Laser system and method of manufacturing electronic device

Abstract

To provide a laser system in which a plurality of pulse laser light beams emitted by the plurality of pulse laser devices may be laser beams suitable for exposure.SOLUTION: A system comprises: a first pulse laser device which emits first pulse laser beams in a predetermined cycle; a second pulse laser device which emits second pulse laser beams in the predetermined cycle; a first polygon mirror which reflects the first pulse laser beams and the second pulse laser beams; and a processor which controls the first pulse laser device, the second pulse laser device, and the first polygon mirror so that the first pulse laser beam and the second pulse laser beam are emitted with a shift of 1 / 2 of the predetermined cycle and optical paths of the first pulse laser beam light and second pulse laser beam reflected by the first polygon mirror are oriented in a first direction and overlap at least partially with each other.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to laser systems and methods for manufacturing electronic devices. [Background technology]

[0002] In recent years, semiconductor exposure equipment has been required to improve its 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, gas laser devices used for exposure include KrF excimer laser devices that output laser light with a wavelength of approximately 248 nm and ArF excimer laser devices that output laser light with a wavelength of approximately 193 nm.

[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] US Patent Application Publication No. 2023004091 [Patent Document 2] Chinese Utility Model No. 219143208 [Patent Document 3] Summary of the specification of U.S. Patent No. 5,387,211

[0005] A laser system according to an aspect of the present disclosure may include a first pulse laser device that emits a first pulse laser beam at a predetermined period, a second pulse laser device that emits a second pulse laser beam at a predetermined period, a first polygon mirror that reflects the first pulse laser beam and the second pulse laser beam, and a processor that controls the first pulse laser device, the second pulse laser device, and the first polygon mirror so that the first pulse laser beam and the second pulse laser beam are emitted with a shift of one-half of the predetermined period, and the optical paths of the first pulse laser beam and the second pulse laser beam reflected by the first polygon mirror face in a first direction and at least partially overlap with each other.

[0006] Furthermore, a method for manufacturing an electronic device according to an aspect of the present disclosure may include outputting to an exposure device the first pulsed laser beam and the second pulsed laser beam generated by a laser system including: a first pulsed laser device that emits a first pulsed laser beam at a predetermined period; a second pulsed laser device that emits a second pulsed laser beam at the predetermined period; a first polygon mirror that reflects the first pulsed laser beam and the second pulsed laser beam; and a processor that controls the first pulsed laser device, the second pulsed laser device, and the first polygon mirror so that the first pulsed laser beam and the second pulsed laser beam are emitted with an offset of half the predetermined period and the optical paths of the first pulsed laser beam and the second pulsed laser beam reflected by the first polygon mirror face in a first direction and at least partially overlap each other; and exposing a photosensitive substrate in the exposure device to the first pulsed laser beam and the second pulsed laser beam to manufacture an electronic device. [Brief explanation of the drawings]

[0007] 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 schematic diagram showing an example of the overall configuration of an electronic device manufacturing apparatus. [Figure 2] FIG. 2 is a schematic diagram showing an example of the overall schematic configuration of a laser system of a comparative example. [Figure 3]FIG. 3 is a schematic diagram showing an example of the general configuration of a pulse laser device provided in a laser system of a comparative example. [Figure 4] FIG. 4 is a timing chart showing the relationship between the emission timing of the first pulse laser beam and the emission timing of the second pulse laser beam. [Figure 5] FIG. 5 is a timing chart showing the emission timing of the pulse combined light obtained by combining the first pulse laser light and the second pulse laser light. [Figure 6] FIG. 6 is a schematic diagram showing an example of the schematic configuration of the laser system of the first embodiment. [Figure 7] FIG. 7 is a schematic diagram showing an example of the schematic configuration of a beam steering device. [Figure 8] FIG. 8 is a schematic diagram showing an example of the schematic configuration of a beam measuring instrument. [Figure 9] FIG. 9 is a schematic diagram showing an example of the schematic configuration of a laser system according to a modified example of the first embodiment. [Figure 10] FIG. 10 is a schematic diagram showing an example of the schematic configuration of a laser system according to the second embodiment. [Figure 11] FIG. 11 is a timing chart showing the relationship between the emission timings of the first to fourth pulse laser beams. [Figure 12] FIG. 12 is a timing chart showing the relationship between the emission timings of the pulse combined light obtained by combining the first pulse laser beam and the second pulse laser beam and the pulse combined light obtained by combining the third pulse laser beam and the fourth pulse laser beam. [Figure 13] FIG. 13 is a timing chart showing the emission timing of the pulse combined light obtained by combining the first to fourth pulse laser light. [Figure 14] FIG. 14 is a schematic diagram showing an example of the schematic configuration of a laser system according to a modified example of the second embodiment. Embodiment

[0008] 1. Explanation of the electronic device manufacturing equipment used in the exposure process of electronic devices 2. Description of the laser system of the comparative example 2.1 Configuration 2.2 Operation 2.3 Challenges 3. Description of the laser system of embodiment 1 3.1 Configuration 3.2 Operation 3.3 Actions and Effects 3.4 Variations 4. Description of the laser system of embodiment 2 4.1 Configuration 4.2 Operation 4.3 Actions and Effects 4.4 Variations

[0009] 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.

[0010] 1. Explanation of the electronic device manufacturing equipment used in the exposure process of electronic devices FIG. 1 is a schematic diagram showing an example of the overall configuration of an electronic device manufacturing apparatus used in an exposure process for electronic devices. As shown in FIG. 1, the manufacturing apparatus used in the exposure process includes a laser system 100 and an exposure apparatus 200. The exposure apparatus 200 includes an illumination optical system 210, which includes multiple mirrors 211, 212, and 213, and a projection optical system 220. The illumination optical system 210 illuminates a reticle pattern on a reticle stage RT with laser light incident from the laser system 100. The projection optical system 220 reduces and projects the laser light transmitted through the reticle onto a workpiece (not shown) placed on a workpiece table WT. The workpiece is a photosensitive substrate such as a semiconductor wafer coated with photoresist. The exposure apparatus 200 exposes the workpiece with laser light reflecting the reticle pattern by synchronously translating the reticle stage RT and the workpiece table WT. Semiconductor devices, which are electronic devices, can be manufactured by transferring a device pattern onto a semiconductor wafer using the exposure process described above.

[0011] 2. Description of the laser system of the comparative example 2.1 Configuration A laser system of a comparative example will be described. Note that 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] 2 is a schematic diagram showing an example of the overall configuration of a laser system 100 of this example. The laser system 100 includes a first pulse laser device 120a and a second pulse laser device 120b. The first pulse laser device 120a and the second pulse laser device 120b have the same configuration and include a laser oscillator 130 which is a master oscillator and an amplifier 160 which is a power oscillator. The first pulse laser device 120a and the second pulse laser device 120b emit pulse laser beams L1 and L2 of a predetermined period.

[0013] The first pulse laser device 120a and the second pulse laser device 120b are, for example, ArF excimer laser devices that use a mixed gas containing argon (Ar), fluorine (F2), and neon (Ne). The ArF excimer laser device emits laser light with a center wavelength of approximately 193.4 nm. The first pulse laser device 120a and the second pulse laser device 120b may also be, for example, KrF excimer laser devices that use a mixed gas containing krypton (Kr), F2, and Ne. The KrF excimer laser device emits laser light with a center wavelength of approximately 248.3 nm.

[0014] The laser system 100 further includes a beam combiner 150 that guides the first pulse laser beam L1 and the second pulse laser beam L2 to the same optical path, and reflection mirrors 170a and 170b that reflect the first pulse laser beam L1 from the first pulse laser device 120a and the second pulse laser beam L2 from the second pulse laser device 120b toward the beam combiner 150.

