Wavelength conversion system, solid-state laser system, and method for manufacturing electronic device

Abstract

A wavelength conversion system according to one aspect of the present disclosure is provided with: a first nonlinear optical crystal (51) on which first light (B1) having a first wavelength is incident and which outputs second light (B2) having a second wavelength, which is twice the first light; a second nonlinear optical crystal (52) on which the second light (B2) and third light (B3) having a third wavelength are incident, and which outputs fourth light (B4), which has a fourth wavelength and is a sum frequency light of the second light and the third light, and the third light (B3); a third nonlinear optical crystal (53) into which the third light (B3) and the fourth light (B4) are incident and which outputs fifth light (B5) having a fifth wavelength, which is the sum frequency light of the third light and the fourth light; and a converging optical system (55a) that causes the first light (B1) to enter the first nonlinear optical crystal (51) such that the waist position of the second light (B2) is disposed within the second nonlinear optical crystal (52). The first nonlinear optical crystal (51) is disposed within a Rayleigh length (zR2) of the second light from a beam waist position (P2) of the second light, and the third nonlinear optical crystal (53) is disposed within a Rayleigh length (zR4) of the fourth light from the beam waist position (P2) of the second light.

Description

Technical Field

[0001] The present disclosure relates to a wavelength conversion system, a solid-state laser system, and a method for manufacturing an electronic device. Background Art

[0002] In recent years, in semiconductor exposure devices, as semiconductor integrated circuits become smaller and more highly integrated, there is a demand for improved resolution. Therefore, the wavelength of light emitted from an exposure light source is being shortened. For example, as a gas laser device for exposure, a KrF excimer laser device that outputs a laser with a wavelength of about 248nm and an ArF excimer laser device that outputs a laser with a wavelength of about 193.4nm are used.

[0003] The spectral line width of the natural oscillation light of the KrF excimer laser device and the ArF excimer laser device is wide, at 350 to 400 pm. Therefore, if the projection lens is made of a material that allows ultraviolet rays such as KrF and ArF lasers to pass through, chromatic aberration may sometimes occur. As a result, the resolution may be reduced. Therefore, it is necessary to narrow the spectral line width of the laser output from the gas laser device to a level where the chromatic aberration can be ignored. Therefore, in order to narrow the spectral line width, a narrowing module (Line Narrowing Module) containing narrowing elements (etalon, grating, etc.) is sometimes provided in the laser resonator of the gas laser device. A gas laser device with a narrowed spectral line width like this is called a narrowed gas laser device.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: U.S. Patent No. 11226536

[0007] Patent Document 2: Japanese Patent Application Publication No. 2007-140564 Summary of the invention

[0008] A wavelength conversion system according to one aspect of the present disclosure comprises: a first nonlinear optical crystal into which first light having a first wavelength is incident and which outputs second light having a second wavelength which is a double wave of the first light; a second nonlinear optical crystal into which the second light and third light having a third wavelength are incident and which outputs fourth light and the third light, wherein the fourth light has a fourth wavelength and is a sum frequency light of the second light and the third light; a third nonlinear optical crystal into which the third light and fourth light are incident and which outputs fifth light having a fifth wavelength which is a sum frequency light of the third light and the fourth light; and a converging optical system which causes the first light to be incident on the first nonlinear optical crystal so that a beam waist position of the second light is arranged in the second nonlinear optical crystal, the first nonlinear optical crystal is arranged in a range within a Rayleigh length of the second light from the beam waist position of the second light, and the third nonlinear optical crystal is arranged in a range within a Rayleigh length of the fourth light from the beam waist position of the second light.

[0009] The solid-state laser system of one aspect of the present disclosure comprises: a wavelength conversion system; a signal laser system that outputs a signal laser; an amplification system that pulse-amplifies the signal laser based on a pump laser and outputs the pulse-amplified signal laser as a third light to the wavelength conversion system; and a pump laser device that generates a pump laser and a first light, outputs the pump laser to the amplification system, and outputs the first light to the wavelength conversion system, wherein the wavelength conversion system comprises: a first nonlinear optical crystal that receives a first light having a first wavelength and outputs a second light having a second wavelength that is a double wave of the first light; and a second nonlinear optical crystal that receives the second light and the first light having a first wavelength. A third light of three wavelengths is incident, and a fourth light and the third light are output, wherein the fourth light has a fourth wavelength and is a sum frequency light of the second light and the third light; a third nonlinear optical crystal is provided for the third light and the fourth light to be incident, and outputs a fifth light having a fifth wavelength which is a sum frequency light of the third light and the fourth light; and a converging optical system is provided, which allows the first light to be incident on the first nonlinear optical crystal, so that the beam waist position of the second light is arranged in the second nonlinear optical crystal, the first nonlinear optical crystal is arranged in a range within the Rayleigh length of the second light from the beam waist position of the second light, and the third nonlinear optical crystal is arranged in a range within the Rayleigh length of the fourth light from the beam waist position of the second light.

