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

Abstract

To provide a laser chamber which enhances the cooling capacity of laser gas without increasing the pressure loss of the laser gas.SOLUTION: The laser chamber 10 includes a vessel 10a filled with a laser gas, a first electrode 20a extending in a first direction and disposed in the vessel, a second electrode 20b extending in the first direction and disposed at a position closer to an inside wall of the vessel than the first electrode while facing the first electrode in a second direction orthogonal to the first direction, a fan 23 configured to cause the laser gas to flow through a discharge space between the first and second electrodes, a plurality of heat pipes 40 disposed on the inside wall of the vessel, and a plurality of heat exchangers 50 disposed apart from each other in the vessel.SELECTED DRAWING: Figure 3

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 JP 2002-151763 A

[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 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 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, a plurality of heat pipes arranged on the inner wall of the container, and a plurality of heat exchangers arranged spaced apart from each other within the container.

[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 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, a plurality of heat pipes arranged on the inner wall of the container, and a plurality of heat exchangers arranged spaced apart from each other within the container.

[0007] A method for manufacturing an electronic device according to one aspect of the present disclosure includes a gas laser apparatus that outputs laser light and that 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, a plurality of heat pipes arranged on the inner wall of the container, and a plurality of heat exchangers arranged spaced apart from each other within the container, generating laser light using the gas laser apparatus, outputting the laser light to an exposure apparatus, and exposing a photosensitive substrate to the laser light in the exposure apparatus to manufacture an electronic device. [Brief explanation of the drawings]

[0008] Some embodiments of the present disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which: [Figure 1] FIG. 1 is a 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 laser chamber according to the embodiment. [Figure 4] FIG. 4 is a cross-sectional view showing a cross section of the bottom of the container taken along the YZ plane. [Figure 5] FIG. 5 is a cross-sectional view showing the configuration of the heat exchanger. [Figure 6] FIG. 6 is a diagram showing an example of a connection state of a plurality of heat exchangers. [Figure 7] FIG. 7 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. Embodiment 2.1 Configuration 2.2 Operation 2.3 Effects 3. Manufacturing methods for 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 is a line-narrowed gas laser device including 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 positioned closer to the inner wall 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] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] The pulsed laser light PL that has passed through the pulse energy measuring unit 13 enters the exposure device 100 .

[0050] Inside the vessel 10a, discharge products are generated by the main discharge in the discharge space 27. The generated discharge products are carried away from the discharge space 27 by the gas flow generated by the fan 23. This stabilizes the discharge. The main discharge also raises the temperature of the laser gas. As the heated laser gas passes through the heat exchanger 24, it is cooled by the cooling water flowing inside the heat exchanger 24.

[0051] 1.3 Challenges When the repetition rate of the pulsed laser light PL output from the gas laser device 2 according to the comparative example is increased, the temperature of the laser gas rises further, and therefore it is necessary to increase the cooling capacity of the laser gas by the heat exchanger 24. One possible way to increase the cooling capacity of the laser gas is to make the heat exchanger 24 larger, but increasing the size of the heat exchanger 24 increases the pressure loss of the laser gas due to the heat exchanger 24. When the pressure loss increases, the flow rate of the laser gas in the discharge space 27 decreases, making it difficult to operate the pulsed laser light PL at a high repetition rate.

[0052] Therefore, an object of the present disclosure is to increase the cooling capacity of the laser gas without increasing the pressure loss of the laser gas.

[0053] 2. Embodiment 2.1 Configuration The gas laser device 2 according to the 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.

[0054] 3 shows in detail the configuration of the laser chamber 10 according to the embodiment. The laser chamber 10 according to the embodiment differs from the comparative example only in that a plurality of heat pipes 40 and a plurality of heat exchangers 50 are provided inside the container 10a. The plurality of heat exchangers 50 are provided in place of the heat exchanger 24 of the comparative example.

[0055] Figure 4 shows a cross section of the bottom of the container 10a taken along line AA (i.e., the YZ plane) in Figure 3. A plurality of heat pipes 40 are arranged on the inner wall of the container 10a. Each of the plurality of heat pipes 40 is independent and individually arranged on the inner wall of the container 10a.

[0056] Specifically, the heat pipe 40 is fitted and fixed in a groove 10b formed in the inner wall of the container 10a. The heat pipe 40 is arranged parallel to the XY plane and extends across the bottom surface and two side surfaces of the inner wall of the container 10a. The length of the heat pipe 40 is preferably within a range of 70% to 90% of the circumferential length of the inner surface of the container 10a. The circumferential length of the inner surface of the container 10a refers to the length of the inner periphery when the container 10a is cut along the XY plane. The inner surface of the container 10a includes the bottom surface, two side surfaces, and the top surface of the inner wall. Furthermore, the heat pipe 40 is not limited to being arranged on the bottom surface and two side surfaces, and at least a portion of it may be arranged on the top surface.

