ ≦(L ｈ -S / 2-L ａ１ｈ ) / (N-1) is satisfied.

7. 7. The laser chamber of claim 6, The distance in the third direction between the vertices of two adjacent structures is defined as L ａ２ｗ In this case, L ａ２ｗ ≦(L ｗ -S / 2-L ａ１ｗ ) / (N-1) is satisfied.

8. 10. The laser chamber of claim 1, The structure is a cylinder having a circular cross-sectional outer shape in a plane perpendicular to the first direction.

9. 9. The laser chamber of claim 8, In a plane perpendicular to the first direction, a point where the inner wall contacts the insulating guide downstream of the second electrode is defined as a first point, a point where the slope of the inner wall becomes parallel to the second direction is defined as a second point, and a direction perpendicular to the first direction and the second direction is defined as a third direction. The distance between the first point and the second point in the second direction is L ｈ and the distance between the first point and the second point in the third direction is L ｗ When the number of the structures constituting the vortex dividing member is N and the outer diameter of the structure is D, D≦L ｈ / (2N) and D≦L ｗ / (2N) is satisfied.

10. 10. The laser chamber of claim 9, The distance in the second direction between the center of the structure closest to the first point among the plurality of structures and the inner wall is defined as L ｃ１ｈ In this case, <h2 style=";text-align:left;direction:ltr">0<L<h2 style=";text-align:left;direction:ltr"> ｃ１ｈ <h2 style=";text-align:left;direction:ltr"> ≦L<h2 style=";text-align:left;direction:ltr"> ｈ <h2 style=";text-align:left;direction:ltr"> / (2N) is satisfied.

11. 11. The laser chamber of claim 10, The distance in the third direction between the center of the structure closest to the first point among the plurality of structures and the inner wall is defined as L ｃ１ｗ In this case, <h2 style=";text-align:left;direction:ltr">0<L<h2 style=";text-align:left;direction:ltr"> ｃ１ｗ <h2 style=";text-align:left;direction:ltr"> ≦L<h2 style=";text-align:left;direction:ltr"> ｗ <h2 style=";text-align:left;direction:ltr"> / (2N) is satisfied.

12. 12. The laser chamber of claim 11, The distance in the second direction between the centers of two adjacent structures is L ｃ２ｈ In this case, L ｃ２ｈ ≦(L ｈ -S / 2-L ｃ１ｈ ) / (N-1) is satisfied.

13. 13. The laser chamber of claim 12, The distance in the third direction between the centers of two adjacent structures is L ｃ２ｗ In this case, L ｃ２ｗ ≦(L ｗ -S / 2-L ｃ１ｗ ) / (N-1) is satisfied.

14. 9. The laser chamber of claim 8, The structure is a hollow cylinder having a hollow portion.

15. 10. The laser chamber of claim 1, The vortex dividing member is a mesh plate.

16. 16. The laser chamber of claim 15, In a plane perpendicular to the first direction, a point where the inner wall contacts the insulating guide downstream of the second electrode is defined as a first point, and a point where the slope of the inner wall becomes parallel to the second direction is defined as a second point. The vortex dividing member is disposed in a space defined by the inner wall and a line connecting the first point and the second point.

17. 10. The laser chamber of claim 1, The vortex dividing member is configured by a combination of a mesh plate and a plurality of cylinders each having a circular cross section in a plane perpendicular to the first direction.

18. 10. The laser chamber of claim 1, The vortex dividing member is configured by a combination of a mesh plate and a plurality of brackets each having two linear portions whose cross sections in a plane perpendicular to the first direction are orthogonal to each other.

19. A gas laser device comprising an optical resonator and a laser chamber arranged so that an optical path of the optical resonator passes through the laser chamber, and which outputs laser light, The laser chamber comprises: a container filled with laser gas; a first electrode extending in a first direction and disposed within the container; a second electrode extending in the first direction, facing the first electrode in a second direction perpendicular to the first direction, and disposed at a position closer to an inner wall of the container than the first electrode; a fan for causing the laser gas to flow through a discharge space between the first electrode and the second electrode; an insulating guide disposed downstream of the second electrode; a vortex dividing member extending in the first direction and consisting of a plurality of structures discretely arranged downstream of the insulating guide along the direction in which the laser gas flows, and dividing a vortex generated by a portion of the flow of the laser gas; Including, Gas laser device.

20. A method for manufacturing an electronic device, comprising: A gas laser device comprising an optical resonator and a laser chamber arranged so that an optical path of the optical resonator passes through the laser chamber, and which outputs laser light, The laser chamber comprises: a container filled with laser gas; a first electrode extending in a first direction and disposed within the container; a second electrode extending in the first direction, facing the first electrode in a second direction perpendicular to the first direction, and disposed at a position closer to an inner wall of the container than the first electrode; a fan for causing the laser gas to flow through a discharge space between the first electrode and the second electrode; an insulating guide disposed downstream of the second electrode; a vortex dividing member extending in the first direction and consisting of a plurality of structures discretely arranged downstream of the insulating guide along the direction in which the laser gas flows, and dividing a vortex generated by a portion of the flow of the laser gas; Including, generating the laser light by a gas laser device; outputting the laser light to an exposure device; exposing a photosensitive substrate to the laser light in the exposure apparatus to manufacture an electronic device; A method for manufacturing electronic devices.

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