[0010] A method for manufacturing an electronic device according to one aspect of the present disclosure includes the following steps: generating laser light by a solid-state laser system including a wavelength conversion system, outputting the laser light to an exposure device, and exposing a photosensitive substrate to the laser light in the exposure device to manufacture the electronic device, wherein the wavelength conversion system includes: a first nonlinear optical crystal into which first light having a first wavelength is incident and outputs second light having a second wavelength which is a double wave of the first light; a second nonlinear optical crystal into which the second light and a third light having a third wavelength are incident and outputs fourth light and the third light, wherein the fourth light has a fourth wavelength and is a sum frequency light of the second light and the third light; a third nonlinear optical crystal into which the third light and the fourth light are incident and outputs fifth light having a fifth wavelength which is a sum frequency light of the third light and the fourth light; and a converging optical system that causes the first light to be incident on the first nonlinear optical crystal so that a beam waist position of the second light is arranged in the second nonlinear optical crystal, the first nonlinear optical crystal is arranged in a range within a Rayleigh length of the second light from the beam waist position of the second light, and the third nonlinear optical crystal is arranged in a range within a Rayleigh length of the fourth light from the beam waist position of the second light. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Hereinafter, several embodiments of the present disclosure will be described with reference to the accompanying drawings, merely as examples.

[0012] Figure 1 FIG. 1 is a diagram schematically showing the configuration of a solid-state laser system according to a comparative example.

[0013] Figure 2 It is a diagram schematically showing the structure of a wavelength conversion system of a comparative example.

[0014] Figure 3 This is a diagram schematically showing a unit having a nonlinear optical crystal arranged therein.

[0015] Figure 4 This is a diagram schematically showing the configuration of the wavelength conversion system according to the first embodiment.

[0016] Figure 5 is a graph showing the relationship between the Rayleigh length and the beam waist radius.

[0017] Figure 6 This is a diagram schematically showing the configuration of a wavelength conversion system according to the second embodiment.

[0018] Figure 7 This is a diagram schematically showing the structure of a periscope optical system.

[0019] Figure 8 This is a diagram schematically showing the configuration of a wavelength conversion system according to a fourth embodiment.

[0020] Fig. 9 This is a diagram schematically showing a configuration example of an exposure device. DETAILED DESCRIPTION

[0021] <Content>

[0022] 1. Comparative Example

[0023] 1.1 Solid-state laser system

[0024] 1.1.1 Structure

[0025] 1.1.2 Action

[0026] 1.2 Wavelength conversion system

[0027] 1.2.1 Structure and function

[0028] 1.3 Topics

[0029] 2. First Implementation

[0030] 2.1 Structure and function

[0031] 2.2 Relationship between Rayleigh length and numerical aperture

[0032] 2.3 Effect

[0033] 3. Second Implementation

[0034] 3.1 Structure and function

[0035] 3.2 Effect

[0036] 4. Third Implementation

[0037] 4.1 Structure and function

[0038] 4.2 Effect

[0039] 5. Fourth embodiment

[0040] 5.1 Structure and function

[0041] 5.2 Effect

[0042] 6. Method for manufacturing electronic devices

[0043] Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The embodiments described below represent several examples of the present disclosure and do not limit the content of the present disclosure. In addition, the structures and actions described in the embodiments may not all be necessary as the structures and actions of the present disclosure. In addition, the same reference symbols are marked on the same components, and repeated descriptions are omitted.

[0044] 1. Comparative Example

[0045] First, comparative examples of the present disclosure are described. The comparative examples of the present disclosure are methods that the applicant recognizes are only known to the applicant, and are not publicly known examples recognized by the applicant himself.

[0046] 1.1 Solid-state laser system

[0047] 1.1.1 Structure

[0048] Figure 1 The structure of a solid-state laser system 10 of a comparative example is schematically shown. The solid-state laser system 10 includes a signal laser device 2, an amplifier system 3, a pump laser device 4, a wavelength conversion system 5, and a solid-state laser control unit 6. The solid-state laser system 10 outputs pulsed laser light having a wavelength of approximately 193.4 nm.