[0015] The beam combiner 150 outputs the first pulse laser beam L1 and the second pulse laser beam L2, which are incident via the reflecting mirrors 170a and 170b, onto the same optical path. The beam combiner 150 may perform spatial beam combining or polarization beam combining of the first pulse laser beam L1 and the second pulse laser beam L2.

[0016] The processor 105 is a processing device including a storage device that stores a control program and a CPU (Central Processing Unit) that executes the control program. The processor 105 is specially configured or programmed to execute various processes included in the present disclosure. The first and second pulse laser devices 120a and 120b are controlled by the processor 105, which emits the first and second pulse laser beams L1 and L2 with a shift of half a predetermined period. Therefore, the first and second pulse laser beams L1 and L2 are emitted alternately. The optical paths of the first and second pulse laser beams L1 and L2 are overlapped by the beam combiner 150, and the laser system 100 emits pulse laser beams at a repetition rate twice that of a single pulse laser device.

[0017] In this specification, the pulsed laser beam emitted from a plurality of pulsed laser devices is referred to as pulsed combined beam when at least a portion of the optical paths of the pulsed laser beams are overlapped and the pulsed laser beams travel in the same direction. Therefore, the pulsed laser beam output from the beam combiner 150, which is composed of the first pulsed laser beam L1 and the second pulsed laser beam L2, is referred to as pulsed combined beam L. 12 is.

[0018] Next, first pulse laser device 120a and second pulse laser device 120b, which have the same configuration, are referred to as pulse laser device 120, and their configurations are shown in Fig. 3. Pulse laser device 120 mainly includes housing 110, laser oscillator 130 serving as a master oscillator arranged in the internal space of housing 110, optical transmission unit 141, amplifier 160 serving as a power oscillator, detection unit 153, display unit 180, and processor 190.

[0019] The laser oscillator 130 includes a chamber device CH1, a charger 41, a pulse power module 43, a line narrowing module 60, and an output coupling mirror 70 as its main components.

[0020] 3 shows the internal configuration of the chamber apparatus CH1 as viewed from a direction substantially perpendicular to the propagation direction of the laser light. The chamber apparatus CH1 mainly comprises a housing 30, a pair of windows 31a and 31b, a pair of electrodes 32a and 32b, an insulating section 33, a feedthrough 34, and an electrode holder section 36.

[0021] The housing 30 has a laser gas sealed in its internal space. The internal space is a space where light is generated by excitation of the laser medium in the laser gas. This light propagates to the windows 31a and 31b.

[0022] Window 31a is arranged on the front wall of housing 30 in the propagation direction of laser light from laser system 100 to exposure device 200, and window 31b is arranged on the rear wall of housing 30 in the propagation direction. Windows 31a and 31b are made of, for example, a calcium fluoride substrate, and the surfaces of windows 31a and 31b facing the inside and outside of housing 30 are flat. Note that windows 31a and 31b are not limited to calcium fluoride substrates as long as they are capable of transmitting laser light.

[0023] The electrodes 32a and 32b are arranged opposite each other in the internal space of the housing 30, and the longitudinal direction of the electrodes 32a and 32b is aligned with the propagation direction of light generated by a high voltage applied between the electrodes 32a and 32b. The discharge space between the electrodes 32a and 32b in the housing 30 is sandwiched between the windows 31a and 31b. The electrodes 32a and 32b are discharge electrodes for exciting the laser medium by glow discharge. In this example, the electrode 32a is the cathode, and the electrode 32b is the anode.

[0024] The electrode 32a is supported by an insulating part 33. The insulating part 33 closes an opening formed in the housing 30. The insulating part 33 includes an insulator. A feedthrough 34 made of a conductive member is also disposed in the insulating part 33. The feedthrough 34 applies a voltage supplied from a pulse power module 43 to the electrode 32a. The electrode 32b is supported by an electrode holder part 36 and is electrically connected to the electrode holder part 36.

[0025] Charger 41 is a DC power supply device that charges a capacitor (not shown) provided inside PPM 43 at a predetermined voltage. Charger 41 is located outside housing 30 and connected to PPM 43. PPM 43 includes a switch (not shown) controlled by processor 190. When the switch is turned on by this control, PPM 43 boosts the voltage applied from charger 41 to generate a pulsed high voltage and applies this high voltage to electrodes 32a and 32b. When the high voltage is applied, a discharge occurs between electrodes 32a and 32b. The energy of this discharge excites the laser medium inside housing 30. When the excited laser gas transitions to the ground state, light is emitted. The emitted light passes through windows 31a and 31b and exits housing 30. The windows 31 a and 31 b are tilted at a Brewster angle with respect to the propagation direction of the laser beam so as to suppress reflection of P-polarized light of the laser beam, and in this example, are tilted with respect to a direction perpendicular to the propagation direction of the laser beam and the direction in which the electrodes 32 a and 32 b face each other. Therefore, the laser beam emitted from the chamber apparatus CH1 contains a predetermined linearly polarized light whose polarization direction is perpendicular to the direction in which the electrodes 32 a and 32 b face each other, and linearly polarized light whose polarization direction is different from the polarization direction of the predetermined linearly polarized light is reduced from the laser beam.

[0026] The line narrowing module 60 includes a housing 65, a prism 61, a grating 63, and a rotation stage (not shown) that are arranged in the internal space of the housing 65. An opening is formed in the housing 65, and the housing 65 is connected to the rear side of the housing 30 via the opening.

[0027] Prism 61 expands the beam width of light emitted from window 31b and makes the light incident on grating 63. Prism 61 also reduces the beam width of light reflected from grating 63 and returns the light to the internal space of housing 30 via window 31b. Prism 61 is supported on a rotation stage and rotates by the rotation stage. Rotation of prism 61 changes the angle of incidence of light with respect to grating 63, making it possible to select the wavelength of light that returns from grating 63 to housing 30 via prism 61. While FIG. 3 shows an example in which one prism 61 is arranged, two or more prisms may be arranged.

[0028] The surface of the grating 63 is made of a highly reflective material, and numerous grooves are provided at regular intervals on the surface. The grating 63 is a dispersive optical element. The cross-sectional shape of each groove is, for example, a right-angled triangle. Light incident on the grating 63 from the prism 61 is reflected by these grooves and diffracted in a direction according to the wavelength of the light. The grating 63 is Littrow-oriented so that the angle of incidence of the light incident on the grating 63 from the prism 61 matches the angle of diffraction of the diffracted light of the desired wavelength. This allows the light of the desired wavelength to be returned to the housing 30 via the prism 61.

[0029] The output coupling mirror 70 transmits a portion of the laser light emitted from the window 31a and reflects the other portion back through the window 31a into the internal space of the housing 30. The output coupling mirror 70 is fixed to a holder (not shown) and is disposed in the internal space of the housing 110.

[0030] The grating 63 and the output coupling mirror 70, which are provided on either side of the housing 30, form a Fabry-Perot resonator, and the housing 30 is disposed on the optical path of the resonator.

[0031] The optical transmission unit 141 mainly includes high-reflection mirrors 141b and 141c. The high-reflection mirrors 141b and 141c are fixed to holders (not shown) with their respective tilt angles adjusted, and are arranged in the internal space of the housing 110. The high-reflection mirrors 141b and 141c highly reflect the laser light. The high-reflection mirrors 141b and 141c are arranged on the optical path of the laser light that passes through the output coupling mirror 70. The laser light is reflected by the high-reflection mirrors 141b and 141c and propagates to the rear mirror 371 of the amplifier 160. At least a portion of this laser light passes through the rear mirror 371.

