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

Abstract

A discharge excitation gas laser device is provided that has improved laser gas flow and improved energy efficiency. [Solution] The laser chamber of the discharge-excited gas laser device has a guide section arranged within the laser chamber so that a portion of the first guide surface extending from the front end of the guide surface at the upstream end in a first direction to the rear end of the guide surface at the downstream end in the direction opposite to the first direction extends over a first section corresponding to a phase angle of 90° or more of the first and second virtual logarithmic spirals, between a first virtual curve whose curvature decreases along the flow direction, from a first phase angle to a second phase angle of the first virtual logarithmic spiral, and the angle at which a straight line from the origin and a tangent to the first virtual curve intersect is 103°, and a second virtual curve whose curvature decreases along the flow direction, from a first phase angle to a second phase angle of the second virtual logarithmic spiral, and the angle at which a straight line from the origin and a tangent to the second virtual curve intersects is 96°.

Description

[Technical Field]

[0001] The present disclosure relates to a laser chamber, a discharge-pumped 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 can be ignored. 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. A gas laser device that narrows the spectral linewidth is called a line narrowing gas laser device. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Summary of JP 2022-112652 A

[0005] A laser chamber of a discharge-pumped gas laser apparatus according to one aspect of the present disclosure comprises first and second discharge electrodes arranged opposite each other in a direction parallel to a first direction, each of the first and second discharge electrodes extending in a second direction perpendicular to the first direction, a fan arranged in the laser chamber to circulate laser gas in the laser chamber, a cooling unit arranged in the laser chamber to cool the laser gas, and a guide unit that rotates the flow direction of laser gas that has passed between the first and second discharge electrodes in a third direction perpendicular to both the first and second directions around an axis parallel to the second direction to direct the laser gas towards the cooling unit, wherein when the laser chamber is viewed in cross section on a plane perpendicular to the second direction, an end of the guide unit that is upstream in the flow direction and faces the first direction and a guide unit disposed in the laser chamber so as to extend over a first section corresponding to a phase angle of 90° or greater of the first and second virtual logarithmic spirals between a first virtual curve whose curvature decreases along the flow direction, the first virtual curve extending from a first phase angle to a second phase angle of the first virtual logarithmic spiral, the first virtual curve having a curvature decreasing along the flow direction and having an angle of 103° between a straight line from the origin and a tangent to the first virtual curve, the second virtual curve having a curvature decreasing along the flow direction, the second virtual curve having a curvature decreasing along the flow direction and having an angle of 96° between a straight line from the origin and a tangent to the second virtual curve, the second virtual curve having a curvature decreasing along the flow direction, the second virtual curve having a curvature decreasing along the flow direction, having an angle of 96° between the first phase angle to the second phase angle of the second virtual logarithmic spiral.

[0006] A discharge excitation type gas laser apparatus according to one aspect of the present disclosure comprises an optical resonator, a laser chamber located in an optical path of the optical resonator, first and second discharge electrodes arranged opposite each other in a direction parallel to a first direction, each of the first and second discharge electrodes extending in a second direction perpendicular to the first direction, a fan arranged in the laser chamber to circulate laser gas in the laser chamber, a cooling unit arranged in the laser chamber to cool the laser gas, and a guide unit arranged in the laser chamber to rotate the flow direction of laser gas that has passed between the first and second discharge electrodes in a third direction perpendicular to both the first and second directions around an axis parallel to the second direction and direct the laser gas towards the cooling unit, wherein when the laser chamber is viewed in cross section on a plane perpendicular to the second direction, the guide unit is arranged on the upstream side in the flow direction and facing the first direction. and a guide unit disposed within the laser chamber so that at least a portion of the first guide surface extending from the front end of the guide surface, which is the end on the downstream side in the direction opposite to the first direction, extends over a first section corresponding to a phase angle of 90° or greater of the first and second virtual logarithmic spirals between: a first virtual curve whose curvature decreases along the flow direction, the first virtual curve extending from a first phase angle to a second phase angle of the first virtual logarithmic spiral, the first virtual curve having a curvature decreasing along the flow direction and having an angle of 103° between a straight line from the origin and a tangent to the first virtual curve, the second virtual curve having a curvature decreasing along the flow direction, the second virtual curve having a curvature decreasing along the flow direction and having an angle of 96° between a straight line from the origin and a tangent to the second virtual curve, the second virtual curve having a curvature decreasing along the flow direction,