[0049] The signal laser device 2 includes a semiconductor laser 21 and a solid-state amplifier 22. The semiconductor laser 21 performs CW (Continuous Wave) oscillation in a single longitudinal mode and outputs CW laser light with a wavelength of about 1553 nm. The solid-state amplifier 22 is an amplifier including a semiconductor optical amplifier, and amplifies the CW laser light output from the semiconductor laser 21. The CW laser light with a wavelength of about 1553 nm amplified by the solid-state amplifier 22 is incident on the amplification system 3 as the signal laser light S.

[0050] The pump laser device 4 includes a semiconductor laser 41, a solid-state amplifier 42, a LBO (LiB 3 O 5 ) crystal 43 and a dichroic mirror (DM: Dichroic Mirror) 44. The semiconductor laser 41 performs CW oscillation in a single longitudinal mode and outputs CW laser light with a wavelength of about 1030nm. The solid amplifier 42 is an amplifier including a semiconductor optical amplifier and a Yb-doped YAG crystal, and performs pulse amplification on the CW laser light output from the semiconductor laser 41.

[0051] The LBO crystal 43 is a nonlinear optical crystal, and converts the wavelength of the pulse laser light having a wavelength of about 1030 nm generated by pulse amplification by the solid-state amplifier 42 to generate a pulse laser light having a wavelength of about 515 nm as a doubled wave.

[0052] DM44 is arranged on the downstream side of the LBO crystal 43, and makes the pulsed laser with a wavelength of about 1030nm which is not wavelength-converted by the LBO crystal 43 highly reflective, and makes the pulsed laser with a wavelength of about 515nm incident from the LBO crystal 43 highly transparent. The pulsed laser after being highly reflected by DM44 is output from the pump laser device 4 and incident on the amplification system 3 as the pump laser P. The pulsed laser after being highly transparent to DM44 is output from the pump laser device 4 and incident on the wavelength conversion system 5 as the first pulsed laser PL1.

[0053] The amplification system 3 includes an optical parametric amplifier (OPA). The OPA is an amplifier including, for example, a periodically polarized reversed lithium niobate crystal (PPLN), a periodically polarized reversed potassium titanyl phosphate crystal (PPKTP), etc. The OPA performs pulse amplification on the signal laser S incident from the signal laser device 2 based on the pump laser P incident from the pump laser device 4. The pulse-amplified signal laser S is output from the amplification system 3 and incident on the wavelength conversion system 5 as the second pulse laser PL2.

[0054] The wavelength conversion system 5 includes a first CLBO (CsLiB 6 O 10 ) crystal 51, a second CLBO crystal 52, a third CLBO crystal 53 and DM54a. The first CLBO crystal 51 is a nonlinear optical crystal that converts the wavelength of the first pulse laser PL1 incident from the pump laser device 4, generates and outputs an ultraviolet pulse laser with a wavelength of about 257.5nm as a double wave of the first pulse laser PL1.

[0055] DM54a is arranged on the downstream side of the first CLBO crystal 51, and makes the second pulse laser PL2 incident from the amplification system 3 highly reflected, and makes the ultraviolet pulse laser incident from the first CLBO crystal 51 highly transparent. In addition, DM54a is arranged so that the highly reflected second pulse laser PL2 and the highly transparent ultraviolet pulse laser are incident on the second CLBO crystal 52 coaxially.

[0056] The second CLBO crystal 52 and the third CLBO crystal 53 are arranged in series, and generate and output pulsed laser PL with a wavelength of about 193.4 nm by generating two sum frequencies.

[0057] The solid-state laser control unit 6 is constituted by a processor and is connected to the signal laser device 2, the pump laser device 4, and the wavelength conversion system 5. The solid-state laser control unit 6 is connected to a laser control unit 12 provided outside the solid-state laser system 10.

[0058] 1.1.2 Action

[0059] Next, the operation of the solid-state laser system 10 of the comparative example is described. The solid-state laser control unit 6 controls the current value of the semiconductor laser 41 of the pump laser device 4 to make it perform CW oscillation and output a CW laser with a wavelength of about 1030nm. In addition, the solid-state laser control unit 6 amplifies the pulses of the CW laser output from the semiconductor laser 41 through the solid-state amplifier 42.