[0057] The heat pipes 40 are arranged at regular intervals in the Z direction. The interval L between two adjacent heat pipes 40 is within a range of 100 mm to 300 mm.

[0058] The cross-sectional shape of the heat pipe 40 is, for example, circular. The outer diameter φ of the heat pipe 40 is preferably within the range of 5 mm to 10 mm. However, the cross-sectional shape of the heat pipe 40 may be a shape other than circular as long as it has a surface area similar to that of a circular pipe with an outer diameter within the range of 5 mm to 10 mm.

[0059] The heat pipe 40 is made of a material with high thermal conductivity, such as copper (Cu), and contains a highly volatile working fluid. The heat pipe 40 has a capillary structure formed on its inner surface.

[0060] 5 shows the configuration of a heat exchanger 50. The heat exchanger 50 is composed of a pipe 51 and a plurality of fins 52 formed on the outer periphery of the pipe 51. A liquid medium such as cooling water flows inside the pipe 51. The heat exchanger 50 extends in the Z direction. The plurality of heat exchangers 50 are parallel to one another.

[0061] As shown in FIG. 3, a plurality of heat exchangers 50 are arranged in the container 10a so as to avoid areas where the laser gas flow rate is high. Specifically, a plurality of heat exchangers 50 are arranged spaced apart in areas in the container 10a where the laser gas flow rate is 50% or less of the maximum flow rate. In this embodiment, the plurality of heat exchangers 50 are arranged in the first space S1, the second space S2, and the third space S3. The first space S1 is an area upstream of the discharge space 27 in the gas flow. The second space S2 is an area downstream of the discharge space 27 in the gas flow. The third space S3 is an area on the opposite side of the anode electrode 20b from the discharge space 27. The laser gas blown out from the fan 23 flows in this order through the first space S1, the second space S2, and the third space S3. The fan 23 is arranged in the third space S3.

[0062] The heat exchanger 50 may be provided in any region within the container 10a as long as the flow rate of the laser gas is 50% or less of the maximum flow rate. The number of heat exchangers 50 is not limited as long as it is two or more. In this embodiment, one heat exchanger 50 is provided in each of the first space S1, the second space S2, and the third space S3, but two or more heat exchangers 50 may be provided in each space.

[0063] 6 shows an example of a connection state of the plurality of heat exchangers 50. The ends of the plurality of heat exchangers 50 are commonly connected. Specifically, one end of each of the plurality of heat exchangers 50 is connected to a pipe 53a, and the other end is connected to a pipe 53b. The liquid medium flows into each of the plurality of heat exchangers 50 from the pipe 53a, and the liquid medium flowing out of each of the plurality of heat exchangers 50 flows into the pipe 53b. In this embodiment, the plurality of heat exchangers 50 are connected to the pipes 53a and 53b outside the container 10a, but may also be connected to the pipes 53a and 53b inside the container 10a.

[0064] For example, the total cooling capacity of the plurality of heat exchangers 50 is preferably within the range of 10 kW to 15 kW.

[0065] 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 action due to the provision of a plurality of heat pipes 40 and a plurality of heat exchangers 50 within the vessel 10a.

[0066] In this embodiment, in the high temperature region of the laser gas in the container 10a, latent heat is absorbed by the evaporation of the working fluid in the heat pipe 40. This absorption of latent heat cools the high temperature region. In contrast, in the low temperature region of the laser gas in the container 10a, latent heat is released by the condensation of the working fluid. This release of latent heat heats the low temperature region. The condensed working fluid returns to liquid and moves to the high temperature region by capillary action in the heat pipe 40. This phenomenon occurs repeatedly, thereby homogenizing the temperature of the laser gas in the container 10a. The heat of the laser gas whose temperature has been homogenized is discharged by the multiple heat exchangers 50.

[0067] 2.3 Effects When multiple heat pipes 40 are not provided inside the container 10a as in the comparative example, the temperature of the laser gas inside the container 10a becomes uneven, for example, being higher in the area downstream of the discharge space 27 than in other areas. For this reason, in order to improve the cooling efficiency of the laser gas, it is necessary to place the heat exchanger 50 in the area with high temperature, or to place a large heat exchanger 50.