[0007] A method for manufacturing an electronic device according to one aspect of the present disclosure includes an optical resonator, a laser chamber located in an optical path of the optical resonator, first and second discharge electrodes arranged opposite each other in a direction parallel to a first direction, each of the first and second discharge electrodes extending in a second direction perpendicular to the first direction, a fan arranged in the laser chamber to circulate laser gas in the laser chamber, a cooling unit arranged in the laser chamber to cool the laser gas, and a guide unit arranged in the laser chamber to rotate the flow direction of laser gas that has passed between the first and second discharge electrodes in a third direction perpendicular to both the first and second directions around an axis parallel to the second direction to direct the laser gas towards the cooling unit, wherein, when the laser chamber is viewed in cross section on a plane perpendicular to the second direction, the guide unit has a guide surface extending from a front end of the guide surface that is an upstream end in the flow direction of the guide unit and an end in the first direction, to a downstream end of the guide surface that is an end in the opposite direction to the first direction. the first virtual curve having a curvature decreasing along the flow direction, the first virtual curve extending from a first phase angle to a second phase angle of the first virtual logarithmic spiral, and the angle at which a straight line from the origin and a tangent to the first virtual curve intersects with the second virtual curve being 103°, the second virtual curve having a curvature decreasing along the flow direction, the second virtual curve having a curvature decreasing along the flow direction, the second virtual curve having a curvature decreasing along the flow direction, the second virtual curve having a curvature decreasing along the flow direction, the second virtual curve having a curvature decreasing along the flow direction, the second virtual curve having a curvature decreasing along the flow direction, the second virtual curve having a curvature decreasing along the flow direction, the second virtual curve having a curvature decreasing along the flow direction, the second virtual curve having a curvature decreasing along the flow direction, the second virtual curve having a curvature decreasing along the flow direction, the second virtual curve having a curvature decreasing along the flow direction, the second virtual curve having a curvature decreasing along the flow direction, the second virtual curve having a curvature decreasing along the flow direction, the [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 shows the configuration of a laser device in a comparative example. [Figure 2]FIG. 2 shows the configuration of a part of a laser device according to a comparative example as viewed in the −Z direction. [Figure 3] FIG. 3 shows the flow of laser gas in a comparative example. [Figure 4] FIG. 4 shows the configuration of the laser device according to the first embodiment. [Figure 5] FIG. 5 shows the configuration of a part of the laser device according to the first embodiment as seen in the −Z direction. [Figure 6] FIG. 6 shows the first and second hypothetical curves. [Figure 7] FIG. 7 shows a first example of the shape of the first guide surface extending between the first and second imaginary curves. [Figure 8] FIG. 8 shows a second example of the shape of the first guide surface extending between the first and second imaginary curves. [Figure 9] FIG. 9 shows a third example of the shape of the first guide surface extending between the first and second imaginary curves. [Figure 10] FIG. 10 shows a fourth example of the shape of the first guide surface extending between the first and second imaginary curves. [Figure 11] FIG. 11 shows a fifth example of how to construct the shape of the first guide surface extending between the first and second imaginary curves. [Figure 12] FIG. 12 shows a fifth example of the shape of the first guide surface obtained from FIG. [Figure 13] FIG. 13 shows a first example of a first section along which the first guide surface extends. [Figure 14] FIG. 14 shows a second example of the first section along which the first guide surface extends. [Figure 15] FIG. 15 shows a third example of the first section along which the first guide surface extends. [Figure 16] FIG. 16 shows a fourth example of the first section along which the first guide surface extends. [Figure 17] FIG. 17 shows the configuration of a part of the laser device according to the second embodiment as seen in the −Z direction. [Figure 18] FIG. 18 shows the configuration of the exposure system. Embodiment

[0009] <Contents> 1. Comparative Example 1.1 Configuration 1.2 Operation 2. Issues with the comparative example 3. Guide portion 28 with a small curvature along the direction of laser gas flow 3.1 Logarithmic spiral shaped first guide surface 281 3.2 First guide surface 281 including a combination of multiple arcs 3.3 First guide surface 281 including part of an ellipse 3.4 First guide surface 281 including a combination of multiple arcs and common circumtangents 3.5 Section along which the first guide surface 281 extends 3.6 Effect 4. Shape and position of guide portion 28 4.1 Inclination of the Second Guide Surface 282 4.2 Relationship with inclined member 12c 4.3 Effect 5.Other 5.1 Manufacturing methods for electronic devices 5.2 Laser Control Processor 30 5.3 Supplementary Information

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

[0011] 1. Comparative Example 1.1 Configuration 1 shows the configuration of a laser device 1 in a comparative example. The comparative example of the present disclosure is a configuration that the applicant recognizes as being known only by the applicant, and is not a publicly known example that the applicant acknowledges.

[0012] The laser apparatus 1 is a discharge-pumped gas laser apparatus capable of outputting laser light LB to an exposure apparatus 100. The laser apparatus 1 includes a laser chamber 10 including first and second discharge electrodes 11a and 11b, a power supply 13, a line-narrowing module 14, an output-coupling mirror 15, and a laser control processor 30. The line-narrowing module 14 and the output-coupling mirror 15 constitute an optical resonator. The laser chamber 10 includes windows 10a and 10b, which are arranged so that the windows 10a and 10b are located in the optical path of the optical resonator. The laser control processor 30 will be described later.

[0013] The traveling direction of the laser light LB output from the output coupling mirror 15 is defined as the Z direction. The first and second discharge electrodes 11a and 11b each extend in the Z direction. The direction in which the first and second discharge electrodes 11a and 11b face each other is defined as the V direction or -V direction. The Z direction and the V direction are perpendicular to each other, and the direction perpendicular to both of these directions is defined as the H direction or -H direction. The V direction, the Z direction, and the H direction correspond to the first, second, and third directions in this disclosure, respectively. Figure 1 shows the configuration of the laser device 1 as viewed in the -H direction.

[0014] 2 shows the configuration of a portion of a laser device 1 according to a comparative example as viewed in the -Z direction. A laser chamber 10 accommodates first and second discharge electrodes 11a and 11b, inclined members 12a to 12d, a cross-flow fan 21, a cooling unit 25, and a guide unit 28.

[0015] A laser gas containing, for example, argon gas or krypton gas as a rare gas, fluorine gas as a halogen gas, and neon gas as a buffer gas is sealed in the laser chamber 10. Alternatively, a laser gas containing fluorine gas and a buffer gas may be sealed.

[0016] An opening is formed in a part of the laser chamber 10, and this opening is blocked by an electrical insulator 20. The electrical insulator 20 supports the second discharge electrode 11b. A plurality of conductive parts 20a are embedded in the electrical insulator 20. Each of the conductive parts 20a is electrically connected to the second discharge electrode 11b. The power supply device 13 includes a charger (not shown) and is connected to the second discharge electrode 11b via the conductive parts 20a. The tilting members 12b and 12d each have a triangular prism shape and are fixed to the electrical insulator 20 so as to cover a portion of two side surfaces of the second discharge electrode 11b.

[0017] A return plate 10c is disposed inside the laser chamber 10. The first discharge electrode 11a is supported by the return plate 10c. The first discharge electrode 11a is electrically connected to ground potential via the return plate 10c and conductive members of the laser chamber 10. As shown in FIG. 2, the return plate 10c has gaps on the depth and front sides of the paper surface of FIG. 1 for allowing the laser gas to pass through. The tilting members 12a and 12c each have a triangular prism shape and are fixed to the return plate 10c so as to cover part of two side surfaces of the first discharge electrode 11a. The tilting members 12a and 12c may include a porous member for reducing acoustic waves generated from the discharge space between the first and second discharge electrodes 11a and 11b.