[0032] The amplifier 160 amplifies the energy of the laser beam output from the laser oscillator 130. The basic configuration of the amplifier 160 is generally the same as that of the laser oscillator 130. Therefore, components similar to those of the laser oscillator 130 are denoted by the same reference numerals and will not be described in detail unless otherwise specified. The electrodes 32a and 32b generate a discharge for amplifying the laser beam from the laser oscillator 130. The direction in which the electrodes 32a and 32b face each other is perpendicular to the direction in which the linear polarization of the laser beam from the laser oscillator 130 is changed. The windows 31a and 31b are tilted with respect to the polarization direction of the predetermined linear polarization so that the linearly polarized laser beam enters as P-polarized light and the angle of incidence of the laser beam is Brewster's angle. Therefore, the laser beam output from the chamber apparatus CH2 contains the predetermined linearly polarized light, and linearly polarized light having a polarization direction different from the polarization direction of the predetermined linearly polarized light is reduced from the laser beam.

[0033] Furthermore, the amplifier 160 differs from the laser oscillator 130 in that it does not include the line narrowing module 60 but includes a rear mirror 371. The rear mirror 371 is provided between the high-reflection mirror 141c and the window 31b. The rear mirror 371 transmits a portion of the laser light from the laser oscillator 130 toward the discharge space between the electrodes 32a and 32b, and reflects a portion of the laser light amplified in the chamber device CH2 back toward the discharge space of the chamber device CH2.

[0034] The output coupling mirror 370 is disposed on the opposite side of the chamber device CH2 from the rear mirror 371. The output coupling mirror 370 reflects a portion of the laser light from the chamber device CH2 and transmits another portion of the laser light. Therefore, the surface of the output coupling mirror 370 facing the chamber device CH2 is coated with a partially reflective film having a predetermined reflectance.

[0035] The detection unit 153 mainly includes a beam splitter 153b and an optical sensor 153c.

[0036] Beam splitter 153b is disposed on the optical path of the laser light passing through output coupling mirror 370. Beam splitter 153b transmits the laser light passing through output coupling mirror 370 toward output window 173 with high transmittance, and also reflects a portion of the laser light toward the light receiving surface of optical sensor 153c.

[0037] Optical sensor 153c measures the pulse energy of the laser light incident on the light-receiving surface of optical sensor 153c. Optical sensor 153c is electrically connected to processor 190 and outputs a signal indicating the measured pulse energy to processor 190. Processor 190 controls the voltage applied to electrodes 32a and 32b of amplifier 160 based on the signal.

[0038] An exit window 173 is provided on the opposite side of the output coupling mirror 370 with respect to the beam splitter 153b of the detection unit 153. The exit window 173 is provided on the wall of the housing 110. The light that passes through the beam splitter 153b is emitted from the exit window 173 to the exposure device 200 outside the housing 110. This laser light is, for example, pulsed laser light with a center wavelength of 193.4 nm.

[0039] The display unit 180 is a monitor that displays the state of control by the processor 190 based on a signal from the processor 190. The display unit 180 may be disposed outside the housing 110.

[0040] Processor 190 of the present disclosure is a processing device similar in configuration to processor 105. Processor 190 is specially configured or programmed to perform various processes included in the present disclosure.

[0041] 2.2 Operation Next, the operation of the pulse laser device 120 will be described.

[0042] When the pulsed laser device 120 emits laser light, the processor 190 receives a signal indicating the target energy Et and a light emission trigger signal from an exposure processor (not shown) of the exposure device 200, for example, via the processor 105. The target energy Et is a target value for the energy of the laser light used in the exposure process. The processor 190 sets a predetermined charging voltage for the charger 41 of the amplifier 160 so that the energy E becomes the target energy Et, and turns on the switch of the pulse power module 43 of the laser oscillator 130 in synchronization with the light emission trigger signal. This causes the pulse power module 43 to generate a pulsed high voltage from the electrical energy stored in the charger 41, and the high voltage is applied between the electrodes 32a and 32b of the laser oscillator 130. When the high voltage is applied, a discharge occurs between the electrodes 32a and 32b, and the laser medium contained in the laser gas between the electrodes 32a and 32b is excited, emitting light when the laser medium returns to its ground state. The emitted light resonates between the grating 63 and the output coupling mirror 70 of the laser oscillator 130, and is amplified each time it passes through the discharge space in the internal space of the housing 30, causing laser oscillation. The laser light contains a predetermined linear polarization, and when it passes through windows 31a and 31b, linear polarization with a polarization direction different from the predetermined linear polarization is reduced from the laser light. A portion of the laser light passes through the output coupling mirror 70 and is reflected by high-reflection mirrors 141b and 141c, and the laser light propagates into the amplifier 160. In the amplifier 160, the laser light passes through the rear mirror 371 and windows 31a and 31b and propagates into the housing 30 of the amplifier 160.

[0043] The processor 190 turns on the switch of the pulse power module 43 of the amplifier 160 so that a discharge occurs when the laser light from the laser oscillator 130 propagates into the discharge space in the housing 30 of the amplifier 160. That is, the processor 190 controls the pulse power module 43 so that a high voltage is applied to the electrodes 32 a, 32 b of the amplifier 160 after a predetermined delay time has elapsed since the switch of the pulse power module 43 was turned on.

[0044] As a result, the laser light incident on amplifier 160 is amplified in amplifier 160. Furthermore, the laser light propagated into the internal space of housing 30 propagates to output coupling mirror 370 via window 31a as described above, and is reflected by output coupling mirror 370. The laser light reflected by output coupling mirror 370 propagates into the internal space of housing 30 via window 31a and exits from window 31b. The light exiting window 31b is reflected by rear mirror 371 and propagates into the internal space of housing 30 via window 31b. In this way, laser light of a predetermined wavelength travels back and forth between rear mirror 371 and output coupling mirror 370. The laser light contains a predetermined linearly polarized light, and linearly polarized light with a polarization direction different from the polarization direction of the predetermined linearly polarized light is reduced from the laser light when it passes through windows 31a and 31b. Furthermore, the laser light is amplified each time it passes through the discharge space inside housing 30.

[0045] A portion of the laser light from the chamber device CH2 of the amplifier 160 passes through the output coupling mirror 370 and propagates to the beam splitter 153b.

[0046] A portion of the amplified laser light that has propagated to the beam splitter 153b passes through the beam splitter 153b and the exit window 173 and propagates to the exposure device 200, and the other portion is reflected by the beam splitter 153b and propagates to the optical sensor 153c.

[0047] The optical sensor 153c measures the energy E of the received amplified laser beam. The optical sensor 153c outputs a signal indicating the measured energy E to the processor 190. The processor 190 feedback-controls the charging voltage of the charger 41 so that the difference ΔE between the energy E and the target energy Et falls within an allowable range. The laser beam whose difference ΔE falls within the allowable range passes through the beam splitter 153b and the exit window 173 and is emitted.

[0048] Returning to Fig. 2, the operation of the laser system 100 of the comparative example will be further described. Fig. 4 is a timing chart showing the relationship between the emission timing of the first pulse laser beam L1 from the first pulse laser device 120a and the emission timing of the second pulse laser beam L2 from the second pulse laser device 120b in this example. The horizontal axis represents time, and the vertical axis represents the intensity of the pulse laser beam. This also applies to the other timing charts described below.

[0049] As described above, the first pulse laser device 120a and the second pulse laser device 120b emit first and second pulse laser beams L1, L2 at a predetermined period, and the first and second pulse laser beams L1, L2 are shifted from each other by half the predetermined period. If the predetermined period for emitting the first and second pulse laser beams L1, L2 is T, then the phases of the first and second pulse laser beams L1, L2 are shifted from each other by half a period T / 2. The processor 105 controls the first and second pulse laser devices 120a, 120b to alternately emit the first and second pulse laser beams L1, L2 as described above.

[0050] The first pulse laser beam L1 emitted from the first pulse laser device 120a is reflected by a reflecting mirror 170a and enters the beam combiner 150. The second pulse laser beam L2 emitted from the second pulse laser device 120b is reflected by a reflecting mirror 170b and enters the beam combiner 150. The beam combiner 150 emits the first pulse laser beam L1 and the second pulse laser beam L2 along the same optical path.

