Methods for manufacturing laser systems and electronic devices

Abstract

A laser system according to the present invention is provided with: a pump laser device which outputs a pump laser light beam having a first wavelength; a signal laser device which outputs a signal laser light beam having a second wavelength that is longer than the first wavelength; and an amplification system which comprises a plurality of optical parametric crystals each outputting an amplified light beam having the second wavelength. The amplification system is provided with a first beam diameter adjusting optical system which is arranged such that: the beam waist position of a first amplified light beam which is outputted from a first optical parametric crystal and incident on a second optical parametric crystal, while having the second wavelength, and the beam waist position of a pump laser light beam which is incident on the second optical parametric crystal coincide with each other; and the first amplified light beam and the pump laser light beam are coaxially incident on the second optical parametric crystal. With respect to this first beam diameter adjusting optical system, the ratio of the beam waist diameter of the pump laser light beam to the beam waist diameter of the first amplified light beam in the second optical parametric crystal is higher than the ratio of the beam waist diameter of the pump laser light beam to the beam waist diameter of the signal laser light beam in the first optical parametric crystal.

Description

[Technical Field]

[0001] This disclosure relates to a method for manufacturing laser systems and electronic devices. [Background technology]

[0002] In recent years, semiconductor lithography equipment has been required to improve resolution as semiconductor integrated circuits become smaller and more integrated. Therefore, efforts are being made to shorten the wavelength of light emitted from lithography light sources. For example, gas laser equipment used for lithography includes KrF excimer laser equipment that outputs laser light with a wavelength of approximately 248 nm, and ArF excimer laser equipment that outputs laser light with a wavelength of approximately 193 nm.

[0003] The spectral linewidth of the spontaneously emitted light from KrF and ArF excimer laser systems is broad, ranging from 350 to 400 pm. Therefore, when 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 a gas laser system until chromatic aberration is negligible. For this reason, gas laser systems may be equipped with a Line Narrowing Module (LNM) containing narrowing elements (such as etalons or gratings) within the laser resonator to narrow the spectral linewidth. In the following, a gas laser system with a narrowed spectral linewidth will be referred to as a narrow-band gas laser system. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] U.S. Patent No. 6208458 [Patent Document 2] Japanese Patent Publication No. 2001-27771 [Patent Document 3] Summary of Japanese Patent Publication No. 2010-66381

[0005] A laser system relating to one aspect of this disclosure comprises a pump laser device that outputs pump laser light of a first wavelength, a signal laser device that outputs signal laser light of a second wavelength longer than the first wavelength, and an amplification system including a plurality of optical parametric crystals that transmit the pump laser light and the signal laser light to output amplified light of the second wavelength, wherein the plurality of optical parametric crystals include a first optical parametric crystal and a second optical parametric crystal arranged in series with the first optical parametric crystal, and the amplification system outputs a first optical parametric crystal of the second wavelength that is output from the first optical parametric crystal and incident on the second optical parametric crystal. The first beam diameter adjustment optical system is provided such that the beam waist positions of the amplified light and the pump laser light incident on the second parametric optical crystal coincide with each other, the first amplified light and the pump laser light are arranged to be incident on the second parametric optical crystal coaxially, and the ratio of the beam waist diameter of the pump laser light in the second parametric optical crystal to the beam waist diameter of the first amplified light in the second parametric optical crystal is set to be greater than the ratio of the beam waist diameter of the pump laser light in the first parametric optical crystal to the beam waist diameter of the signal laser light in the first parametric optical crystal.

[0006] A method for manufacturing an electronic device relating to another aspect of the present disclosure comprises a pump laser device that outputs pump laser light of a first wavelength, a signal laser device that outputs signal laser light of a second wavelength longer than the first wavelength, and an amplification system that includes a plurality of optical parametric crystals that transmit the pump laser light and the signal laser light to output amplified light of a second wavelength, wherein the plurality of optical parametric crystals include a first optical parametric crystal and a second optical parametric crystal arranged in series with the first optical parametric crystal, and the amplification system is such that the beam waist positions of the first amplified light of a second wavelength output from the first optical parametric crystal and incident on the second optical parametric crystal and the pump laser light incident on the second optical parametric crystal coincide with each other, and The laser system includes a first beam diameter adjustment optical system in which amplified light and pump laser light are arranged to be incident coaxially on a second optical parametric crystal, and the ratio of the beam waist diameter of the pump laser light in the second optical parametric crystal to the beam waist diameter of the first amplified light in the second optical parametric crystal is set to be greater than the ratio of the beam waist diameter of the pump laser light in the first optical parametric crystal to the beam waist diameter of the signal laser light in the first optical parametric crystal; the second wavelength laser light is wavelength-converted to generate ultraviolet laser light; the ultraviolet laser light is output to an exposure apparatus; and the ultraviolet laser light is exposed to a photosensitive substrate in the exposure apparatus in order to manufacture an electronic device. [Brief explanation of the drawing]

[0007] Some embodiments of this disclosure are described below, merely as examples, with reference to the accompanying drawings. [Figure 1] Figure 1 schematically shows the configuration of an exemplary solid-state laser system. [Figure 2] Figure 2 schematically shows the configuration of the amplification system in a solid-state laser system. [Figure 3] Figure 3 schematically shows an example of a beam diameter adjustment optical system configuration. [Figure 4]FIG. 4 is an explanatory diagram schematically showing the propagation of laser light inside each optical parametric crystal and near the input / output portions in the amplification system applied to the laser system according to the comparative example. [Figure 5] FIG. 5 is an explanatory diagram schematically showing the propagation of laser light inside each optical parametric crystal and near the input / output portions in the amplification system applied to the laser system according to Embodiment 1. [Figure 6] FIG. 6 schematically shows the configuration of the amplification system applied to the laser system according to Embodiment 2. [Figure 7] FIG. 7 schematically shows Modification 1 of the beam diameter adjustment optical system. [Figure 8] FIG. 8 schematically shows Modification 2 of the beam diameter adjustment optical system. [Figure 9] FIG. 9 schematically shows the configuration of the exposure apparatus. Embodiment

[0008] -Contents- 1. Description of Solid Laser System 1.1 Configuration 1.2 Operation 1.3 Description of Amplification System 1.3.1 Configuration 1.3.2 Operation 2. Problems 3. Embodiment 1 3.1 Configuration 3.2 Operation 3.3 Basis of Conditions for Beam Waist Diameter Ratio 3.3. Subheading 1 Calculation of Divergence Angle Ratio 3.3.2 Calculation of Pump Laser Light Utilization Efficiency 3.4 Function and Effect 4. Embodiment 2 <000009,6>4.1 Configuration 4.2 Operation 4.3 Function and Effect 5. Modification 1 of Beam Diameter Adjustment Optical System 5.1 Configuration 5.2 Operation 5.3 Function and Effect 5.4 Control Example 6. Modification 2 of Beam Diameter Adjustment Optical System 7. Laser systems using excimer amplifiers 8. Methods for manufacturing electronic devices 9. Other The embodiments of this disclosure will be described in detail below with reference to the drawings. The embodiments described below are examples of the disclosure and are not intended to limit the scope of this disclosure. Furthermore, not all configurations and operations described in each embodiment are necessarily essential to the configurations and operations of this disclosure. The same reference numerals are used for identical components, and redundant descriptions are omitted.