[0018] Inclined members 12a and 12b are arranged to gradually narrow the flow path of the laser gas so that the laser gas sent from cross flow fan 21 is efficiently guided to the discharge space between first and second discharge electrodes 11a and 11b. Inclined members 12c and 12d are arranged to gradually widen the flow path of the laser gas so that the laser gas that has passed through the discharge space is efficiently guided in a direction approaching guide portion 28.

[0019] The crossflow fan 21 includes a plurality of blades 21b arranged around a rotating shaft 21a. The rotating shaft 21a is connected to a motor (not shown). The crossflow fan 21 corresponds to the fan in this disclosure.

[0020] Cooling unit 25 includes a plurality of refrigerant pipes and heat dissipation fins arranged around each of the refrigerant pipes. Each of the refrigerant pipes is arranged so that its longitudinal direction extends in the Z direction. The refrigerant pipes are connected to heat exchanger 26 via pipes 26a and 26b.

[0021] The guide portion 28 is fixed to the inclined member 12c so as to guide the laser gas that has passed between the inclined members 12c and 12d to the cooling portion 25.

[0022] The line narrowing module 14 includes a prism 14a and a grating 14b. The prism 14a is disposed in the optical path of the light emitted from the window 10a. The grating 14b is disposed in the optical path of the light transmitted through the prism 14a. The output coupling mirror 15 is composed of a partial reflection mirror.

[0023] 1.2 Operation Laser control processor 30 receives a target value of pulse energy E and a light emission trigger signal from exposure apparatus 100. Based on the target value of pulse energy E, laser control processor 30 transmits setting data for a charging voltage to a charger included in power supply device 13. Laser control processor 30 also transmits a trigger signal to power supply device 13 based on the light emission trigger signal.

[0024] When the power supply device 13 receives a trigger signal from the laser control processor 30, it generates a pulsed high voltage from the electrical energy stored in the charger and applies this high voltage between the first and second discharge electrodes 11a and 11b.

[0025] When a high voltage is applied between the first and second discharge electrodes 11a and 11b, a discharge occurs between the first and second discharge electrodes 11a and 11b. The energy of this discharge excites the laser medium in the laser chamber 10, causing it to transition to a higher energy level. When the excited laser medium subsequently transitions to a lower energy level, it emits light with a wavelength corresponding to the difference in energy levels.

[0026] Light generated within the laser chamber 10 is emitted to the outside of the laser chamber 10 through windows 10a and 10b. The beam width of the light emitted from the window 10a of the laser chamber 10 in the H direction is expanded by the prism 14a, and the light is incident on the grating 14b.

[0027] Light incident on grating 14b is reflected by the multiple grooves of grating 14b and diffracted in a direction according to the wavelength of the light. The wavelength of the diffracted light incident on prism 14a from grating 14b is selected by matching the angle of incidence of the light incident on grating 14b with the diffraction angle of the diffracted light of the desired wavelength. Prism 14a reduces the beam width in the H direction of the diffracted light incident on grating 14b and returns the light to laser chamber 10 through window 10a.

[0028] The output coupling mirror 15 transmits and outputs a portion of the light emitted from the window 10 b of the laser chamber 10 , and reflects the other portion back into the laser chamber 10 .

[0029] In this way, the light emitted from the laser chamber 10 travels back and forth between the line-narrowing module 14 and the output coupling mirror 15, and is amplified each time it passes through the discharge space between the first and second discharge electrodes 11a and 11b. This light is narrowed in line each time it is reflected by the line-narrowing module 14. The laser-oscillated, line-narrowed light is output from the output coupling mirror 15 as laser light LB.

[0030] Fig. 3 shows the flow of laser gas in a comparative example. The components shown in Fig. 3 are the same as those in Fig. 2, but the pipes 26a and 26b and the heat exchanger 26 are omitted.

[0031] When a motor (not shown) rotates the crossflow fan 21, the laser gas flows as shown by the arrows in Fig. 3 and circulates inside the laser chamber 10. Discharge products generated by the discharge between the first and second discharge electrodes 11a and 11b are removed from the discharge space by the flow of laser gas before the next discharge occurs, leaving the discharge space and its vicinity with fewer discharge products, allowing the discharge to be stabilized.

[0032] Cooling unit 25 cools the laser gas by absorbing the thermal energy of the laser gas that has become hot due to the discharge. The thermal energy is discharged to the outside of laser chamber 10 via a coolant.

[0033] 2. Issues with the comparative example In Figure 3, the relative magnitude of the laser gas flow velocity is represented by the thickness of the arrows. The laser gas that passes between the first and second discharge electrodes 11a and 11b and between the inclined members 12c and 12d in the H direction passes between the inner surface of the laser chamber 10 and the guide portion 28, causing the flow direction of the laser gas to rotate around an axis parallel to the Z direction, and is then guided to the cooling portion 25. When this laser gas flow was simulated, it was found that in addition to the main flow that flows as a laminar flow along the inner surface of the laser chamber 10, stagnation occurs around the guide portion 28. It is presumed that this stagnation occurs because the inclination of the surface of the guide portion 28 changes abruptly with respect to the inclination of the surface of the inclined member 12c, causing the laser gas that flows along the surface of the inclined member 12c to separate from the surface of the guide portion 28 and become turbulent.

[0034] Such stagnation can impart flow resistance to the main flow of laser gas, causing the path of the main flow to be biased toward the inner surface of the laser chamber 10. This can reduce the flow path cross section of the main flow of laser gas, which is a laminar flow.