[0051] FIG. 5 shows the pulsed combined light L emerging from the beam combiner 150. 121 is a timing chart showing the emission timing of the first pulse laser beam L1 emitted from the first pulse laser device 120a and the second pulse laser beam L2 emitted from the second pulse laser device 120b. The first pulse laser beam L1 emitted from the first pulse laser device 120a and the second pulse laser beam L2 emitted from the second pulse laser device 120b are alternately emitted from the beam combiner 150. In other words, the beam combiner 150 outputs a pulse combined beam L, which is a train of pulse laser beams with a period of T / 2. 12 is emitted.

[0052] In this way, the laser system 100 emits pulsed combined light L at a repetition rate twice that of a single pulse laser device. 12 is emitted.

[0053] 2.3 Challenges As the throughput of the exposure apparatus 200 increases, there is an increasing demand for higher output from the laser system 100, which is the light source. However, if the beam combiner 150 uses a spatial beam combining method, the combined beam size or beam divergence may increase. If the design of the exposure apparatus is not changed, an increase in the beam size or beam divergence may result in a situation where part of the beam becomes unusable. Therefore, there is a need to suppress the beam size or beam divergence so as not to change the design of the exposure apparatus. Furthermore, even when designing a new exposure apparatus, there is a need to suppress the beam size or beam divergence to prevent the exposure apparatus from becoming larger and to facilitate the design and manufacture of the exposure apparatus.

[0054] Furthermore, if the beam combiner 150 is a polarized beam combining type, two different polarized lights will be provided to the exposure tool, which may be inappropriate for exposure.

[0055] In the following embodiment, a laser system is exemplified in which a plurality of pulsed laser beams emitted from a plurality of pulsed laser devices can become laser beams suitable for exposure.

[0056] 3. Description of the laser system of embodiment 1 The following describes the laser system 100 of the embodiment 1. Note that the same components as those described above are given the same reference numerals, and redundant descriptions will be omitted unless otherwise specified.

[0057] 3.1 Configuration Fig. 6 is a schematic diagram showing an example of the overall configuration of a laser system 100 according to the first embodiment. As shown in Fig. 6, the laser system 100 according to the present embodiment differs from the laser system 100 according to the comparative example mainly in that it includes a first polygon mirror 360 that reflects the first pulse laser beam L1 and the second pulse laser beam L2, and a processor 350 that controls the emission timing of the first pulse laser beam L1, the emission timing of the second pulse laser beam L2, and the rotation angle of the first polygon mirror 360 so that the first pulse laser beam L1 and the second pulse laser beam L2 are reflected in the same first direction. The first and second pulse laser devices 120a and 120b emit first and second pulse laser beams L1 and L2 having the same frequency, similar to the comparative example.

[0058] The first pulse laser device 120a and the second pulse laser device 120b may be configured with a laser oscillator 130, which is a master oscillator, and an amplifier 160, which is a power oscillator, as in the comparative example, or may be configured with only the laser oscillator 130 without the amplifier 160.

[0059] The laser system 100 of this embodiment includes a processor 350 instead of the processor 105. The processor 350 is a processing device similar to the processor 105. The processor 350 is specially configured or programmed to execute various processes included in this embodiment. The processor 350 is also electrically connected to the processors 190 included in the first and second pulse laser devices 120a and 120b and to an exposure processor (not shown) in the exposure device 200, and transmits and receives various signals between the respective processors.

[0060] The first polygon mirror 360 includes N reflecting mirrors, each of which has a constant angle between adjacent reflecting mirrors. N is a natural number equal to or greater than 3. In this embodiment, N is 4. The first polygon mirror 360 is connected to a drive unit (not shown) and rotates at a substantially constant speed around a central axis C. When the repetition frequency of the first pulse laser beam L1 emitted from the first pulse laser device 120a and the second pulse laser beam L2 emitted from the second pulse laser device 120b is X [Hz], the number of rotations per unit time of the first polygon mirror 360 is preferably X / N [rps]. In this embodiment, since N=4, the number of rotations per unit time of the first polygon mirror 360 is X / 4 [rps]. However, the number of rotations per unit time of the first polygon mirror 360 including N reflecting mirrors is not limited to X / N [rps] and may be, for example, 2X / N [rps]. The drive unit of the first polygon mirror 360 is electrically connected to the processor 350 , and the rotation speed of the first polygon mirror 360 is controlled by the processor 350 .

[0061] The angle of incidence θ of the first pulse laser beam L1 incident on the first polygon mirror 360 from the first pulse laser device 120a and the angle of incidence φ of the second pulse laser beam L2 incident on the first polygon mirror 360 from the second pulse laser device 120b are preferably the same. When the angles of incidence θ and φ are the same, and the first polygon mirror 360 includes N reflecting mirrors, the angle of incidence is preferably 360 / 4N°. In this embodiment, since N=4, the angle of incidence is θ=φ=22.5°.

[0062] Each reflecting mirror of the first polygon mirror 360 is made of, for example, a multilayer film. In this case, each reflecting mirror is formed so as to reflect the first and second pulsed laser beams L1 and L2 from the first and second pulsed laser devices 120a and 120b with high reflectivity when they are incident at a predetermined angle of incidence. Therefore, in this example, each reflecting mirror preferably has the highest reflectivity at an incident angle of 22.5°.

[0063] The first pulsed laser beam L1 and the second pulsed laser beam L2 reflected by the first polygon mirror 360 propagate in the same first direction. Furthermore, at least a part of the optical paths of the first pulsed laser beam L1 and the second pulsed laser beam L2 reflected by the first polygon mirror 360 overlap. Therefore, the first polygon mirror 360 outputs a pulsed combined beam L 12 is emitted.

[0064] The laser system 100 of this embodiment further includes beam steering devices 310a and 310b that are provided in the optical paths of the first and second pulse laser beams L1 and L2 that are emitted from the first pulse laser device 120a and the second pulse laser device 120b and enter the first polygon mirror 360, and that adjust the optical paths of the first and second pulse laser beams L1 and L2. In other words, the beam steering devices 310a and 310b are provided upstream of the first polygon mirror 360.

[0065] Because the beam steering devices 310a and 310b have the same configuration, the beam steering devices 310a and 310b will be described as the beam steering device 310. Fig. 7 is a schematic diagram showing an example of the general configuration of the beam steering device 310. The beam steering device 310 includes reflecting mirrors 420a and 420b, and actuators 410a and 410b that change the orientations of the reflecting mirrors 420a and 420b, respectively. The actuators 410a and 410b are electrically connected to the processor 350, and at least one of their positions and angles is controlled by the processor 350 to adjust the optical paths of the first and second pulsed laser beams L1 and L2 emitted from the beam steering device 310.

[0066] The beam steering device 310 may be provided between one of the first pulse laser device 120a and the second pulse laser device 120b and the first polygon mirror 360, and may not be provided on the optical path of the other. Furthermore, when the first and second pulse laser beams L1 and L2 are emitted from the first and second pulse laser devices 120a and 120b in appropriate directions, the laser system 100 may not include the beam steering device 310.

[0067] In this embodiment, the laser system 100 includes a mirror 331 that reflects the second pulse laser beam L2, and the second pulse laser beam L2 emitted from the second pulse laser device 120b and passed through the beam steering device 310b is reflected by the mirror 331 and enters the first polygon mirror 360.

[0068] The laser system 100 of this embodiment also includes a beam measuring instrument 320 that measures at least one of the beam position and pointing (direction) of the first and second pulsed laser beams L1 and L2 reflected by the first polygon mirror 360.

[0069] 8 is a schematic diagram showing an example of the general configuration of the beam measurement instrument 320. The beam measurement instrument 320 includes a beam splitter 430 and an optical sensor 440. The beam splitter 430 splits the pulsed combined light L 12 The beam measuring instrument 320 preferably further measures pulse energy, power, wavelength, spectrum, etc.