[0009] 1. Description of Solid-State Laser Systems 1.1 Configuration Figure 1 schematically shows the configuration of an exemplary solid-state laser system 10.

[0010] The solid-state laser system 10 includes a laser system 100 comprising a signal laser device 20, an amplification system 30, and a pump laser device 40, a wavelength conversion system 50, and a solid-state laser control unit 60. The solid-state laser system 10 outputs pulsed laser light with a wavelength of approximately 1553 nm and pulsed laser light with a wavelength of approximately 257.6 nm from the laser system 100, and outputs pulsed laser light with a wavelength of approximately 193.4 nm by inputting both pulsed laser beams into the wavelength conversion system 50 and performing wavelength conversion.

[0011] The signal laser device 20 includes a semiconductor laser 21 and a solid-state amplifier 22. The semiconductor laser 21 oscillates in a single longitudinal mode (CW) with a wavelength of approximately 1553 nm.

[0012] The solid-state amplifier 22 includes a semiconductor optical amplifier (SOA) that amplifies the CW-oscillating laser light output from the semiconductor laser 21.

[0013] The pump laser device 40 includes a semiconductor laser 42, a solid-state amplifier 43, nonlinear optical crystals LBO crystal 45 and CLBO crystal 46, and a dichroic mirror DM1. "LBO" is represented by the chemical formula LiB3O5. "CLBO" is represented by the chemical formula CsLiB6O 10 It is represented as follows.

[0014] The semiconductor laser 42 oscillates in CW mode in a single longitudinal mode at a wavelength of approximately 1030 nm. The solid-state amplifier 43 is an amplifier that includes SOA, a Yb fiber amplifier, and a Yb:YAG crystal.

[0015] The combination of two nonlinear optical crystals, LBO crystal 45 and CLBO crystal 46, converts wavelengths from approximately 1030 nm to fourth harmonic light (wavelength approximately 257.6 nm).

[0016] The dichroic mirror DM1 is positioned in the optical path between the LBO crystal 45 and the CLBO crystal 46, and transmits pulsed laser light with a wavelength of approximately 515 nm with high transparency and reflects pulsed laser light with a wavelength of approximately 1030 nm with high transparency. The pulsed laser light with a wavelength of approximately 1030 nm, which is highly reflected by the dichroic mirror DM1, is incident on the amplification system 30 as pump laser light.

[0017] The amplification system 30 includes an optical parametric amplifier (OPA). The OPA is an amplifier that includes, for example, a PPLN crystal (periodically poled lithium niobate crystal) or a PPKTP crystal (periodically poled KTP crystal). The OPA pulses the signal laser light by inputting the pump laser light and the signal laser light.

[0018] The wavelength conversion system 50 includes a dichroic mirror DM2, two CLBO crystals 52 and 53, and two rotating stages 54 and 55 for changing the incident angles of CLBO crystals 52 and 53, respectively. CLBO crystals 52 and 53 are placed on rotating stages 54 and 55, each containing a piezoelectric element (not shown), and are configured to allow rapid changes in the incident angle of each crystal.

[0019] The dichroic mirror DM2 is configured to highly reflect pulsed laser light with a wavelength of approximately 1533 nm output from the amplification system 30 and highly transmit pulsed laser light with a wavelength of approximately 257.6 nm output from the CLBO crystal 46 of the pump laser device 40, and is positioned so that both pulsed laser beams are incident coaxially on the CLBO crystal 52.

[0020] CLBO crystals 52 and 53 are arranged in series, and pulsed laser light with a wavelength of approximately 193.4 nm is output by two sum frequency generation processes.

[0021] The solid-state laser control unit 60 is connected to the signal laser device 20, the pump laser device 40, and the wavelength conversion system 50, and includes a processor (not shown). The processor is a processing unit comprising a CPU (Central Processing Unit) (not shown) and memory. The processor may also include a GPU (Graphics Processing Unit). The processor is specially configured or programmed to perform the various processes included in this disclosure.

[0022] 1.2 Operation The solid-state laser control unit 60 controls the current value of the semiconductor laser 42 of the pump laser device 40 to cause continuous wave oscillation and output continuous wave laser light with a wavelength of approximately 1030 nm. Furthermore, the solid-state laser control unit 60 pulses the continuous wave laser light using the SOA of the solid-state amplifier 43 and amplifies the pulses using the Yb fiber amplifier and amplifiers containing Yb:YAG crystals of the solid-state amplifier 43.

[0023] The LBO crystal 45 converts pulsed laser light with a wavelength of approximately 1030 nm into second harmonic light with a wavelength of approximately 515 nm. The second harmonic light with a wavelength of approximately 515 nm is highly transmitted through the dichroic mirror DM1 and further converted into pulsed laser light, which is ultraviolet light with a wavelength of approximately 257.6 nm, by the CLBO crystal 46.

[0024] Here, the dichroic mirror DM1 highly reflects pulsed laser light with a wavelength of approximately 1030 nm that was not wavelength-converted by the LBO crystal 45, and directs it into the OPA as the pump laser light of the amplification system 30.

[0025] Furthermore, the solid-state laser control unit 60 controls the current value of the semiconductor laser 21 of the signal laser device 20 to output CW laser light with a wavelength of approximately 1553 nm. In addition, the solid-state laser control unit 60 amplifies the signal laser light using the solid-state amplifier 22, causing the signal laser device 20 to output CW laser light with a wavelength of approximately 1553 nm.