[0035] The main flow of laser gas flows into the cooling section 25 along the inner surface of the laser chamber 10. In the cooling section 25, the laser gas flows between multiple refrigerant pipes, causing split flows. However, because gas tends to flow according to its inertia, the flow rate of the split flows at positions far from the inner surface of the laser chamber 10 may be lower than that at positions closer to the inner surface of the laser chamber 10. In this case, the refrigerant pipes far from the inner surface of the laser chamber 10 may not be able to contribute sufficiently to cooling the laser gas, and conversely, the refrigerant pipes close to the inner surface of the laser chamber 10 may not be able to sufficiently cool the laser gas. For this reason, to achieve a sufficient cooling effect, it is necessary to increase the rotation speed of the crossflow fan 21 to increase the flow rate of the laser gas passing through the cooling section 25, which increases energy consumption. Furthermore, increasing the rotation speed of the crossflow fan 21 may make it more likely that the laser gas will separate from the surface of the guide section 28, causing turbulence.

[0036] The embodiments described below relate to providing a discharge excitation gas laser device that suppresses separation of laser gas from the surface of the guide portion 28, improves the flow of laser gas, and improves energy efficiency.

[0037] 3. Guide portion 28 with a small curvature along the direction of laser gas flow 3.1 Logarithmic spiral shaped first guide surface 281 4 shows the configuration of a laser device 1a according to the first embodiment. The laser device 1a differs from the comparative example in the shape of the guide portion 28.

[0038] FIG. 5 shows a partial configuration of the laser apparatus 1a according to the first embodiment as viewed in the -Z direction. The pipes 26a and 26b and the heat exchanger 26 are not shown. The guide portion 28 includes a guide surface front end 28a, which is the upstream end in the V direction in the laser gas flow direction, and a guide surface rear end 28b, which is the downstream end in the -V direction. The guide portion 28 includes a first guide surface 281 extending from the guide surface front end 28a to the guide surface rear end 28b, and a second guide surface 282 extending from the guide surface rear end 28b to the downstream side in the flow direction. When viewed in cross section on a plane perpendicular to the Z direction, the first guide surface 281 extends between the following first and second virtual curves L1 and L2.

[0039] FIG. 6 shows first and second imaginary curves L1 and L2. Each of the first and second imaginary curves L1 and L2 has a curvature that decreases along the flow direction. The first imaginary curve L1 is a portion of a first imaginary logarithmic spiral from a first phase angle θ1 to a second phase angle θ2, where the angle φ1 between a line from the origin O and a tangent to the first imaginary curve L1 is 103°. The second imaginary curve L2 is a portion of a second imaginary logarithmic spiral from a first phase angle θ1 to a second phase angle θ2, where the angle φ2 between a line from the origin O and a tangent to the second imaginary curve L2 is 96°. The first and second imaginary curves L1 and L2 have different angles φ1 and φ2, but share the same origin O and the same first and second phase angles θ1 and θ2. The angle difference θ2-θ1 between the first and second phase angles θ1 and θ2 is preferably 90° or more and 180° or less.

[0040] FIG. 7 shows a first example of the shape of the first guide surface 281 extending between the first and second virtual curves L1 and L2. The first guide surface 281 may have a logarithmic spiral shape, and the angle between a line from the origin of the logarithmic spiral and a tangent to the logarithmic spiral may be, for example, 99°. However, the origin of the logarithmic spiral constituting the first guide surface 281 does not have to be the same as the origin O of the first and second virtual logarithmic spirals. Furthermore, the first guide surface 281 does not have to have a perfect logarithmic spiral shape. By shaping the first guide surface 281 to extend between the first and second virtual curves L1 and L2, it is possible to create a shape whose curvature decreases along the flow direction.

[0041] 5, this shape causes the flow of laser gas to be attracted to first guide surface 281 by the Coanda effect. By reducing the curvature of first guide surface 281 along the flow direction, the Coanda effect is maintained over the entire length of first guide surface 281, and separation of laser gas from first guide surface 281 and the resulting occurrence of stagnation are suppressed. Therefore, uneven distribution of the main flow of laser gas is suppressed, and the difference in flow rate of the branch flows in cooling section 25 is reduced, which can improve cooling efficiency.

[0042] 3.2 First guide surface 281 including a combination of multiple arcs 8 shows a second example of the shape of the first guide surface 281 extending between the first and second virtual curves L1 and L2. The first guide surface 281 may include a combination of multiple arcs with different centers. The centers of the arcs are indicated by black circles. The arcs may have the same radius. There may be three or more arcs.

[0043] 9 shows a third example of the shape of the first guide surface 281 extending between the first and second virtual curves L1 and L2. The first guide surface 281 may include a combination of multiple arcs with different centers and increasing radii along the flow direction.

[0044] 3.3 First guide surface 281 including part of an ellipse 10 shows a fourth example of the shape of the first guide surface 281 extending between the first and second virtual curves L1 and L2. The first guide surface 281 may include a portion of an ellipse whose curvature changes along the flow direction. In addition to the ellipse, it may also include a circular arc. There may be multiple ellipses or circular arcs. Furthermore, instead of an ellipse, a quadratic curve other than an ellipse may be used.

[0045] 3.4 First guide surface 281 including a combination of multiple arcs and common circumtangents Fig. 11 shows a drawing method for a fifth example of the shape of the first guide surface 281 extending between the first and second virtual curves L1 and L2, and Fig. 12 shows the fifth example of the shape of the first guide surface 281 obtained from Fig. 11. The first guide surface 281 may include a combination of multiple arcs with different centers and their common circumstangents. There may be three or more arcs, and in that case the common circumstangents need only be the common circumstangents of arcs whose centers are adjacent to each other.

[0046] 3.5 Section along which the first guide surface 281 extends 7 to 12, the first guide surface 281 has been described as extending over the entire first and second virtual curves L1 and L2 from the first phase angle θ1 to the second phase angle θ2. The section from the first phase angle θ1 to the second phase angle θ2 corresponds to the second section in the present disclosure. In FIGS. 7 to 12, the guide surface front end 28a is located at a position corresponding to the first phase angle θ1, and the guide surface rear end 28b is located at a position corresponding to the second phase angle θ2. However, the present disclosure is not limited thereto. It is sufficient that the first guide surface 281 extends over the first section corresponding to a phase angle of 90° or greater of the virtual logarithmic spiral of the first and second virtual curves L1 and L2. The first section is a section within the second section.