[0070] The processor 350 controls the beam steering devices 310a and 310b based on the measurement results of the beam measuring device 320 so that the optical path of the first pulsed laser beam L1 reflected by the first polygon mirror 360 and the optical path of the second pulsed laser beam L2 reflected by the first polygon mirror 360 become closer to each other. Furthermore, the processor 350 controls the first pulsed laser device 120a, the second pulsed laser device 120b, the beam steering devices 310a, the beam steering devices 310b, and the first polygon mirror 360 based on the measurement results of the beam measuring device 320, and adjusts the pulsed combined beam L to have an optimal beam power for the exposure apparatus 200. 12 Adjust the intensity and light path.

[0071] The beam measuring instrument 320 may be provided outside the laser system 100. Furthermore, the laser system 100 does not necessarily have to include the beam measuring instrument 320.

[0072] In this embodiment, the laser system 100 generates pulsed combined light L 12 The pulsed combined light L emitted from the first polygon mirror 360 is reflected by a mirror 332. 12 is reflected by mirror 332 and enters beam measuring instrument 320.

[0073] In this embodiment, the pulsed combined light L 12 A pulse stretcher 325 that temporally widens the pulse widths of the first pulsed laser beam L1 and the second pulsed laser beam L2 is provided on the optical path along which the pulsed combined beam L propagates. That is, the pulse stretcher 325 is provided downstream of the first polygon mirror 360. The pulse stretcher 325, for example, 12 The pulsed combined light L is placed on the optical path of 12 A beam splitter reflects and splits a part of the pulsed combined light L 12 The pulsed combined light L is reflected multiple times and transmitted through the beam splitter. 12 The delayed pulsed combined light L 12 is the pulsed combined light L transmitted through the beam splitter 12 The light is returned to the same optical path as the

[0074] The pulse stretcher 325 may be provided upstream of the first polygon mirror 360, but is preferably provided downstream of the first polygon mirror 360. When the pulse stretcher 325 is provided upstream of the first polygon mirror 360, the first and second pulse laser beams L1, L2, whose temporal pulse widths have been expanded, are reflected by the rotating first polygon mirror 360, which makes it easier for the optical paths of the reflected first and second pulse laser beams L1, L2 to deviate from each other. In contrast, when the pulse stretcher 325 is provided downstream of the first polygon mirror 360, the first and second pulse laser beams L1, L2, whose temporal pulse widths have not yet been expanded, are reflected by the first polygon mirror 360, making it easier for the first pulse laser beam L1 and the second pulse laser beam L2 to be reflected in the same direction. The pulse stretcher 325 is not necessarily provided.

[0075] In this embodiment, as shown in FIG. 6, the emission direction of the first pulse laser beam L1 emitted from the first pulse laser device 120a and the emission direction of the second pulse laser beam L2 emitted from the second pulse laser device 120b are determined based on the pulse combined beam L consisting of the first and second pulse laser beams L1 and L2 emitted from the laser apparatus 100. 12 By emitting the first pulse laser beam L1 and the second pulse laser beam L2 in this manner, the number of mirrors that reflect the first pulse laser beam L1 and the second pulse laser beam L2 can be reduced, the layout can be made more efficient, and the laser system 100 can be made smaller. However, if the emission direction of the first pulse laser beam L1 emitted from the first pulse laser device 120a and the emission direction of the second pulse laser beam L2 emitted from the second pulse laser device 120b are different from the emission direction of the pulse combined beam L2 emitted from the laser system 100, 12 The direction of emission does not have to be opposite to the direction of emission of the light.

[0076] 3.2 Operation The processor 350 emits first and second pulse laser beams L1 and L2 from the first and second pulse laser devices 120a and 120b in the same manner as in the comparative example. Therefore, the first and second pulse laser beams L1 and L2 are emitted with a shift of half a predetermined period T from each other, as shown in Fig. 4. The optical paths of the first and second pulse laser beams L1 and L2 emitted from the first and second pulse laser devices 120a and 120b are adjusted by the beam steering devices 310a and 310b, and the first and second pulse laser beams L1 and L2 are incident on the first polygon mirror 360 and reflected by the reflecting surface of the first polygon mirror 360.

[0077] Here, it is assumed that the angle formed between the first pulse laser beam L1 incident on the first polygon mirror 360 and the second pulse laser beam L2 incident on the first polygon mirror 360 is 90°. In Fig. 6, the state of the first polygon mirror 360 at the timing when the first pulse laser beam L1 is incident is indicated by a solid line, and the state of the first polygon mirror 360 at the timing when the second pulse laser beam L2 is incident is indicated by a dashed line. The two states of the first polygon mirror 360 are rotated by 45° relative to each other. Furthermore, in this case, when the spatial absolute coordinates of the position where the first pulse laser beam L1 is incident on the first polygon mirror 360 and the spatial absolute coordinates of the position where the second pulse laser beam L2 is incident on the first polygon mirror 360 match, the optical path along which the first pulse laser beam L1 reflected by the first polygon mirror 360 propagates and the optical path along which the second pulse laser beam L2 reflected by the first polygon mirror 360 propagate are the same optical path. In other words, their optical axes are the same. Note that even when the first pulse laser beam L1 and the second pulse laser beam L2 are reflected by the same reflecting surface, the reflection position of the first pulse laser beam L1 and the reflection position of the second pulse laser beam L2 on the reflecting surface may be different from each other.

[0078] The processor 350 controls the emission timing of the first pulse laser device 120a, the emission timing of the second pulse laser device 120b, and the rotation angle of the first polygon mirror 360 so that the first and second pulse laser beams L1, L2 reflected by the first polygon mirror 360 are reflected in the same first direction. As a result, each pulse laser beam is converted into a pulse combined beam L1, L2 as shown in FIG.12 and propagate along the same optical path. Note that the optical paths of the first and second pulse laser beams L1, L2 need only face the same first direction and at least partially overlap, and their optical axes do not have to completely coincide. However, it is preferable that the optical axis of the first pulse laser beam L1 reflected by the first polygon mirror 360 coincides with the optical axis of the second pulse laser beam L2. The same first direction may have a width of 0.1° or less.

[0079] In this embodiment, the first polygon mirror 360 reflects the first and second pulsed laser beams L1 and L2 in a first direction between the incident first and second pulsed laser beams L1 and L2. The first and second pulsed laser beams L1 and L2 reflected by the first polygon mirror 360 are called pulsed combined beams L 12 propagates between the optical paths of the first and second pulse laser beams L1 and L2 incident on the first polygon mirror 360, and propagates between the first pulse laser device 120a and the second pulse laser device 120b.

[0080] The pulsed combined light L emitted from the first polygon mirror 360 12 is incident on the beam measuring instrument 320 via the mirror 332. The processor 350 calculates the pulsed combined light L 12 The processor 350 controls the beam steering device 310 so that the beam position and pointing of the first pulsed laser beam L1 and the second pulsed laser beam L2 are within a predetermined range. That is, based on the measurement results of the beam measuring device 320, the processor 350 controls the beam steering device 310 so that the optical paths of the first pulsed laser beam L1 and the second pulsed laser beam L2 reflected by the first polygon mirror 360 approach each other. Note that the beam measuring device 320 may measure the pulse energy, power, wavelength, and spectrum of each pulsed beam.

[0081] Pulsed combined light L transmitted through the beam measuring instrument 320 12 enters the pulse stretcher 325, where the temporal pulse width is expanded, and then emerges from the pulse stretcher 325.

[0082] In this way, the laser system 100 emits a pulsed combined light L having a repetition frequency twice that of the first and second pulsed laser lights L1 and L2. 12 is emitted.