[0026] The OPA of the amplification system 30 receives pulsed laser light with a wavelength of approximately 1030 nm reflected by the dichroic mirror DM1 as the pump laser light, and also receives CW laser light with a wavelength of approximately 1553 nm output from the signal laser device 20 as the signal laser light, thereby outputting amplified pulsed laser light with a wavelength of approximately 1553 nm.

[0027] The pulsed laser light with a wavelength of approximately 1553 nm output from the amplification system 30 and the pulsed laser light with a wavelength of approximately 257.6 nm output from the pump laser device 40 are input to the wavelength conversion system 50. The pulsed laser light with a wavelength of approximately 1553 nm reflected by the dichroic mirror DM2 and the pulsed laser light with a wavelength of approximately 257.6 nm transmitted through the dichroic mirror DM2 are incident coaxially on the CLBO crystal 52. Then, the CLBO crystal 52 generates a sum frequency and converts the wavelength to approximately 220.9 nm, and then, in the CLBO crystal 53, the sum frequency is converted with the pulsed laser light with a wavelength of approximately 1553 nm to output a pulsed laser light with a wavelength of approximately 193.4 nm.

[0028] The incidence angles to the CLBO crystals 52 and 53 are adjusted by the solid-state laser control unit 60, and the wavelength conversion efficiency may be compensated.

[0029] 1.3 Description of the Amplification System 1.3.1 Configuration Figure 2 schematically shows the configuration of the amplification system 30. The amplification system 30 includes multiple PPLN crystals 301, 302, beam diameter adjustment optical systems 311-314, dichroic mirrors DM3-DM6, dampers 330, 332, beam splitter BS1, and optical path forming mirrors MR1-MR3.

[0030] The beam diameter adjustment optical systems 311 and 312 are configured so that the beam waist diameters in the PPLN crystal 301 are approximately the same for both the signal laser light and the pump laser light incident on the crystal. The beam diameter adjustment optical system 311 is positioned on the optical path of the signal laser light, and the beam diameter adjustment optical system 312 is positioned on the optical path of the pump laser light.

[0031] The beam diameter adjustment optical systems 313 and 314 are configured so that the beam waist diameters in the PPLN crystal 302 are approximately the same for both the signal laser light and the pump laser light incident on the PPLN crystal 302. The beam diameter adjustment optical system 313 is positioned on the optical path of the signal laser light between the PPLN crystal 301 and the PPLN crystal 302, and the beam diameter adjustment optical system 314 is positioned on the optical path of the pump laser light.

[0032] Each of the beam diameter adjustment optical systems 311 to 314 may be configured, for example, to maintain the distance between opposing lens pairs (see Figure 3). The beam diameter adjustment optical systems 311 to 314 can adjust the beam waist position and beam waist diameter of the signal laser light and the pump laser light, respectively.

[0033] The beam splitter BS1 is positioned on the optical path of the pump laser beam so as to split the pump laser beam from the pump laser device 40 and direct it into the beam diameter adjustment optical systems 312 and 314, respectively. The mirror MR1 is positioned to reflect the pump laser beam reflected by the beam splitter BS1 and guide it to the beam diameter adjustment optical system 314.

[0034] The dichroic mirrors DM3 and DM5 are designed to combine the signal laser beam and the pump laser beam and direct both laser beams coaxially onto the PPLN crystals 301 and 302. For example, the dichroic mirrors DM3 and DM5 highly reflect light with a wavelength of approximately 1553 nm and highly transmit light with a wavelength of approximately 1030 nm. The dichroic mirror DM3 is positioned in the optical path between the beam diameter adjustment optical systems 311 and 312 and the PPLN crystal 301. The dichroic mirror DM5 is positioned in the optical path between the beam diameter adjustment optical systems 313 and 314 and the PPLN crystal 302. Mirror MR2 is positioned to direct the signal laser beam emitted from the beam diameter adjustment optical system 311 onto the dichroic mirror DM3.

[0035] The dichroic mirrors DM4 and DM6 are used to separate the pump laser light and idler light from the output light of the PPLN crystals 301 and 302. For example, the dichroic mirrors DM4 and DM6 highly reflect signal laser light with a wavelength of approximately 1553 nm and highly transmit pump laser light with a wavelength of approximately 1030 nm and idler light with a wavelength of approximately 3070 nm.

[0036] Dampers 330 and 332 absorb the pump laser light and idler light separated by dichroic mirrors DM4 and DM6. Multiple mirrors MR1 ​​to MR3 are arranged to form the optical path of the OPA.

[0037] Figure 3 shows an example configuration of the beam diameter adjustment optical system 311. The beam diameter adjustment optical system 311 includes lenses 321 and 322. Lenses 321 and 322 are each held by lens holders 323 and 324, and are arranged facing each other on the base plate 326. The other beam diameter adjustment optical systems 312 to 314 may have a similar configuration.

[0038] 1.3.2 Operation Figure 4 schematically shows the propagation of signal laser light, pump laser light, and amplified light within the PPLN crystals 301 and 302 and near the input / output sections in a cross-section including the optical axis of the signal laser light of the amplification system 30 applied to the laser system 100 according to the comparative example. The comparative examples in this disclosure are forms that the applicant recognizes as being known only to the applicant, and are not prior art that the applicant acknowledges. The cross-sectional profiles SP1 and SP2, associated with Figure 4, left F4A and right F4B respectively, schematically show the cross-sectional intensity distribution at the beam waist position within the crystal for the signal laser light, pump laser light, and amplified light, respectively. In each cross-sectional profile SP1 and SP2, the transverse direction represents the radial direction of the beam waist, and the vertical direction represents the normalized intensity.

[0039] In Figure 4, the signal laser light, pump laser light, and amplified light for each PPLN crystal 301 and 302 are labeled "Signal input," "Pump," and "Signal output," respectively.

[0040] The signal laser beam and pump laser beam, incident on the amplification system 30, are incident on the PPLN crystal 301 via beam diameter adjustment optics 311 and 312, respectively. At this time, the beam waist positions of the signal laser beam and pump laser beam incident on the PPLN crystal 301 coincide with each other, and the beam waist diameters inside the PPLN crystal 301 of the coaxially incident laser beams are set to be approximately the same for the pump laser beam and the signal laser beam (see Figure 4, left, F4A). When the signal laser beam and pump laser beam are incident on the PPLN crystal 301, optical parametric amplification occurs in the PPLN crystal 301, generating amplified light with the same wavelength as the signal laser beam (approximately 1553 nm) and idler light with a wavelength corresponding to the difference frequency between the signal laser beam and the pump laser beam (approximately 3070 nm).