[0047] 13 shows a first example of a first section over which the first guide surface 281 extends. The first guide surface 281 may extend over the first section from a first phase angle θ1 to a third phase angle θ3 between the first and second phase angles θ1 and θ2. The guide surface front end 28a may be located at a position corresponding to the first phase angle θ1.

[0048] 14 shows a second example of the first section over which the first guide surface 281 extends. The first guide surface 281 may extend over the first section from a third phase angle θ3 between the first and second phase angles θ1 and θ2 to the second phase angle θ2. The guide surface rear end 28b may be located at a position corresponding to the second phase angle θ2.

[0049] 15 shows a third example of the first section extending through the first guide surface 281. The first guide surface 281 may extend through the first section from a third phase angle θ3 between the first and second phase angles θ1 and θ2 to a fourth phase angle θ4 between the third and second phase angles θ3 and θ2.

[0050] 7 to 15, the first section is a continuous section, but the present disclosure is not limited to this. The first section may include multiple discontinuous sections within the second section, as long as the sum of the magnitudes of the phase angles thereof is 90° or greater.

[0051] 16 shows a fourth example of the first section over which the first guide surface 281 extends. The first guide surface 281 may extend over a first section including a section from the first phase angle θ1 to a third phase angle θ3 between the first and second phase angles θ1 and θ2, and a section from a fourth phase angle θ4 between the third and second phase angles θ3 and θ2 to the second phase angle θ2. The guide surface front end 28a may be located at a position corresponding to the first phase angle θ1, and the guide surface rear end 28b may be located at a position corresponding to the second phase angle θ2. The first section may include three or more discontinuous sections.

[0052] 3.6 Effect (1) According to the first embodiment, the laser chamber 10 of the discharge-pumped gas laser apparatus includes first and second discharge electrodes 11a and 11b, a cross-flow fan 21, a cooling unit 25, and a guide unit 28. The first and second discharge electrodes 11a and 11b are arranged facing each other in a direction parallel to the V direction, and each of the first and second discharge electrodes 11a and 11b extends in the Z direction perpendicular to the V direction. The cross-flow fan 21 is disposed in the laser chamber 10 and circulates the laser gas within the laser chamber 10. The cooling unit 25 is disposed in the laser chamber 10 and cools the laser gas. The guide unit 28 rotates the flow direction of the laser gas that has passed between the first and second discharge electrodes 11a and 11b in the H direction perpendicular to both the V and Z directions around an axis parallel to the Z direction, and directs the flow toward the cooling unit 25. The guide unit 28 is disposed in the laser chamber 10 such that, when the laser chamber 10 is viewed in cross section along a plane perpendicular to the Z direction, at least a portion of a first guide surface 281 extending from a guide surface front end 28a, which is an end of the guide unit 28 on the upstream side in the flow direction and in the V direction, to a guide surface rear end 28b, which is an end on the downstream side in the direction opposite to the V direction, extends between the first and second virtual curves L1 and L2 over a first section corresponding to a phase angle of 90° or greater of the first and second virtual logarithmic spirals. The first virtual curve L1 has a curvature that decreases along the flow direction, and is a virtual curve extending from a first phase angle θ1 to a second phase angle θ2 of the first virtual logarithmic spiral, in which the angle φ1 at which a straight line from the origin O intersects with a tangent to the first virtual curve L1 is 103°. The second virtual curve L2 is a virtual curve L2 whose curvature decreases along the flow direction, and is a virtual curve from the first phase angle θ1 to the second phase angle θ2 of the second virtual logarithmic spiral, in which the angle φ2 at which the line from the origin O intersects with the tangent to the second virtual curve L2 is 96°.

[0053] According to this, by extending first guide surface 281 between first and second virtual curves L1 and L2 whose curvature decreases along the flow direction, it is possible to prevent the flow of laser gas from separating from first guide surface 281. It is also possible to prevent stagnation of laser gas from occurring near first guide surface 281. This makes it possible to prevent uneven distribution of the flow of laser gas flowing into cooling section 25, thereby improving the cooling effect in cooling section 25 and improving energy efficiency.

[0054] (2) According to the second and third examples of the shape of the first guide surface 281 in the first embodiment, when viewed in cross section on a plane perpendicular to the Z direction, the first guide surface 281 includes a combination of multiple arcs having centers different from each other.

[0055] According to this, by configuring first guide surface 281 by combining a plurality of arcs, it is possible to obtain the effect of improving the flow of laser gas with a shape that is easy to manufacture.

[0056] (3) According to a third example of the shape of the first guide surface 281 in the first embodiment, when viewed in cross section on a plane perpendicular to the Z direction, the first guide surface 281 includes a combination of multiple arcs having different centers and increasing radii along the flow direction.

[0057] By increasing the radius of the arc along the flow direction, part of the first guide surface 281 can be made to resemble a logarithmic spiral whose curvature decreases along the flow direction. Also, the number of combined arcs can be reduced, making manufacturing easier.

[0058] (4) According to a fourth example of the shape of the first guide surface 281 in the first embodiment, when viewed in cross section on a plane perpendicular to the Z direction, the first guide surface 281 includes a portion of an ellipse whose curvature changes along the flow direction.

[0059] According to this, the ellipse has a large curvature near the end of the major axis and a smaller curvature toward the end of the minor axis, so by using part of the ellipse, part of the first guide surface 281 can be made to have a shape similar to a logarithmic spiral, with curvature decreasing along the flow direction.

[0060] (5) According to a fifth example of the shape of the first guide surface 281 in the first embodiment, when viewed in cross section on a plane perpendicular to the Z direction, the first guide surface 281 includes a combination of multiple arcs having different centers and their common circumtangents.

[0061] According to this, by combining a plurality of arcs and a common circumtangent, the recesses near the intersections of the plurality of arcs can be made linear, which can further improve the flow of laser gas.

[0062] (6) According to a fifth example of the shape of the first guide surface 281 in the first embodiment, when viewed in cross section on a plane perpendicular to the Z direction, the first guide surface 281 includes a combination of three or more arcs having different centers and a common circumtangent of arcs having centers adjacent to each other.