[0083] 3.3 Actions and Effects The laser system 100 includes a first pulse laser device 120a that emits a first pulse laser beam L1 at a predetermined period T, a second pulse laser device 120b that emits a second pulse laser beam L2 at the predetermined period T, a first polygon mirror 360 that reflects the first pulse laser beam L1 and the second pulse laser beam L2, and a processor 350 that controls the first pulse laser device 120a, the second pulse laser device 120b, and the first polygon mirror 360 so that the first pulse laser beam L1 and the second pulse laser beam L2 are emitted with an offset of half the predetermined period T and the optical paths of the first pulse laser beam L1 and the second pulse laser beam L2 reflected by the first polygon mirror 360 are directed in the same first direction and at least partially overlap each other.

[0084] The laser system 100 of this embodiment emits pulsed combined light L at a repetition rate twice as high as that of a single pulse laser device. 12 Furthermore, a pulsed combined beam L consisting of the first and second pulsed laser beams L1 and L2 can be emitted. 12 The increase in the beam size and beam divergence of the pulsed combined light L can be suppressed. 12 Therefore, the laser system 100 of this embodiment can emit laser light suitable for exposure. Furthermore, the first and second pulsed laser beams L1 and L2 are reflected by the same polygon mirror at the same angle of incidence to produce a pulsed combined beam L 12 Therefore, the pulsed combined light L 12 The energy and optical quality of each pulse laser beam can be made closer to each other. 12 The optical path can also be easily adjusted.

[0085] In addition, the pulsed combined light L 12However, if the pulsed combined light L does not propagate through the space between the first pulsed laser device 120a and the second pulsed laser device 120b and intersects with the optical path of the laser light emitted from one of the pulsed laser devices 120, an optical path pipe or the like that covers the optical path and creates a predetermined atmosphere around the laser light may intersect, which may complicate the configuration of the laser system 100. However, in this embodiment, the first polygon mirror 360 reflects the first and second pulsed laser beams L1, L2 in a direction between the first and second pulsed laser beams L1, L2 incident on the first polygon mirror 360, and generates the pulsed combined light L 12 propagates between the first pulse laser device 120a and the second pulse laser device 120b. 12 does not intersect with the optical paths of the first and second pulsed laser beams L1 and L2 incident on the first polygon mirror 360, and the configuration of the laser system 100 can be simplified.

[0086] 3.4 Variations Next, a modified example of embodiment 1 will be described. Fig. 9 is a schematic diagram showing a schematic configuration example of a laser system 100 of this modified example. The laser system 100 of this modified example differs from the laser system 100 of the above embodiment in that the number of reflective surfaces of the first polygon mirror 360 is different.

[0087] The number N of reflective surfaces of the first polygon mirror 360 in this modification is 8, which is greater than the number of reflective surfaces of the first polygon mirror 360 in the above embodiment. Therefore, the number of rotations per unit time of the first polygon mirror 360 in this modification can be less than the number of rotations per unit time of the first polygon mirror 360 in the above embodiment. For example, in the above embodiment, the number N of reflective surfaces is 4, and therefore, when the repetition frequency of the first and second pulsed laser beams L1 and L2 is X [Hz], the number of rotations per unit time of the first polygon mirror 360 is X / 4 [rps]. In contrast, in this modification, the number of rotations per unit time of the first polygon mirror 360 can be X / 8 [rps]. Since the number of rotations per unit time of the first polygon mirror 360 can be reduced in this manner, control of the laser system 100 becomes easier. In addition, the amount of change in the angle of the reflecting surface while one pulse is being reflected by the reflecting surface can be reduced, and deviation of the optical paths of the first and second pulsed laser beams L1, L2 reflected by the first polygon mirror 360 can be suppressed.

[0088] Here, it is preferable that the angle of incidence θ of the first pulse laser beam L1 incident on the first polygon mirror 360 from the first pulse laser device 120a and the angle of incidence φ of the second pulse laser beam L2 incident on the first polygon mirror 360 from the second pulse laser device 120b are equal to each other. When the angles of incidence θ and φ are equal and the first polygon mirror 360 includes N reflecting mirrors, the angle of incidence is preferably 360 / 4N°. In this embodiment, since N=8, the angle of incidence is θ=φ=11.25°.

[0089] The number N of reflecting mirrors of the first polygon mirror 360 is not limited to 4 or 8, but may be any natural number equal to or greater than 3.

[0090] 4. Description of the laser system of embodiment 2 A description will be given of a laser system 100 according to embodiment 2. Note that the same components as those described above are given the same reference numerals, and redundant description will be omitted unless otherwise specified.

[0091] 4.1 Configuration 10 is a schematic diagram showing an example of the schematic configuration of a laser system 100 of embodiment 2. The laser system 100 of this embodiment is different from the laser system of embodiment 1 in that it includes two pulsed laser devices 120a and 120b, and generates pulsed combined light L by a single first polygon mirror 360. 12 In contrast, the present invention includes first to fourth pulse laser devices 120a to 120d and generates a third pulse combined beam L using three polygon mirrors, a first polygon mirror 360a, a second polygon mirror 360b, and a third polygon mirror 360c. 1-4 10 and the following figures do not show electrical wiring of the processor 350 in order to avoid complicating the drawings.

[0092] The first polygon mirror 360a has the same configuration as the first polygon mirror 360 of the first embodiment, and similarly to the first embodiment, reflects the first pulsed laser beam L1 and the second pulsed laser beam L2 in a first direction to generate the pulsed combined beam L2 described in the first embodiment. 12 The first pulse combined light L 12 Generate.

[0093] The third and fourth pulse laser devices 120c and 120d have the same configuration as the first and second pulse laser devices 120a and 120b, and emit third and fourth pulse laser beams L3 and L4 at a predetermined period T. The third pulse laser beams L3 and L4 emitted from the third and fourth pulse laser devices 120c and 120d are incident on the second polygon mirror 360b. In this embodiment, the laser system 100 includes a mirror 333 that reflects the fourth pulse laser beam L4, and the fourth pulse laser beam L4 emitted from the fourth pulse laser device 120d is reflected by the mirror 333 and incident on the second polygon mirror 360b.

[0094] In addition, a beam steering device for adjusting the optical path may be provided on at least one of the optical paths from the first and second pulse laser devices 120a and 120b to the first polygon mirror 360a, and on at least one of the optical paths from the third and fourth pulse laser devices 120c and 120d to the second polygon mirror 360b, in the same manner as in the first embodiment.

[0095] The second polygon mirror 360b has the same configuration as the first polygon mirror 360a, and reflects the third pulsed laser beam L3 and the fourth pulsed laser beam L4 in a second direction to generate a second pulsed combined beam L 34 Generate.

[0096] The first pulse combined light L emitted from the first polygon mirror 360a 12 , and the second pulsed combined light L emitted from the second polygon mirror 360b 34 The first pulsed combined light L is incident on the third polygon mirror 360c. 12 is reflected by the mirror 332 and enters the third polygon mirror 360c. In this embodiment, the laser system 100 also generates the second pulsed combined light L 34 The second pulse combined light L emitted from the second polygon mirror 360b is reflected by mirrors 334 and 335. 34 is reflected by mirrors 334 and 335 and enters third polygon mirror 360c.

[0097] The third polygon mirror 360c has the same configuration as the first polygon mirror 360a, and 12 and the second pulse combined light L 34 and is reflected in a third direction to produce the third pulse combined light L 1-4 In this embodiment, the laser system 100 generates the third pulsed combined light L 1-4 The third pulsed combined light L emitted from the third polygon mirror 360c is 1-4 is reflected by the mirror 336 and emitted from the laser system 100. 1-4A beam measuring instrument 320 and a pulse stretcher 325 may be provided on this optical path, similarly to the first embodiment.