[0068] In contrast to this, in this embodiment, multiple heat pipes 40 are arranged on the inner wall of container 10a, and the temperature of the laser gas is made uniform by the above-mentioned action. As a result, the same cooling efficiency can be obtained no matter where heat exchanger 50 is arranged inside container 10a, so heat exchanger 50 can be arranged to avoid areas with high laser gas flow rates so as not to increase pressure loss. Furthermore, by arranging multiple heat exchangers 50 to avoid areas with high laser gas flow rates, cooling capacity is improved.

[0069] Therefore, according to this embodiment, the cooling capacity of the laser gas can be increased without increasing the pressure loss of the laser gas when increasing the repetition rate of the pulsed laser light PL output from gas laser device 2. In particular, by arranging multiple heat exchangers 50 in an area within vessel 10a where the flow rate is 50% or less of the maximum flow rate of the laser gas, the cooling capacity of the laser gas can be increased while still suppressing pressure loss more efficiently than when heat exchangers 50 are arranged in an area with a higher flow rate.

[0070] Furthermore, if the temperature of the laser gas inside the container 10a is not uniform, thermal strain will occur in the container 10a. This will cause vibrations in the fan 23 and damage to brittle material parts. According to this embodiment, the temperature of the laser gas inside the container 10a is made uniform by the multiple heat pipes 40, so thermal strain in the container 10a can be suppressed.

[0071] 3. Manufacturing methods for electronic devices 7 shows a schematic configuration example of exposure apparatus 100. Exposure apparatus 100 includes an illumination optical system 104 and a projection optical system 106. 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. 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.

[0072] 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.

[0073] 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.

[0074] The above description is intended to be illustrative rather than limiting. Thus, it will be apparent to those skilled in the art that modifications can be made to the embodiments of the present disclosure without departing from the scope of the claims.

[0075] Terms used throughout this specification and claims should be construed as "open ended" unless expressly stated otherwise. For example, words such as "comprise," "have," "comprise," and "equip" should be construed as meaning "without excluding the presence of elements other than those listed." In addition, the modifier "a" should be construed as meaning "at least one" or "one or more." In addition, the term "at least one of A, B, and C" should be construed as "A," "B," "C," "A+B," "A+C," "B+C," or "A+B+C," and should also be construed as including combinations other than "A," "B," and "C."

Claims

1. A 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; a plurality of heat pipes disposed on an inner wall of the container; a plurality of heat exchangers disposed in the vessel at a distance from one another; A laser chamber comprising:

2. 10. The laser chamber of claim 1, Each of the plurality of heat pipes is arranged parallel to a plane perpendicular to the first direction.

3. 3. The laser chamber of claim 2, The plurality of heat pipes are arranged in the first direction at intervals within a range of 100 mm to 300 mm.

4. 3. The laser chamber of claim 2, The length of each of the plurality of heat pipes is within a range of 70% to 90% of the circumferential length of the inner surface of the container.

5. 10. The laser chamber of claim 1, The cross-sectional shape of each of the plurality of heat pipes is a circle with an outer diameter in the range of 5 mm to 10 mm.

6. 10. The laser chamber of claim 1, Each of the plurality of heat pipes has a capillary structure formed on its inner surface and is filled with a working fluid.

7. 10. The laser chamber of claim 1, Each of the plurality of heat pipes is fitted and fixed in a groove formed in the inner wall of the container.

8. 10. The laser chamber of claim 1, The plurality of heat exchangers are arranged in an area within the container where the flow rate of the laser gas is 50% or less of the maximum flow rate of the laser gas.

9. 10. The laser chamber of claim 1, The plurality of heat exchangers are arranged in a first space upstream of the discharge space, a second space downstream of the discharge space, and a third space on the opposite side of the discharge space with respect to the first electrode.

10. 10. The laser chamber of claim 1, The total cooling capacity of the plurality of heat exchangers is within the range of 10 kW to 15 kW.

11. 10. The laser chamber of claim 1, Each of the plurality of heat exchangers is composed of a pipe and a plurality of fins formed on the outer periphery of the pipe.

12. 12. The laser chamber of claim 11, The pipe extends in the first direction.

13. 10. The laser chamber of claim 1, The ends of the heat exchangers are commonly connected inside or outside the vessel.

14. 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 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; a plurality of heat pipes disposed on an inner wall of the container; a plurality of heat exchangers disposed in the vessel at a distance from one another; Including, Gas laser device.

15. 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 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; a plurality of heat pipes disposed on an inner wall of the container; a plurality of heat exchangers disposed in the vessel at a distance from one another; 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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