[0063] According to this, by combining three or more circular arcs, an improvement effect can be achieved over a wide range in the flow direction.

[0064] (7) In some examples of the first embodiment, the first guide surface 281 extends over a second section that includes the first section and corresponds to the first phase angle θ1 to the second phase angle θ2 of the first and second virtual logarithmic spirals.

[0065] This makes it possible to prevent the flow of laser gas from separating from first guide surface 281 over a wide range in the flow direction, and also to prevent stagnation of laser gas near first guide surface 281.

[0066] (8) According to some examples of the first embodiment, the guide surface front end 28a is located at a position corresponding to the first phase angle θ1, and the guide surface rear end 28b is located at a position corresponding to the second phase angle θ2.

[0067] This makes it possible to prevent the flow of laser gas from separating from first guide surface 281 over the entire first guide surface 281, and also to prevent stagnation of laser gas from occurring.

[0068] (9) According to a first example of the first section in the first embodiment, the first section is a section from the first phase angle θ1 to the third phase angle θ3 between the first and second phase angles θ1 and θ2, and the guide surface front end 28a is located at a position corresponding to the first phase angle θ1.

[0069] This improves the flow of laser gas in the first section from the first phase angle θ1 to the third phase angle θ3 where the guide surface front end 28a is located, and therefore the cooling effect in the cooling section 25 can be improved.

[0070] (10) According to the second example of the first section in the first embodiment, the first section is a section from the third phase angle θ3 between the first and second phase angles θ1 and θ2 to the second phase angle θ2, and the rear end 28b of the guide surface is located at a position corresponding to the second phase angle θ2.

[0071] This improves the flow of laser gas in the first section from the third phase angle θ3 to the second phase angle θ2 where the rear end 28b of the guide surface is located, thereby improving the cooling effect in the cooling section 25.

[0072] (11) According to the first to third examples of the first section in the first embodiment, the first section is a continuous section.

[0073] This improves the flow of laser gas in a continuous section of 90° or more, and therefore the cooling effect in cooling section 25 can be improved.

[0074] (12) According to a fourth example of the first section in the first embodiment, the first section includes a plurality of discontinuous sections in which the sum of the magnitudes of the phase angles is 90° or more.

[0075] According to this, even if there are a plurality of discontinuous sections, by making the total angle equal to or greater than 90°, the flow of the laser gas can be improved, and the cooling effect in cooling section 25 can be improved.

[0076] (13) According to the fourth example of the first section in the first embodiment, the front end 28a of the guide surface is located at a position corresponding to the first phase angle θ1, and the rear end 28b of the guide surface is located at a position corresponding to the second phase angle θ2.

[0077] This improves the flow of laser gas both near the front end 28a of the guide surface and near the rear end 28b of the guide surface, thereby improving the cooling effect in the cooling section 25.

[0078] In other respects, the first embodiment is similar to the comparative example.

[0079] 4. Shape and position of guide portion 28 4.1 Inclination of the Second Guide Surface 282 17 shows a partial configuration of the laser device 1a according to the second embodiment as seen in the -Z direction. The pipes 26a and 26b and the heat exchanger 26 are not shown. The arrangement direction of the first to third cooling pipes 251 to 253 arranged along the second guide surface 282 of the cooling unit 25 is defined as a fourth direction D4. In the first embodiment, the second guide surface 282 and the fourth direction D4 are substantially parallel to each other, but the present disclosure is not limited to this. It is sufficient that the angle α1 between the second guide surface 282 and the fourth direction D4 is 5° or less.

[0080] When the second guide surface 282 and the fourth direction D4 are not parallel, it is desirable that the first to third cooling pipes 251 to 253 are arranged so that the greater the distance from the rear end 28b of the guide surface, the closer they are to the second guide surface 282.

[0081] 4.2 Relationship with inclined member 12c 17, it is desirable that guide surface front end 28a coincide with the ridgeline that is the end of inclined member 12c in the H direction. Furthermore, when viewed in cross section on a plane perpendicular to the Z direction, it is desirable that a tangent to first guide surface 281 near guide surface front end 28a coincides with the surface of inclined member 12c. It is desirable that angle α2 between the tangent to first guide surface 281 near guide surface front end 28a and the H direction be 4° or less.

[0082] The inclined member 12c and the guide portion 28 are arranged so that a straight line inclined at an angle α3 with respect to the H direction passes through the inclined member 12c from the center of the discharge surface 11c of the first discharge electrode 11a facing the second discharge electrode 11b. The angle α3 is 6°.

[0083] 4.3 Effect (14) According to the second embodiment, the guide portion 28 includes a second guide surface 282 extending downstream in the flow direction from the guide surface rear end 28b. The cooling portion 25 includes first and second cooling pipes 251 and 252 aligned in a fourth direction D4 perpendicular to the Z direction and facing the second guide surface 282, and the angle α1 between the fourth direction D4 and the second guide surface 282 is 5° or less.

[0084] According to this, by making the fourth direction D4 in which the first and second cooling pipes 251 and 252 are aligned approximately parallel to the second guide surface 282, the laser gas can easily flow in the direction along the second guide surface 282, thereby improving the cooling efficiency of the entire cooling section 25.

[0085] (15) According to the second embodiment, the distance between the rear end 28b of the guide surface and the first cooling pipe 251 is shorter than the distance between the rear end 28b of the guide surface and the second cooling pipe 252, and the distance between the second guide surface 282 and the first cooling pipe 251 is longer than the distance between the second guide surface 282 and the second cooling pipe 252.

[0086] According to this, when the fourth direction D4 and the second guide surface 282 are inclined within a range of 5° or less, the distance from the second guide surface 282 becomes smaller as the distance from the rear end 28b of the guide surface increases, thereby making it possible to efficiently flow gas around the first and second cooling pipes 251 and 252 and improve cooling efficiency.

[0087] (16) According to the second embodiment, the laser chamber 10 includes an inclined member 12c that guides the laser gas that has passed between the first and second discharge electrodes 11a and 11b in a direction approaching the guide portion 28. When viewed in cross section along a plane perpendicular to the Z direction, the surface of the inclined member 12c coincides with a tangent to the first guide surface 281 near the guide surface front end 28a.