[0041] The pump laser light and idler light emitted from the PPLN crystal 301 are absorbed by the damper 330 via the dichroic mirror DM4.

[0042] Light with a wavelength of approximately 1553 nm, including amplified light and signal laser light, output from the PPLN crystal 301, is incident on the PPLN crystal 302 via the dichroic mirror DM4, the beam diameter adjustment optical system 313, and the dichroic mirror DM5. The laser light with a wavelength of approximately 1553 nm output from the PPLN crystal 301 becomes the signal laser light input to the PPLN crystal 302.

[0043] Furthermore, the pump laser light, split by the beam splitter BS1, is incident on the PPLN crystal 302 via mirror MR1, beam diameter adjustment optical system 314, and dichroic mirror DM5. At this time, the beam waist diameter inside the PPLN crystal 302 is set to be approximately the same for the pump laser light and the signal laser light (see Figure 4, right, F4B). Optical parametric amplification occurs in the PPLN crystal 302, generating amplified light with the same wavelength as the signal laser light (approximately 1553 nm) and idler light with a wavelength corresponding to the difference frequency between the signal laser light and the pump laser light (approximately 3070 nm).

[0044] The pump laser light and idler light output from the PPLN crystal 302 are absorbed by the damper 332 via the dichroic mirror DM6. The amplified light and signal laser light output from the PPLN crystal 302 are used for sum frequency generation in the CLBO crystal 52 of the wavelength conversion system 50 (see Figure 1).

[0045] 1.3.3 Action and Effects The beam waist diameters within PPLN crystals 301 and 302 are adjusted to be approximately the same for the pump laser beam and the signal laser beam. This is done to set beam waists of the same diameter near the crystal center in order to have a wide region where efficient phase matching can be achieved at the beam waist position where the beam can be considered a plane wave. As a result, mode matching between the signal laser beam and the pump laser beam is improved, and a strongly amplified light is obtained.

[0046] 2. Challenges The output light from PPLN crystals 301 and 302 includes not only amplified light and idler light, but also transmitted light from the input signal laser (transmitted signal laser light). As mentioned above, in order to efficiently generate amplified light, the amplification system 30 of the comparative example is set so that the beam waist diameter inside the PPLN crystals 301 and 302 is approximately the same for the pump laser light and the signal laser light.

[0047] The power density of the amplified light is proportional to the product of the power densities of the input signal laser light and the pump laser light. Therefore, the amplified light has a smaller beam diameter at the beam waist and a larger divergence angle than the input signal laser light. On the other hand, the input signal laser light is also emitted directly from the PPLN crystals 301 and 302, so light with two different divergence angles at the same wavelength is output from each of the PPLN crystals 301 and 302.

[0048] The input signal laser beam and the amplified beam, having the same wavelength but different divergence angles, propagate differently. In other words, two beams with the same wavelength and similar power but different divergence angles propagate coaxially. This can become problematic as the power difference between the input signal laser beam and the amplified beam decreases. Specifically, the following issues may arise:

[0049] [Problem] In the optical system after an OPA, two beams of the same wavelength with different focusing positions coexist, potentially requiring a complex optical system for applications that demand precise focusing and imaging. In particular, in applications such as multi-stage amplification, where the amplification approaches saturation as the stage progresses, adjusting the beam propagation in the later stages becomes difficult.

[0050] 3. Embodiment 1 3.1 Configuration The configuration of the laser system 100 according to Embodiment 1 may be the same as the configuration shown in Figures 1 to 3. Figure 5 schematically shows the propagation of signal laser light, pump laser light, and amplified light inside the PPLN crystals 301 and 302 and near the input and output sections of the amplification system 30 applied to the laser system 100 according to Embodiment 1. The cross-sectional profiles SP1 and SP2B attached to the left figure F5A and the right figure F5B of Figure 5 respectively schematically show the cross-sectional intensity distribution at the beam waist position in the crystal for the signal laser light, pump laser light, and amplified light. In each cross-sectional profile SP1 and SP2B, the lateral direction indicates the radial direction of the beam waist, and the vertical direction indicates the normalized intensity.

[0051] In the laser system 100 according to Embodiment 1, the beam propagation shown in Figure 5 is achieved instead of the beam propagation described in Figure 3. That is, as shown in Figure 5, left F5A, the beam diameter adjustment optical systems 311 and 312 are set so that the pump laser light and the signal laser light take the beam waist at the center of the PPLN crystal 301. At this time, the beam waist diameters of the pump laser light and the signal laser light are set to be approximately the same. This point is the same as in the comparative example described in Figure 4, left F4A.

[0052] In other words, the beam waist positions of the pump laser beam and the signal laser beam incident on the PPLN crystal 301 are aligned, and the beam diameter adjustment optical systems 311 and 312 are set so that the beam waist diameters of both beams are the same at the center of the PPLN crystal 301. Note that the term "center" in relation to the crystal does not refer to the exact center point, but includes the area near the center that can be considered approximately the center. The term "aligned" does not refer to the case where they are exactly the same, but includes the concept of being aligned within an acceptable range that can be considered substantially the same. Furthermore, the term "same diameter" for beam waist diameters does not refer to the case where they are exactly the same (equal) in diameter, but includes the concept of being the same diameter within an acceptable range that can be considered substantially the same.

[0053] Furthermore, in the laser system 100 according to Embodiment 1, as shown in Figure F5B on the right of Figure 5, the beam diameter adjustment optical systems 313 and 314 are adjusted so that the pump laser light and the signal laser light take the beam waist at the center of the PPLN crystal 302.

[0054] In this process, the beam waist positions of the pump laser light incident on the PPLN crystal 302 and the signal laser light (amplified light from the PPLN crystal 301) are made to coincide at the center of the PPLN crystal 302, and the ratio of the beam waist diameter of the pump laser light to the beam waist diameter of the signal laser light within the PPLN crystal 302 is made to be greater than the ratio of the beam waist diameter of the pump laser light to the beam waist diameter of the signal laser light within the PPLN crystal 301 (1x). Therefore, the beam diameter adjustment optical systems 313 and 314 are set so that the beam waist diameter of the pump laser light within the PPLN crystal 302 is in the range of 1.5 to 2.6 times the beam waist diameter of the signal laser light. The conditions for the ratio of the beam waist diameter of the pump laser light to the beam waist diameter of the signal laser light specified here are based on the conditions that the divergence angle ratio between the transmitted signal laser light and the amplified light is 0.8 to 1.2 times, and the utilization efficiency of the pump laser light is 25% or more. The basis for the preferred range regarding the beam waist diameter ratio will be described later.