[0098] The processor 350 of this embodiment controls the first pulse laser device 120a, the second pulse laser device 120b, the third pulse laser device 120c, the fourth pulse laser device 120d, the first polygon mirror 360a, the second polygon mirror 360b, and the third polygon mirror 360c as described below.

[0099] 4.2 Operation In this embodiment, the first polygon mirror 360a reflects the first and second pulsed laser beams L1 and L2 in a first direction between the incident first and second pulsed laser beams L1 and L2. The first and second pulsed laser beams L1 and L2 reflected by the first polygon mirror 360a are called pulsed combined beams L 12 The pulsed combined light L1 propagates between the optical paths of the first and second pulsed laser beams L1 and L2 incident on the first polygon mirror 360a, and propagates between the first pulsed laser device 120a and the second pulsed laser device 120b. The second polygon mirror 360b reflects the third and fourth pulsed laser beams L3 and L4 in a second direction between the incident third and fourth pulsed laser beams L3 and L4. The pulsed combined light L1, which is the third and fourth pulsed laser beams L3 and L4 reflected by the second polygon mirror 360b, 34 propagates between the optical paths of the third and fourth pulse laser beams L3 and L4 incident on the second polygon mirror 360b, and propagates between the third pulse laser device 120c and the fourth pulse laser device 120d. By arranging in this manner, the number of mirrors can be reduced, the layout can be made more efficient, and the laser system 100 can be made smaller.

[0100] 11 is a timing chart showing the relationship between the emission timings of the first to fourth pulse laser beams L1 to L4. The emission timings of the first and second pulse laser beams L1 and L2 emitted from the first and second pulse laser devices 120a and 120b are the same as those in the first embodiment.

[0101] The emission timings of the third and fourth pulse laser beams L3 and L4 emitted from the third and fourth pulse laser devices 120c and 120d are shifted from the emission timings of the first and second pulse laser beams L1 and L2 by a quarter of a predetermined period T, i.e., T / 4. In this example, the emission timing of the third pulse laser beam L3 is delayed by a quarter of the predetermined period T from the emission timing of the first pulse laser beam L1 and is earlier than the emission timing of the second pulse laser beam L2 by a quarter of the predetermined period T. Furthermore, the emission timing of the fourth pulse laser beam L4 is earlier than the emission timing of the first pulse laser beam L1 by a quarter of the predetermined period T and is later than the emission timing of the second pulse laser beam L2 by a quarter of the predetermined period T.

[0102] The first pulse laser beam L1 emitted from the first pulse laser device 120a and the second pulse laser beam L2 emitted from the second pulse laser device 120b are each reflected by the first polygon mirror 360a to form a first pulse combined beam L 12 As in the first embodiment, the processor 350 controls the emission timings of the first pulse laser device 120a and the second pulse laser device 120b, and the rotation angle of the first polygon mirror 360a.

[0103] The third pulse laser beam L3 emitted from the third pulse laser device 120c and the fourth pulse laser beam L4 emitted from the fourth pulse laser device 120d are each reflected by the second polygon mirror 360b to form a second pulse combined beam L 34 The processor 350 controls the emission timing of the third pulse laser device 120c, the emission timing of the fourth pulse laser device 120d, and the rotation angle of the second polygon mirror 360b so that at least a portion of the optical path of the third pulse laser beam L3 reflected by the second polygon mirror 360b overlaps with at least a portion of the optical path of the fourth pulse laser beam L4 reflected by the second polygon mirror 360b, and so that the third pulse laser beam L3 and the fourth pulse laser beam L4 are reflected in the same second direction.

[0104] FIG. 12 shows the first pulse combined light L 12 and the second pulse combined light L 3410 is a timing chart showing the relationship between the emission timing and the period T / 2 of the first pulsed combined light L. 12 is emitted from the second polygon mirror 360b, and a second pulsed combined light L having a period of T / 2 is emitted from the second polygon mirror 360b. 34 As described above, the emission timings of the third and fourth pulse laser beams L3 and L4 are shifted from the emission timings of the first and second pulse laser beams L1 and L2 by a quarter of the predetermined period T, so that the first pulse combined beam L 12 and the emission timing of the second pulse combined light L 34 The emission timing of the third polygon mirror 360c is shifted by a quarter of a predetermined period T. The number of rotations per unit time of the third polygon mirror 360c is twice that of the first polygon mirror 360a and the second polygon mirror 360b, or, as in a modification of the first embodiment, the third polygon mirror 360c may have twice as many reflective surfaces as the first polygon mirror 360a and the second polygon mirror 360b, and the number of rotations per unit time of the third polygon mirror 360c may be the same as the number of rotations per unit time of the first polygon mirror 360a and the second polygon mirror 360b.

[0105] The first and second pulsed laser beams L1 and L2 emitted from the first and second polygon mirrors 360a and 360b are reflected by the third polygon mirror 360c to form a third pulsed combined beam L 1-4 It is emitted as

[0106] FIG. 13 shows the third pulse combined light L 1-4 As described above, the emission timings of the first to fourth pulsed laser beams L1 to L4 are shifted by ¼ of the predetermined period T. Therefore, the third pulsed combined beam L 1-4 The period of this pulse is 1 / 4 of the predetermined period T. Thus, the third polygon mirror 360c emits the third pulse combined light L 1-4 is emitted.

[0107] Therefore, the processor 350 of this embodiment controls the first to fourth pulse laser devices 120a to 120d and the first to third polygon mirrors 360a to 360c so that the optical paths of the first to fourth pulse laser beams L1 to L4 reflected by the third polygon mirror 360c are directed in the same third direction and at least partially overlap each other.

[0108] The third pulse combined light L 1-4 A beam measuring instrument 320 and a pulse stretcher 325 may be provided on this optical path, similarly to the first embodiment.

[0109] 4.3 Actions and Effects According to the laser system 100 of this embodiment, pulsed laser light can be emitted toward the exposure device 200 at a repetition rate four times higher than that of a single pulsed laser device 120 .

[0110] 4.4 Variations 14 is a schematic diagram showing an example of the schematic configuration of a laser system 100 according to a modification of the second embodiment. In the description of this modification, the same components as those in the laser system 100 described above are denoted by the same reference numerals, and redundant description will be omitted unless otherwise specified. The laser system 100 according to this modification differs from the laser system 100 according to the second embodiment mainly in that the first polygon mirror 360a also serves as the second polygon mirror 360b.

[0111] The first polygon mirror 360a has the same configuration as the first polygon mirror 360 of the first embodiment, and similarly to the first embodiment, reflects the first pulsed laser beam L1 and the second pulsed laser beam L2 in a first direction to generate the pulsed combined beam L2 described in the first embodiment. 12 The first pulse combined light L 12 In this modification, the laser system 100 includes a mirror 337 and a mirror 338 that reflect the first pulse laser beam L1, and the first pulse laser beam L1 emitted from the first pulse laser device 120a is reflected by the mirrors 337 and 338 and enters the first polygon mirror 360a.

[0112] The first polygon mirror 360a also reflects the third pulsed laser beam L3 and the fourth pulsed laser beam L4 in the second direction to form the second pulsed combined beam L2 described in the second embodiment. 34 The second pulse combined light L 34 Generate.

[0113] The third polygon mirror 360c has the same configuration as the first polygon mirror 360a in the first embodiment, and, as in the second embodiment, 12 and the second pulse combined light L 34 and is reflected in a third direction to produce the third pulse combined light L described in the second embodiment. 1-4 The third pulse combined light L 1-4 The number of rotations per unit time of the third polygon mirror 360c is twice that of the first polygon mirror 360a.

[0114] A beam steering device for adjusting the optical path may be provided on at least one of the optical paths from the first and second pulse laser devices 120a and 120b to the first polygon mirror 360a, and on at least one of the optical paths from the third and fourth pulse laser devices 120c and 120d to the first polygon mirror 360a, as in the first embodiment.