[0060] The LBO crystal 43 converts the pulse laser with a wavelength of about 1030 nm generated by pulse amplification by the solid amplifier 42 into a pulse laser with a wavelength of about 515 nm. The pulse laser with a wavelength of about 515 nm is highly transmitted through the DM44 and enters the wavelength conversion system 5 as the first pulse laser PL1. In addition, the pulse laser with a wavelength of about 1030 nm that has not been wavelength-converted by the LBO crystal 43 is highly reflected by the DM44 and enters the amplification system 3 as the pump laser P.

[0061] The solid laser control unit 6 controls the current value of the semiconductor laser 21 of the signal laser device 2 to make it perform CW oscillation and output CW laser light with a wavelength of about 1553nm. In addition, the solid laser control unit 6 amplifies the CW laser light output from the semiconductor laser 21 through the solid amplifier 22. Thus, the CW laser light with a wavelength of about 1553nm is output from the signal laser device 2 and is incident on the amplification system 3 as the signal laser light S.

[0062] The amplification system 3 performs pulse amplification on the signal laser light S based on the pump laser light P. The pulse-amplified signal laser light S is incident on the wavelength conversion system 5 as the second pulse laser light PL2 .

[0063] In the wavelength conversion system 5, the first pulse laser PL1 is converted into an ultraviolet pulse laser with a wavelength of about 257.5 nm by the first CLBO crystal 51. The ultraviolet pulse laser with a wavelength of about 257.5 nm is highly transmitted through DM54a and incident on the second CLBO crystal 52. The second pulse laser PL2 is highly reflected by DM54a and incident on the second CLBO crystal 52. The second CLBO crystal 52 generates and outputs an ultraviolet pulse laser with a wavelength of about 220.9 nm, which is a sum frequency light of the second pulse laser PL2 and the ultraviolet pulse laser with a wavelength of about 257.5 nm. In addition, the second CLBO crystal 52 outputs the second pulse laser PL2 that has not been wavelength-converted.

[0064] The second pulsed laser PL2 outputted from the second CLBO crystal 52 and the ultraviolet pulsed laser light having a wavelength of about 220.9 nm are coaxially incident on the third CLBO crystal 53. The third CLBO crystal 53 generates and outputs the pulsed laser PL having a wavelength of about 193.4 nm as the sum frequency light of the second pulsed laser PL2 and the ultraviolet pulsed laser light having a wavelength of about 220.9 nm. The pulsed laser PL is outputted from the solid-state laser system 10.

[0065] The pulse laser light PL output from the solid-state laser system 10 may be amplified by an excimer amplifier (not shown).

[0066] 1.2 Wavelength conversion system

[0067] 1.2.1 Structure and function

[0068] Next, use Figure 2 The structure and function of the wavelength conversion system 5 of the comparative example will be described in more detail. Figure 2 The structure of the wavelength conversion system 5 of the comparative example is shown. The wavelength conversion system 5 includes DM54b, 54c, lenses 55a-55c, high reflection mirrors 56a, 56b and a half-wave plate 57 in addition to the first to third CLBO crystals 51 to 53 and DM54a described above.

[0069] The first to third CLBO crystals 51 to 53 are nonlinear optical crystals having a phase matching condition of type 1. That is, the first to third CLBO crystals 51 to 53 are configured so that the angle between the optical axis and the optical path axis of the incident laser beam becomes a phase matching angle satisfying the phase matching condition of type 1.

[0070] The lens 55a is arranged on the optical path of the first light B1 incident on the wavelength conversion system 5 and on the upstream side of the first CLBO crystal 51. The first light B1 is the first pulsed laser PL1 described above. The first light B1 has a first wavelength λ 1 The lens 55 a converges the first light B1 so that the beam waist position P1 of the first light B1 is located in the first CLBO crystal 51 .

[0071] The first CLBO crystal 51 is arranged so that the center of the crystal becomes the beam waist position P1. 1 The first light B1 is converted into a second wavelength λ which is a double wave of the first light B1. 2 The second light B2 is output. The second wavelength λ 2 The second light B2 is the ultraviolet pulse laser light having a wavelength of about 257.5 nm. The first CLBO crystal 51 is an example of the “first nonlinear optical crystal” of the technology disclosed herein.

[0072] The beam waist position of the second light B2 is the same as the beam waist position P1 of the first light B1. That is, the second light B2 output from the first CLBO crystal 51 becomes diffused light diffused from the beam waist position P1.

[0073] The lens 55b is arranged on the optical path of the third light B3 incident on the wavelength conversion system 5 and on the upstream side of DM54a. The third light B3 is the second pulsed laser PL2 described above. The third light B3 has a third wavelength λ 3 The lens 55 b converges the third light B3 via the DM54 a so that the beam waist position P3 a of the third light B3 is located within the second CLBO crystal 52 .