[0055] 3.2 Operation In the amplification system 30, in which PPLN crystals 301 and 302 are arranged in series, optical parametric amplification occurs in the first stage (initial stage) PPLN crystal 301, generating amplified light with the same wavelength as the signal laser light. To ensure a wide region where the beam can be treated as a plane wave and phase matching can be efficiently achieved, the beam diameter adjustment optics 311 and 312 are adjusted so that the beam waist is the same diameter near the crystal center of PPLN crystal 301. At this time, amplified light with a larger divergence angle than the signal laser light is generated in PPLN crystal 301, but the signal laser light transmitted through PPLN crystal 301 is often much weaker in power than the amplified light. This is because the first stage of the amplification stage in multi-stage amplification is often set to prioritize amplification gain.

[0056] The beam diameter adjustment optical system 313 is set for the propagation of amplified light output from the PPLN crystal 301. Therefore, the transmitted signal laser light, which has a different divergence angle from the amplified light, is attenuated by vignetting and diffusion. As a result, the amount of transmitted signal laser light incident on the second stage PPLN crystal 302 becomes negligibly small.

[0057] On the other hand, the amplified light output by the PPLN crystal 301 is incident as the signal laser light of the PPLN crystal 302 and is further amplified by optical parametric amplification. At this time, amplified light with the same wavelength as the input signal laser light of the PPLN crystal 302 is generated, but since the pump laser light within the PPLN crystal 302 is adjusted to have a beam waist diameter 1.5 to 2.6 times that of the signal laser light, the amplified light output from the PPLN crystal 302 has a divergence angle of about the same magnitude as the signal laser light transmitted through the PPLN crystal 302. Here, the power of the signal laser light transmitted through the PPLN crystal 302 is a value that cannot be ignored with respect to the corresponding amplified light. This is because the multiple stages of amplification in multi-stage amplification are often set using the saturation region of the amplification curve. However, according to the configuration of Embodiment 1, the transmitted signal laser light of the PPLN crystal 302 and the amplified light of the PPLN crystal 302 can be made to have a divergence angle of about the same magnitude.

[0058] In other words, the ratio of the beam waist diameter of the pump laser beam to the beam waist diameter of the signal laser beam in the first-stage PPLN crystal 301 is approximately 1, while the ratio of the beam waist diameter of the pump laser beam to the beam waist diameter of the signal laser beam (amplified light from PPLN crystal 301) in the second-stage PPLN crystal 302 is set to a larger range of 1.5 to 2.6 times. As a result, the transmitted signal laser beam (amplified light from PPLN crystal 301) output from PPLN crystal 302 and the amplified light from PPLN crystal 302 propagate at similar divergence angles. Other operations are the same as those of the solid-state laser system 10 in Figure 1.

[0059] PPLN crystal 301 is an example of the "first optical parametric crystal" in this disclosure, and PPLN crystal 302 is an example of the "second optical parametric crystal" in this disclosure. Beam diameter adjustment optical system 313 and beam diameter adjustment optical system 314 are examples of the "first beam diameter adjustment optical system" in this disclosure. Beam diameter adjustment optical system 311 and beam diameter adjustment optical system 312 are examples of the "second beam diameter adjustment optical system" in this disclosure. Beam diameter adjustment optical system 313 is an example of the "third beam diameter adjustment optical system" in this disclosure, and beam diameter adjustment optical system 314 is an example of the "fourth beam diameter adjustment optical system" in this disclosure. Beam diameter adjustment optical system 311 is an example of the "fifth beam diameter adjustment optical system" in this disclosure, and beam diameter adjustment optical system 312 is an example of the "sixth beam diameter adjustment optical system" in this disclosure.

[0060] A wavelength of about 1030 nm is an example of the "first wavelength" in the present disclosure, and a wavelength of about 1553 nm is an example of the "second wavelength" in the present disclosure. The semiconductor laser 42 is an example of the "first semiconductor laser" in the present disclosure, and the CW laser light output from the semiconductor laser 42 is an example of the "first CW laser light" in the present disclosure. The semiconductor laser 21 is an example of the "second semiconductor laser" in the present disclosure, and the CW laser light output from the semiconductor laser 21 is an example of the "second CW laser light" in the present disclosure. The solid-state amplifier 43 is an example of the "first solid-state amplifier" in the present disclosure, and the solid-state amplifier 22 is an example of the "second solid-state amplifier" in the present disclosure. The amplified light output from the PPLN crystal 301 is an example of the "first amplified light" in the present disclosure, and the amplified light output from the PPLN crystal 302 is an example of the "second amplified light" in the present disclosure. Each of the solid-state laser system 10 and the laser system 100 is an example of the "laser system" in the present disclosure.

[0061] 3.3 Basis for the condition of the beam waist diameter ratio 3.3.1 Calculation of the divergence angle ratio Here, the basis for the condition that it is preferable that the beam waist diameter of the pump laser light is 1.5 to 2.6 times the beam waist diameter of the signal laser light will be described.

[0062] Let the beam intensities of the input signal laser light, the pump laser light, and the amplified light of the PPLN crystal be I s , I p , I a respectively, and assume that each light is a Gaussian beam with a 1 / e 2 radius w s , w p , w a . Assuming that the beam intensity I a of the amplified light is proportional to the product of the beam intensity I s of the input signal laser light and the beam intensity I p of the pump laser light, the beam intensity distribution I a (x, y) of the amplified light is expressed as the following equation (1).

[0063]

number

[0064]

number

[0065]

number

[0066]

number

[0067] 3.3.2 Calculation of Pump Laser Light Utilization Efficiency The upper limit of the preferred beam waist diameter ratio is determined from the viewpoint of pump laser light utilization efficiency. Here, the pump laser light utilization efficiency E is defined as shown in equation (5).

[0068]

number

[0069]

number

number

[0070]

number

[0071]

number

[0072] 3.4 Action and Effects According to Embodiment 1, the divergence angles of the signal laser light and the amplified light after passing through the PPLN crystal 302 are approximately the same, making it easy to adjust the beam diameter in the subsequent optical system. On the other hand, with the PPLN crystal 301, the mode matching between the signal laser light and the pump laser light is improved, resulting in a strong amplified light. This makes efficient multi-stage amplification easier.