[0115] Next, the operation of the modified example will be described.

[0116] The emission timings of the first to fourth pulsed laser beams L1 to L4 are the same as those in the second embodiment. 12 and the second pulse combined light L 34 The relationship between the emission timings is the same as in the second embodiment.

[0117] The first pulse laser beam L1 emitted from the first pulse laser device 120a is reflected by mirrors 337 and 338 and enters the first polygon mirror 360a. At this time, the first and second pulse laser beams L1 and L2 are incident on the same first reflecting surface. However, the rotation angle of the first polygon mirror 360a when the first pulse laser beam L1 is incident is different from the rotation angle of the first polygon mirror 360a when the second pulse laser beam L2 is incident.

[0118] The third pulse laser beams L3 and L4 emitted from the third and fourth pulse laser devices 120c and 120d are incident on the first polygon mirror 360a. At this time, the reflecting surfaces onto which the third and fourth pulse laser beams L3 and L4 are incident are the same second reflecting surface. Here, the second reflecting surface is different from the first reflecting surface. The rotation angle of the first polygon mirror 360a when the third pulse laser beam L3 is incident is different from the rotation angle of the first polygon mirror 360a when the fourth pulse laser beam L4 is incident.

[0119] The first polygon mirror 360a reflects the first pulsed laser beam L1 and the second pulsed laser beam L2 in a first direction to generate a first pulsed combined beam L 12 Generate.

[0120] The first polygon mirror 360a also reflects the third pulsed laser beam L3 and the fourth pulsed laser beam L4 in a second direction to form a second pulsed combined beam L 34 Generate.

[0121] The third polygon mirror 360c reflects the first pulsed combined light L 12 and the second pulse combined light L 34 and is reflected in a third direction to produce the third pulse combined light L 1-4 Generate.

[0122] The processor 350 of this modification controls the first to fourth pulse laser devices 120a to 120d and the first and third polygon mirrors 360a, 360c so that the optical paths of the first to fourth pulse laser beams L1 to L4 reflected by the third polygon mirror 360c are directed in the same third direction and at least partially overlap each other.

[0123] The third pulse combined light L 1-4 A beam measuring instrument 320 and a pulse stretcher 325 may be provided on this optical path, similarly to the second embodiment.

[0124] According to the configuration of this modification, one polygon mirror can be omitted compared to the configuration of the second embodiment, and therefore the configuration of the device can be simplified.

[0125] The above description is intended to be illustrative, not limiting. Accordingly, 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. It will also be apparent to those skilled in the art that the embodiments of the present disclosure can be used in combination. Terms used throughout this specification and claims should be construed as "open-ended" terms unless expressly stated. For example, terms such as "comprise," "have," "comprise," and "equip" should be interpreted as meaning "without excluding the presence of elements other than those listed." The modifier "a" or "an" should be interpreted as meaning "at least one" or "one or more." The term "at least one of A, B, and C" should be interpreted as "A," "B," "C," "A+B," "A+C," "B+C," or "A+B+C," including combinations other than "A," "B," and "C."

Claims

1. a first pulse laser device that emits a first pulse laser beam at a predetermined period; a second pulse laser device that emits second pulse laser light at the predetermined period; a first polygon mirror that reflects the first pulsed laser beam and the second pulsed laser beam; a processor that controls the first pulse laser device, the second pulse laser device, and the first polygon mirror so that the first pulse laser beam and the second pulse laser beam are emitted with a shift of half the predetermined period, and so that optical paths of the first pulse laser beam and the second pulse laser beam reflected by the first polygon mirror are directed in a first direction and at least partially overlap each other; A laser system comprising:

2. 10. The laser system of claim 1, the first polygon mirror includes N reflecting mirrors, each of which has a constant angle between adjacent reflecting mirrors; When the frequency, which is the reciprocal of the predetermined period, is X [Hz], the number of rotations per unit time of the first polygon mirror is X / N [rps].

3. 3. The laser system of claim 2, The angle of incidence of the first pulsed laser beam on the reflecting mirror of the first polygon mirror and the angle of incidence of the second pulsed laser beam on the reflecting mirror of the first polygon mirror are 360 / 4N [°].

4. 3. The laser system of claim 2, The N is 4 or more and 8 or less.

5. 10. The laser system of claim 1, The laser beam source further includes a beam steering device that adjusts at least one of the optical paths of the first pulsed laser beam and the second pulsed laser beam that are incident on the first polygon mirror.

6. 6. The laser system of claim 5, The laser beam source further includes a beam measuring instrument that measures at least one of the beam position and pointing of the first pulsed laser beam and the second pulsed laser beam reflected by the first polygon mirror.

7. 7. The laser system of claim 6, The processor controls the beam steering device based on the measurement result of the beam measuring instrument so that the optical paths of the first pulsed laser beam and the second pulsed laser beam reflected by the first polygon mirror approach each other.

8. 10. The laser system of claim 1, The first pulsed laser beam and the second pulsed laser beam reflected by the first polygon mirror propagate between an optical path of the first pulsed laser beam incident on the first polygon mirror and an optical path of the second pulsed laser beam incident on the first polygon mirror.

9. 10. The laser system of claim 1, The first pulse laser beam and the second pulse laser beam reflected by the first polygon mirror propagate between the first pulse laser device and the second pulse laser device.

10. 10. The laser system of claim 1, The emission direction of the first pulse laser light emitted from the first pulse laser device and the emission direction of the second pulse laser light emitted from the second pulse laser device are opposite to the emission direction of the pulse laser light emitted from the laser system.

11. 10. The laser system of claim 1, The laser beam source further includes a pulse stretcher that stretches the pulse widths of the first pulse laser beam and the second pulse laser beam reflected by the first polygon mirror.

12. 10. The laser system of claim 1, a third pulse laser device that emits a third pulse laser beam at the predetermined period; a fourth pulse laser device that emits a fourth pulse laser beam at the predetermined period; a second polygon mirror that reflects the third pulsed laser beam and the fourth pulsed laser beam; a third polygon mirror that reflects the first pulse laser beam and the second pulse laser beam reflected by the first polygon mirror, and the third pulse laser beam and the fourth pulse laser beam reflected by the second polygon mirror; Further provided with The processor controls the first pulse laser device, the second pulse laser device, the third pulse laser device, the fourth pulse laser device, the first polygon mirror, the second polygon mirror, and the third polygon mirror so that the third pulse laser beam and the fourth pulse laser beam are emitted with a shift of half the predetermined period and are emitted with a shift of a quarter of the predetermined period from the first pulse laser beam and the second pulse laser beam, and so that the optical paths of the third pulse laser beam and the fourth pulse laser beam reflected by the second polygon mirror face in a second direction and at least partially overlap with each other, and so that the optical paths of the first pulse laser beam, the second pulse laser beam, the third pulse laser beam, and the fourth pulse laser beam reflected by the third polygon mirror face in a third direction and at least partially overlap with each other.

13. 13. The laser system of claim 12, The first polygon mirror also serves as the second polygon mirror.

14. a first pulse laser device that emits a first pulse laser beam at a predetermined period; a second pulse laser device that emits second pulse laser light at the predetermined period; a first polygon mirror that reflects the first pulsed laser beam and the second pulsed laser beam; a processor that controls the first pulse laser device, the second pulse laser device, and the first polygon mirror so that the first pulse laser beam and the second pulse laser beam are emitted with a shift of half the predetermined period, and so that optical paths of the first pulse laser beam and the second pulse laser beam reflected by the first polygon mirror are directed in a first direction and at least partially overlap each other; outputting the first pulsed laser beam and the second pulsed laser beam generated by a laser system comprising: In order to manufacture an electronic device, a photosensitive substrate is exposed to the first pulsed laser beam and the second pulsed laser beam in the exposure apparatus. A method for manufacturing an electronic device, comprising:

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