[0074] DM54a is coated with a film that allows the second light B2 to be highly transmitted and the third light B3 to be highly reflected. The third light B3 that is incident on DM54a from the lens 55b and is highly reflected by DM54a is converged in the second CLBO crystal 52.

[0075] The second CLBO crystal 52 is arranged so that the center of the crystal becomes the beam waist position P3a. The second CLBO crystal 52 generates and outputs the fourth light B4, which is the sum frequency light of the second light B2 after high transmission through DM54a and the third light B3 after high reflection by DM54a. The fourth wavelength λ of the fourth light B4 is 4 It is about 220.9 nm. In addition, the second CLBO crystal 52 outputs the third light B3 which is not wavelength-converted. The second CLBO crystal 52 is an example of the "second nonlinear optical crystal" of the technology disclosed in the present invention.

[0076] The second light B2 and the third light B3 incident on the second CLBO crystal 52 are both linearly polarized lights. Since the second CLBO crystal 52 has a type-1 phase matching condition, it is necessary to make the polarization direction of the second light B2 incident on the second CLBO crystal 52 parallel to the polarization direction of the third light B3. When the polarization direction of the second light B2 incident on the second CLBO crystal 52 is parallel to the polarization direction of the third light B3, the polarization direction of the third light B3 output from the second CLBO crystal 52 is perpendicular to the polarization direction of the fourth light B4.

[0077] The third CLBO crystal 53 has a type-1 phase matching condition, so the polarization direction of the third light B3 incident on the third CLBO crystal 53 needs to be parallel to the polarization direction of the fourth light B4. Since the polarization direction of the third light B3 output from the second CLBO crystal 52 is perpendicular to the polarization direction of the fourth light B4, the polarization direction of either the third light B3 or the fourth light B4 needs to be rotated 90°.

[0078] DM54b, 54c, lens 55c, high reflective mirrors 56a, 56b and 1 / 2 wavelength plate 57 constitute a polarization direction changing optical system 60. The polarization direction changing optical system 60 is arranged between the second CLBO crystal 52 and the third CLBO crystal 53. In this comparative example, the polarization direction changing optical system 60 rotates the polarization direction of the third light B3 by 90° so that the polarization direction of the third light B3 is parallel to the polarization direction of the fourth light B4.

[0079] DM54b and 54c are coated with films that make the fourth light B4 highly transparent and the third light B3 highly reflective, respectively. DM54b is arranged on the downstream side of the second CLBO crystal 52, and is an optical path separation element that separates the optical paths of the third light B3 and the fourth light B4 output from the second CLBO crystal 52. DM54c is arranged on the upstream side of the third CLBO crystal 53, and is an optical path merging element that merges the optical paths of the third light B3 and the fourth light B4 after the optical paths are separated by DM54b.

[0080] DM54b highly transmits the fourth light B4 output from the second CLBO crystal 52. The fourth light B4 highly transmitted through DM54b highly transmits DM54c and enters the third CLBO crystal 53. DM54b highly reflects the third light B3 output from the second CLBO crystal 52.

[0081] The high reflector 56a is arranged on the optical path of the third light B3 after being highly reflected by DM54b, so that the third light B3 is highly reflected. The lens 55c is arranged on the downstream side of the high reflector 56a, and the third light B3 is converged by the high reflector 56a and DM54c, and the beam waist position P3b of the third light B3 after being highly reflected by the high reflector 56a is located in the third CLBO crystal 53.

[0082] The high reflector 56b is arranged downstream of the lens 55c to highly reflect the third light B3. The half-wave plate 57 is arranged downstream of the high reflector 56b to rotate the polarization direction of the third light B3 highly reflected by the high reflector 56b by 90 degrees.

[0083] DM54c is arranged downstream of the half-wave plate 57, and highly reflects the third light B3 after the polarization direction is rotated by 90 degrees and makes it incident on the third CLBO crystal 53. As a result, the polarization direction of the third light B3 incident on the third CLBO crystal 53 is parallel to the polarization direction of the fourth light B4.

[0084] The third CLBO crystal 53 is arranged so that the center of the crystal becomes the beam waist position P3b. The third CLBO crystal 53 generates and outputs the fifth light B5 which is the sum frequency light of the third light B3 and the fourth light B4. The fifth light B5 is the pulse laser PL described above. The fifth wavelength λ of the fifth light B5 is 5 The third CLBO crystal 53 is an example of the "third nonlinear optical crystal" of the technology disclosed in the present invention. 1 ~Fifth wavelength λ 5 With λ 3 >λ 1 >λ 2 >λ 4 >λ 5 relationship.