[0073] 4. Embodiment 2 4.1 Configuration The amplification system 30 described using Figure 2 is configured for two-stage optical parametric amplification using two PPLN crystals 301 and 302, but it may also be configured for three or more stages of optical parametric amplification. When performing three or more stages of optical parametric amplification, only the first stage (1st stage) PPLN crystal 301 has beam waist diameters of the pump laser light and the signal laser light that are approximately the same, while all PPLN crystals from the second stage PPLN crystal 302 onward have a beam waist diameter of the pump laser light that is 1.5 to 2.6 times that of the signal laser light.

[0074] In a series-arranged configuration of multiple PPLN crystals, the beam waist diameters of both the signal laser and pump laser beams may be increased relative to the later PPLN crystals. This is particularly useful when using larger PPLN crystals in the later stages of the system.

[0075] In the later stages of multi-stage amplification, the power of the signal laser beam and the amplified beam increases, and the energy density at the beam waist tends to become high. Therefore, to prevent the energy density from exceeding the damage threshold of the PPLN crystal, it is preferable to select a PPLN crystal with a large cross-sectional area in the later stages and to increase both the beam waist diameter of the signal laser beam and the pump laser beam. In other words, the PPLN crystal cross-sectional area in the plane perpendicular to the optical axes of the signal laser beam and the pump laser beam at the beam waist should be larger for the PPLN crystal placed in the later stages than for the PPLN crystal placed in the earlier stages. Accordingly, both the beam waist diameter of the signal laser beam and the pump laser beam within the PPLN crystal should be increased in the later stages. However, the beam waist diameter of the pump laser beam within each PPLN crystal should be 1.5 to 2.6 times the beam waist diameter of the signal laser beam.

[0076] Figure 6 schematically shows the configuration of the amplification system 32 applied to the laser system 100 according to Embodiment 2. The amplification system 32 shown in Figure 6 may be applied instead of the amplification system 30 described in Figure 2. The differences between the amplification system 32 shown in Figure 6 and the amplification system 30 shown in Figure 2 will be explained.

[0077] The amplification system 32 is configured to perform three stages of optical parametric amplification, with three PPLN crystals 301, 302, and 303 arranged in series. Specifically, the amplification system 32 adds a beam diameter adjustment optical system 315, a dichroic mirror DM7, a PPLN crystal 303, a dichroic mirror DM8, and a damper 334 after the PPLN crystal 302 in Figure 2. Furthermore, the amplification system 32 includes a beam splitter BS2 instead of the mirror MR1 in Figure 2, and also includes a mirror MR4 and a beam diameter adjustment optical system 316 to guide the pump laser light split by the beam splitter BS2 to the PPLN crystal 303.

[0078] 4.2 Operation The operation of the amplification stage up to the second stage is the same as in Embodiment 1. The amplified light and transmitted signal laser light with a wavelength of approximately 1553 nm output from the PPLN crystal 302 become the signal laser light for the third stage PPLN crystal 303. The amplified light from the PPLN crystal 302 and the transmitted signal laser light that has passed through the PPLN crystal 302 are reflected by the dichroic mirror DM6 and incident on the PPLN crystal 303 via the beam diameter adjustment optical system 315 and the dichroic mirror DM7.

[0079] Furthermore, the pump laser light transmitted through the beam splitter BS2 is incident on the PPLN crystal 303 coaxially with the signal laser light via the mirror MR4, the beam diameter adjustment optical system 316, and the dichroic mirror DM7. As a result, the signal laser light is further amplified in the PPLN crystal 303 by optical parametric amplification. At this time, amplified light with the same wavelength as the signal laser light is generated in the PPLN crystal 303, but the beam diameter adjustment optical systems 315 and 316 adjust the pump laser light within the PPLN crystal 303 so that the beam waist diameter is 1.5 to 2.6 times that of the signal laser light. Therefore, the amplified light output from the PPLN crystal 303 has a divergence angle similar to that of the signal laser light transmitted through the PPLN crystal 303 (amplified light from the PPLN crystal 302).

[0080] The idler light output from the PPLN crystal 303 passes through the dichroic mirror DM8 and is absorbed by the damper 334. The amplified light and transmitted signal laser light output from the PPLN crystal 303 are reflected by the dichroic mirror DM8 and output from the amplification system 32 via mirror MR5. The subsequent operation of the wavelength conversion system 50 is the same as in Embodiment 1. Although Figure 6 illustrates an example of a three-stage optical parametric amplification, a configuration with four or more stages of amplification may also be adopted.

[0081] 4.3 Action and Effects According to Embodiment 2, damage to the PPLN crystal can be suppressed, the number of OPA stages can be increased, and a higher-power laser beam with a wavelength of approximately 1553 nm can be obtained.

[0082] 5. Modified Example 1 of Beam Diameter Adjustment Optical System 5.1 Configuration Figure 7 schematically shows a modified example 1 of the beam diameter adjustment optical system. Instead of the lens pair beam diameter adjustment optical system 311 described in Figure 3, the beam diameter adjustment optical system 310 shown in Figure 7 may be applied. The configuration of the beam diameter adjustment optical system 310 can be applied to one or more of the beam diameter adjustment optical systems 311 to 316 shown in Figures 2 and 6. The differences between the configuration in Figure 7 and that in Figure 3 will be explained below.

[0083] The beam diameter adjustment optical system 310 has a variable beam expander 350 with variable magnification positioned between opposing lens pairs (lenses 321 and 322). The variable beam expander 350 comprises lenses 351, 352, and 353, lens holders 361, 362, and 363, and uniaxial stages 364 and 365 that are movable parallel to the optical axis. The uniaxial stages 364 and 365 may be linear stages and each comprises a driver 366 and 367. The uniaxial stages 364 and 365 are driven via drivers 366 and 367 by commands from the solid-state laser control unit 60 and are configured to adjust the interlenticular distance of lenses 351, 352, and 353. Each of the uniaxial stages 364 and 365 is an example of a “lens movement mechanism” in this disclosure.

[0084] Lens 351 is held in lens holder 361 and positioned on base plate 326. Lens 351 may be a concave lens. Lenses 352 and 353 are held in lens holders 362 and 363, respectively, and fixed to uniaxial stages 364 and 365. The uniaxial stages 364 and 365 are positioned on base plate 326. Lenses 352 and 353 may each be convex lenses.

[0085] Although Figure 7 illustrates a variable beam expander 350 using three lenses 351, 352, and 353, the variable beam expander 350 may have a configuration including three or more lenses.