[0088] This allows the flow of laser gas to be smoothly transferred from inclined member 12c to guide portion 28, thereby improving the flow of laser gas.

[0089] (17) According to the second embodiment, the angle α2 between the tangent line and the H direction is 4° or less.

[0090] According to this, by suppressing the inclination of the tangent line of first guide surface 281, the flow of laser gas along first guide surface 281 can be improved.

[0091] (18) According to the second embodiment, a straight line inclined at 6° with respect to the H direction passes through the inclined member 12c from the center of the discharge surface 11c of the first discharge electrode 11a, which is closest to the inclined member 12c, facing the second discharge electrode 11b of the first discharge electrode 11a and the second discharge electrode 11b.

[0092] According to this, by ensuring a sufficient distance in the H direction from the discharge surface 11c of the first discharge electrode 11a to the guide surface front end 28a, the flow of the laser gas along the first guide surface 281 can be improved.

[0093] In other respects, the second embodiment is similar to the first embodiment.

[0094] 5.Other 5.1 Manufacturing methods for electronic devices 18 shows the configuration of an exposure system. The exposure system includes a laser device 1a and an exposure device 100. The laser device 1a is configured to output a laser beam LB toward the exposure device 100.

[0095] Exposure apparatus 100 includes an illumination optical system 40 and a projection optical system 41. Illumination optical system 40 illuminates a reticle pattern of a reticle (not shown) placed on a reticle stage RT with laser light LB incident from laser device 1a. Projection optical system 41 reduces and projects the laser light LB 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.

[0096] Exposure apparatus 100 exposes the workpiece with laser light LB reflecting the reticle pattern by synchronously translating reticle stage RT and workpiece table WT. After the reticle pattern is transferred to the semiconductor wafer through the exposure process described above, electronic devices can be manufactured through multiple processes.

[0097] 5.2 Laser Control Processor 30 The laser control processor 30 may be physically configured in the form of hardware to execute the various processes described herein. For example, the laser control processor 30 may be a computer including a memory storing a control program that defines the various processes and a processing device that executes the control program. The control program may be stored in a single memory, or may be stored separately in multiple physically separate memories, with the various processes defined by the control program as a collection of these memories. The processing device may be a general-purpose processing device such as a CPU, or a specific-purpose processing device such as a GPU.

[0098] The laser control processor 30 may be programmed in the form of software to execute the various processes described herein. For example, the laser control processor 30 may be implemented in a dedicated device such as an ASIC or a programmable device such as an FPGA.

[0099] The various processes included in the present disclosure may be performed by a single computer, a single dedicated device, or a single programmable device, or may be performed by cooperation of multiple physically separate computers, multiple dedicated devices, or multiple programmable devices. The various processes may be performed by a combination of at least two of one or more computers, one or more dedicated devices, and one or more programmable devices.

[0100] 5.3 Supplementary Information The above description is intended to be illustrative rather than limiting. Thus, it will be apparent to one skilled in the art that modifications can be made to the disclosed embodiments without departing from the scope of the claims. It will also be apparent to one skilled in the art that the disclosed embodiments can be used in combination.

[0101] 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." Furthermore, it should be construed as including combinations of these with elements other than "A," "B," and "C."

Claims

1. A laser chamber of a discharge excitation gas laser device, first and second discharge electrodes arranged opposite to each other in a direction parallel to a first direction, each of the first and second discharge electrodes extending in a second direction perpendicular to the first direction; a fan disposed in the laser chamber for circulating a laser gas in the laser chamber; a cooling unit disposed in the laser chamber and configured to cool the laser gas; a guide section that rotates the flow direction of the laser gas that has passed between the first and second discharge electrodes in a third direction perpendicular to both the first and second directions around an axis parallel to the second direction and directs the laser gas toward the cooling section, When the laser chamber is viewed in cross section on a plane perpendicular to the second direction, at least a part of a first guide surface extending from a front end of a guide surface that is an end in the first direction on the upstream side of the flow direction of the guide portion to a rear end of a guide surface that is an end in the opposite direction to the first direction on the downstream side, a first imaginary curve whose curvature decreases along the flow direction, the first imaginary curve extending from a first phase angle to a second phase angle of a first imaginary logarithmic spiral, the first imaginary curve having an intersecting angle of 103° between a straight line from the origin and a tangent to the first imaginary curve; a second imaginary curve whose curvature decreases along the flow direction, the second imaginary curve extending from the first phase angle to the second phase angle of a second imaginary logarithmic spiral, the second imaginary curve having an intersecting angle of 96° between a straight line from the origin and a tangent to the second imaginary curve; and extending over a first section corresponding to a phase angle of 90° or more between the first and second virtual logarithmic spirals. The guide portion is disposed in the laser chamber; A laser chamber comprising:

2. 2. The laser chamber of claim 1, When viewed in cross section along a plane perpendicular to the second direction, the first guide surface includes a combination of a plurality of arcs having centers different from each other. Laser chamber.

3. 2. The laser chamber of claim 1, When viewed in cross section on a plane perpendicular to the second direction, the first guide surface includes a combination of a plurality of arcs having centers different from each other and radii increasing along the flow direction. Laser chamber.

4. 2. The laser chamber of claim 1, When viewed in cross section along a plane perpendicular to the second direction, the first guide surface includes a part of an ellipse whose curvature changes along the flow direction. Laser chamber.

5. 2. The laser chamber of claim 1, When viewed in cross section along a plane perpendicular to the second direction, the first guide surface includes a combination of a plurality of arcs having centers different from one another and a common circumtangent thereto. Laser chamber.

6. 2. The laser chamber of claim 1, When viewed in cross section on a plane perpendicular to the second direction, the first guide surface includes a combination of three or more arcs having centers different from one another and a common circumtangent of the arcs having centers adjacent to one another. Laser chamber.