[0086] 5.2 Operation The solid-state laser control unit 60 controls the positions of the lenses 352 and 353 by sending commands to the drivers 366 and 367 to move the uniaxial stages 364 and 365 parallel to the optical axis. This allows the beam magnification to be adjusted while maintaining beam collimation.

[0087] 5.3 Action and Effects The beam diameter adjustment optical system 310 shown in Figure 7 constitutes a zoom system, making it easy to adjust the beam waist diameter without changing the beam waist position.

[0088] 5.4 Control Examples The positions of the single-axis stages 364 and 365 may be controlled by inputting the output from a beam diameter monitor, such as a beam profiler (not shown), which monitors the beam diameter of the pump laser beam and the signal laser beam in each optical path performing multi-stage optical parametric amplification, to the solid-state laser control unit 60. For example, the single-axis stages 364 and 365 may be controlled so that the beam waist diameters of the pump laser beam and the signal laser beam are approximately the same within the PPLN crystal 301, and further controlled so that the beam waist diameter of the pump laser beam within the PPLN crystal 302 is 1.5 to 2.6 times the beam waist diameter of the signal laser beam within the PPLN crystal 302.

[0089] With this configuration, the beam diameter adjustment optical system 310 can be controlled, so even if there are system fluctuations due to thermal load or the like, the appropriate beam waist diameter for each crystal can always be maintained.

[0090] 6. Modified Example 2 of Beam Diameter Adjustment Optical System Figure 8 schematically shows a second modified example of the beam diameter adjustment optical system. Instead of the beam diameter adjustment optical system 311, which is constructed using the lens pair described in Figure 3, the beam diameter adjustment optical system 340 shown in Figure 8 may be applied. The beam diameter adjustment optical system 340 can be applied to one or more of the beam diameter adjustment optical systems 311 to 316 shown in Figures 2 and 6. The beam diameter adjustment optical system 340 is composed of a mirror optical system including a plurality of concave mirrors 371, 372 instead of a lens pair. The beam diameter adjustment optical system 340 can suppress the thermal lensing effect caused by the absorption of laser light by the lenses.

[0091] 7. Laser systems using excimer amplifiers The solid-state laser system 10, including the laser system 100 described in each embodiment of Embodiment 1 and Embodiment 2, may be used in combination with an excimer amplifier (not shown).

[0092] In other words, a laser system 100 that outputs pulsed laser light amplified by an excimer amplifier may be configured by inputting the pulsed ultraviolet laser light output from the solid-state laser system 10 as seed light for the excimer amplifier.

[0093] The excimer amplifier may be, for example, a multipath amplifier in which pulsed laser light passes through a discharge space in a chamber filled with excimer laser gas multiple times (e.g., three times) for amplification, or it may be an amplifier equipped with an optical resonator such as a Fabry-Perot resonator or a ring resonator.

[0094] 8. Methods for manufacturing electronic devices Figure 9 schematically shows an example configuration of the exposure apparatus 800. The exposure apparatus 800 includes an illumination optical system 806 and a projection optical system 808. The laser system 110 is a laser system including the solid-state laser system 10 described in Embodiment 1 and Embodiment 2. The laser system 110 may also be configured by combining the solid-state laser system 10 with an excimer amplifier. The laser system 110 is used to generate ultraviolet laser light, which is output to the exposure apparatus 800. The illumination optical system 806 illuminates the reticle pattern of a reticle (not shown) placed on the reticle stage RT with the laser light incident from the laser system 110. The projection optical system 808 reduces and projects the laser light that has passed through the reticle onto a workpiece (not shown) placed on the workpiece table WT to form an image. The workpiece is a photosensitive substrate such as a semiconductor wafer coated with photoresist.

[0095] The exposure apparatus 800 exposes the workpiece to a laser beam reflecting the reticle pattern by synchronously moving the reticle stage RT and the workpiece table WT in opposite directions. After transferring the reticle pattern to the semiconductor wafer through the exposure process described above, a semiconductor device can be manufactured by going through several processes. The semiconductor device is an example of an "electronic device" in this disclosure.

[0096] 9. Other The above description is intended to be illustrative and not restrictive. Therefore, it will be apparent to those skilled in the art that modifications can be made to the embodiments of this disclosure without departing from the claims. It will also be apparent to those skilled in the art that the embodiments of this disclosure can be used in combination.

[0097] Terms used in this specification and throughout the claims should be interpreted as "non-limiting" unless otherwise specified. For example, terms such as "includes," "have," "equip," and "possess" should be interpreted as "not excluding the existence of components other than those described." Also, the modifier "one" should be interpreted as "at least one" or "one or more." Furthermore, 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." In addition, it should be interpreted as including combinations of these with anything other than "A," "B," and "C."

Claims

1. A pump laser device that outputs pump laser light of the first wavelength, A signal laser device that outputs signal laser light of a second wavelength longer than the first wavelength, The amplification system includes a plurality of optical parametric crystals that transmit the pump laser light and the signal laser light to output amplified light of the second wavelength, The plurality of optical parametric crystals include a first optical parametric crystal and a second optical parametric crystal arranged in series with the first optical parametric crystal. The aforementioned amplification system is, The beam waist positions of the first amplified light of the second wavelength, which is output from the first optical parametric crystal and incident on the second optical parametric crystal, and the pump laser light, which is incident on the second optical parametric crystal, coincide with each other, and the first amplified light and the pump laser light are arranged to be incident on the second optical parametric crystal coaxially. The invention provides a first beam diameter adjustment optical system in which the ratio of the beam waist diameter of the pump laser light in the second optical parametric crystal to the beam waist diameter of the first amplified light in the second optical parametric crystal is set to be greater than the ratio of the beam waist diameter of the pump laser light in the first optical parametric crystal to the beam waist diameter of the signal laser light in the first optical parametric crystal. Laser system.

2. The laser system according to claim 1, further, The aforementioned amplification system is, The beam waist positions of the signal laser beam incident on the first optical parametric crystal and the pump laser beam incident on the first optical parametric crystal coincide with each other, and the signal laser beam and the pump laser beam are arranged to be incident on the first optical parametric crystal coaxially. The system includes a second beam diameter adjustment optical system in which the beam waist diameter of the signal laser light in the first optical parametric crystal and the beam waist diameter of the pump laser light in the first optical parametric crystal are set to be the same diameter. Laser system.

3. A laser system according to claim 1, The ratio of the beam waist diameter of the pump laser light in the second optical parametric crystal to the beam waist diameter of the first amplified light in the second optical parametric crystal is in the range of 1.5 to 2.6 times. Laser system.

4. A laser system according to claim 1, The first beam diameter adjustment optical system is, A third beam diameter adjustment optical system is positioned on the optical path between the first optical parametric crystal and the second optical parametric crystal to adjust the beam waist diameter of the first amplified light, The system includes a fourth beam diameter adjustment optical system positioned on the optical path of the pump laser beam and adjusting the beam waist diameter of the pump laser beam incident on the second optical parametric crystal, Laser system.

5. A laser system according to claim 1, The divergence angle of the second amplified light of the second wavelength output from the second optical parametric crystal is 0.8 times or more and 1.2 times or less of the divergence angle of the first amplified light transmitted through the second optical parametric crystal and output from the second optical parametric crystal. Laser system.

6. A laser system according to claim 2, The second beam diameter adjustment optical system is, A fifth beam diameter adjustment optical system is positioned on the optical path of the signal laser light incident on the first optical parametric crystal and adjusts the beam waist diameter of the signal laser light, The system includes a sixth beam diameter adjustment optical system positioned on the optical path of the pump laser beam and adjusting the beam waist diameter of the pump laser beam incident on the first optical parametric crystal, Laser system.

7. A laser system according to claim 2, The signal laser beam incident on the first optical parametric crystal and the pump laser beam incident on the first optical parametric crystal are each set to have a beam waist at the center of the first optical parametric crystal, and the beam waist positions of each are set. The beam waist positions of the first amplified light of the second wavelength incident on the second optical parametric crystal and the pump laser light incident on the second optical parametric crystal are set so that the beam waist is at the center of the second optical parametric crystal. Laser system.

8. A laser system according to claim 1, The aforementioned amplification system is, Three or more of the optical parametric crystals, including the first optical parametric crystal and the second optical parametric crystal, are arranged in series. The plurality of optical parametric crystals are configured to perform optical parametric amplification in three or more stages, with the first optical parametric crystal being the first stage of the amplification stage. Laser system.

9. A laser system according to claim 8, The ratio of the beam waist diameter of the pump laser light to the beam waist diameter of the amplified light of the second wavelength in each optical parametric crystal positioned downstream of the first optical parametric crystal is in the range of 1.5 to 2.6 times. Laser system.

10. A laser system according to claim 1, The plurality of optical parametric crystals are arranged in series, and the beam waist diameter of the pump laser light incident on each of the plurality of optical parametric crystals performing multiple stages of optical parametric amplification is set such that the beam waist diameter of the pump laser light incident on the optical parametric crystal that is relatively located later in the series arrangement is larger. Laser system.

11. A laser system according to claim 10, In the series arrangement of the plurality of optical parametric crystals, the optical parametric crystal positioned relatively later has a larger crystal cross-sectional area perpendicular to the optical axis of the pump laser beam compared to the optical parametric crystal positioned relatively earlier. Laser system.

12. A laser system according to claim 1, The first beam diameter adjustment optical system is, It features a configuration in which a variable beam expander with variable magnification is positioned between opposing pairs of lenses. The variable beam expander includes three or more lenses and a lens movement mechanism for changing the distance between the three or more lenses. Laser system.

13. A laser system according to claim 2, The second beam diameter adjustment optical system is, It features a configuration in which a variable beam expander with variable magnification is positioned between opposing pairs of lenses. The variable beam expander includes three or more lenses and a lens movement mechanism for changing the distance between the three or more lenses. Laser system.

14. A laser system according to claim 1, The first beam diameter adjustment optical system is, Composed of a mirror optical system including multiple concave mirrors, Laser system.

15. A laser system according to claim 2, The second beam diameter adjustment optical system is, Composed of a mirror optical system including multiple concave mirrors, Laser system.

16. The laser system according to claim 1, further, The system includes a wavelength conversion system that takes the amplified light of the second wavelength output from the amplification system and ultraviolet light as incident light to output a sum frequency. Laser system.

17. The laser system according to claim 16, further, The invention includes a nonlinear optical crystal that receives the pump laser light of the first wavelength and converts its wavelength into ultraviolet light, which is a harmonic light. Laser system.

18. A laser system according to claim 16, The wavelength conversion system includes a plurality of nonlinear optical crystals arranged in series, Multiple sum-frequency generation is performed using the aforementioned multiple nonlinear optical crystals. Laser system.

19. A laser system according to claim 1, The pump laser device, A first semiconductor laser that outputs a first CW laser light of the first wavelength, The system includes a first solid-state amplifier that pulses and amplifies the first CW laser light, The pulsed laser light of the first wavelength output from the first solid-state amplifier is used as the pump laser light. The signal laser device is A second semiconductor laser that outputs a second CW laser light of the second wavelength, The system includes a second solid-state amplifier for amplifying the second CW laser light, The CW laser light of the second wavelength output from the second solid-state amplifier is used as the signal laser light. Laser system.

20. A method for manufacturing electronic devices, A pump laser device that outputs pump laser light of the first wavelength, A signal laser device that outputs signal laser light of a second wavelength longer than the first wavelength, The amplification system includes a plurality of optical parametric crystals that transmit the pump laser light and the signal laser light to output amplified light of the second wavelength, The plurality of optical parametric crystals include a first optical parametric crystal and a second optical parametric crystal arranged in series with the first optical parametric crystal. The aforementioned amplification system is, The beam waist positions of the first amplified light of the second wavelength, which is output from the first optical parametric crystal and incident on the second optical parametric crystal, and the pump laser light, which is incident on the second optical parametric crystal, coincide with each other, and the first amplified light and the pump laser light are arranged to be incident on the second optical parametric crystal coaxially. The laser system generates the second wavelength laser light by a laser system equipped with a first beam diameter adjustment optical system, wherein the ratio of the beam waist diameter of the pump laser light in the second optical parametric crystal to the beam waist diameter of the first amplified light in the second optical parametric crystal is set to be greater than the ratio of the beam waist diameter of the pump laser light in the first optical parametric crystal to the beam waist diameter of the signal laser light in the first optical parametric crystal. The aforementioned second wavelength laser light is converted to ultraviolet laser light, The aforementioned ultraviolet laser light is output to the exposure apparatus, A method for manufacturing an electronic device, comprising exposing a photosensitive substrate with ultraviolet laser light in an exposure apparatus for the purpose of manufacturing an electronic device.

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