7. 2. The laser chamber of claim 1, the first guide surface extends over a second section including the first section, the second section corresponding to the first phase angle to the second phase angle of the first and second virtual logarithmic spirals; Laser chamber.

8. 8. The laser chamber of claim 7, a front end of the guide surface is located at a position corresponding to the first phase angle, and a rear end of the guide surface is located at a position corresponding to the second phase angle; Laser chamber.

9. 2. The laser chamber of claim 1, the first section is a section from the first phase angle to a third phase angle between the first and second phase angles, and the front end of the guide surface is located at a position corresponding to the first phase angle; Laser chamber.

10. 2. The laser chamber of claim 1, the first section is a section from a third phase angle between the first and second phase angles to the second phase angle, and the rear end of the guide surface is located at a position corresponding to the second phase angle; Laser chamber.

11. 2. The laser chamber of claim 1, the first section is a continuous section; Laser chamber.

12. 2. The laser chamber of claim 1, the first section includes a plurality of discontinuous sections in which the sum of the magnitudes of the phase angles is 90° or more; Laser chamber.

13. 13. The laser chamber of claim 12, a front end of the guide surface is located at a position corresponding to the first phase angle, and a rear end of the guide surface is located at a position corresponding to the second phase angle; Laser chamber.

14. 2. The laser chamber of claim 1, the guide portion includes a second guide surface extending from a rear end of the guide surface downstream in the flow direction, the cooling unit includes first and second cooling pipes arranged in a fourth direction perpendicular to the second direction and facing the second guide surface, and an angle between the fourth direction and the second guide surface is 5° or less. Laser chamber.

15. 15. The laser chamber of claim 14, a distance between the rear end of the guide surface and the first cooling pipe is shorter than a distance between the rear end of the guide surface and the second cooling pipe; a distance between the second guide surface and the first cooling pipe is longer than a distance between the second guide surface and the second cooling pipe; Laser chamber.

16. 2. The laser chamber of claim 1, a tilting member that guides the laser gas that has passed between the first and second discharge electrodes in a direction approaching the guide portion, When viewed in cross section along a plane perpendicular to the second direction, a surface of the inclined member coincides with a tangent to the first guide surface in the vicinity of the front end of the guide surface. Laser chamber.

17. 17. The laser chamber of claim 16, the angle between the tangent and the third direction is 4° or less; Laser chamber.

18. 17. The laser chamber of claim 16, a straight line inclined at 6° with respect to the third direction from a center of a discharge surface of a first discharge electrode of the first and second discharge electrodes that is closer to the inclined member and that faces the second discharge electrode passes through the inclined member; Laser chamber.

19. an optical resonator; a laser chamber located in an optical path of the optical resonator, first and second discharge electrodes arranged opposite to each other in a direction parallel to a first direction, each of the first and second discharge electrodes extending in a second direction perpendicular to the first direction; a fan disposed in the laser chamber for circulating a laser gas in the laser chamber; a cooling unit disposed in the laser chamber and configured to cool the laser gas; a guide section that rotates the flow direction of the laser gas that has passed between the first and second discharge electrodes in a third direction perpendicular to both the first and second directions around an axis parallel to the second direction and directs the laser gas toward the cooling section, When the laser chamber is viewed in cross section on a plane perpendicular to the second direction, at least a part of a first guide surface extending from a front end of a guide surface that is an end in the first direction on the upstream side of the flow direction of the guide portion to a rear end of a guide surface that is an end in the opposite direction to the first direction on the downstream side, a first imaginary curve whose curvature decreases along the flow direction, the first imaginary curve extending from a first phase angle to a second phase angle of a first imaginary logarithmic spiral, the first imaginary curve having an intersecting angle of 103° between a straight line from the origin and a tangent to the first imaginary curve; a second imaginary curve whose curvature decreases along the flow direction, the second imaginary curve extending from the first phase angle to the second phase angle of a second imaginary logarithmic spiral, the second imaginary curve having an intersecting angle of 96° between a straight line from the origin and a tangent to the second imaginary curve; and extending over a first section corresponding to a phase angle of 90° or more between the first and second virtual logarithmic spirals. The guide portion is disposed in the laser chamber; the laser chamber including: A discharge excitation gas laser device comprising:

20. A method for manufacturing an electronic device, comprising: an optical resonator; a laser chamber located in an optical path of the optical resonator, first and second discharge electrodes arranged opposite to each other in a direction parallel to a first direction, each of the first and second discharge electrodes extending in a second direction perpendicular to the first direction; a fan disposed in the laser chamber for circulating a laser gas in the laser chamber; a cooling unit disposed in the laser chamber and configured to cool the laser gas; a guide section that rotates the flow direction of the laser gas that has passed between the first and second discharge electrodes in a third direction perpendicular to both the first and second directions around an axis parallel to the second direction and directs the laser gas toward the cooling section, When the laser chamber is viewed in cross section on a plane perpendicular to the second direction, at least a part of a first guide surface extending from a front end of a guide surface that is an end in the first direction on the upstream side of the flow direction of the guide portion to a rear end of a guide surface that is an end in the opposite direction to the first direction on the downstream side, a first imaginary curve whose curvature decreases along the flow direction, the first imaginary curve extending from a first phase angle to a second phase angle of a first imaginary logarithmic spiral, the first imaginary curve having an intersecting angle of 103° between a straight line from the origin and a tangent to the first imaginary curve; a second imaginary curve whose curvature decreases along the flow direction, the second imaginary curve extending from the first phase angle to the second phase angle of a second imaginary logarithmic spiral, the second imaginary curve having an intersecting angle of 96° between a straight line from the origin and a tangent to the second imaginary curve; and extending over a first section corresponding to a phase angle of 90° or more between the first and second virtual logarithmic spirals. The guide portion is disposed in the laser chamber; the laser chamber including: A laser beam is generated by a discharge excitation gas laser apparatus comprising: outputting the laser light to an exposure device; In order to manufacture the electronic device, the laser light is exposed onto a photosensitive substrate in the exposure apparatus. A method for manufacturing an electronic device, comprising:

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