[0085] The second CLBO crystal 52 is arranged in a range where the second light B2 as incident ultraviolet light can be regarded as parallel light. The third CLBO crystal 53 is arranged in a range where the fourth light B4 as incident ultraviolet light can be regarded as parallel light. Since the second light B2 and the fourth light B4 are diffused light diffused from the beam waist position P1, the second CLBO crystal 52 and the third CLBO crystal 53 are arranged at the Rayleigh length z on the downstream side of the beam waist position P1. R1 The Rayleigh length indicates the distance at which a pulsed laser can be regarded as parallel light.

[0086] 1.3 Topics

[0087] Next, the problem of the wavelength conversion system 5 of the comparative example will be described. Nonlinear optical crystals such as CLBO crystals are hygroscopic, so they are arranged in Figure 3 The interior of unit 70 is shown.

[0088] The unit 70 is configured to include a housing 71, an incident window 72, an exit window 73, a crystal holder 74, and a heater 75. The incident window 72 and the exit window 73 are mounted on the housing 71. The crystal holder 74 is disposed inside the housing 71 and holds a nonlinear optical crystal on the optical path of the pulsed laser passing through the incident window 72 and the exit window 73. The heater 75 is mounted on the crystal holder 74 and is connected to a heater power supply 76 disposed outside the unit 70. The heater 75 heats the nonlinear optical crystal.

[0089] The housing 71 is connected to a gas introduction pipe 77a for introducing a purge gas such as Ar gas into the housing 71 and a gas exhaust pipe 77b for exhausting the purge gas from the housing 71. The gas introduction pipe 77a is connected to a gas supply device 78a. The gas exhaust pipe 77b is connected to a gas exhaust device 78b.

[0090] The unit 70 is used while being purged with a purge gas and the temperature of the nonlinear optical crystal is maintained at about 150° C. by the heater 75. Therefore, in order to arrange the first to third CLBO crystals 51 to 53 in the wavelength conversion system 5, the volume of the unit 70 must be considered, and an optical path length for arranging the unit 70 must be ensured before and after the nonlinear optical crystal.

[0091] In order to ensure the optical path length for the configuration unit 70, the use of a relay lens optical system is considered. However, when the relay lens optical system is used, the relay lens optical system must transmit the pulse laser as ultraviolet light, so the lens is degraded by the ultraviolet light. As a result, the life of the wavelength conversion system 5 is shortened. In addition, due to the thermal lens effect caused by the absorption of ultraviolet light by the lens, the beam diameter and the beam waist position change. Furthermore, due to the surface reflection generated in the lens, the output of the pulse laser is reduced. Based on the above reasons, it is not preferred to use a relay lens optical system.

[0092] From the viewpoint of improving the efficiency of wavelength conversion, it is preferable to arrange the plurality of nonlinear optical crystals included in the wavelength conversion system 5 within the Rayleigh length from the beam waist position of the incident pulsed laser. Figure 2 In the example shown, as described above, the second CLBO crystal 52 and the third CLBO crystal 53 are arranged at the Rayleigh length z downstream from the beam waist position P1 located at the crystal center of the first CLBO crystal 51. R1 Within the range.

[0093] However, if the volume of the unit 70 is also considered, it is difficult to arrange each nonlinear optical crystal within the range of the Rayleigh length. Figure 2 In the example shown, if the volume of the unit cell 70 is taken into consideration, it is difficult to extend the Rayleigh length z from the first CLBO crystal 51 to R1 The second CLBO crystal 52 and the third CLBO crystal 53 are arranged within the range.

[0094] That is, in the wavelength conversion system 5 including a plurality of hygroscopic nonlinear optical crystals such as CLBO crystals, there is a problem that the optical path length in which the plurality of nonlinear optical crystals can be arranged is short and the degree of design freedom is very low from the viewpoint of improving the efficiency of wavelength conversion.

[0095] 2. First Implementation

[0096] Next, the solid-state laser system 10 of the first embodiment of the present disclosure is described. The solid-state laser system 10 of the first embodiment differs from the solid-state laser system 10 of the comparative example only in the structure of the wavelength conversion system. Hereinafter, the same reference numerals are given to the same components as those of the comparative example, and the description thereof is appropriately omitted.

[0097] 2.1 Structure and function

[0098] use Figure 4 The structure and function of the wavelength conversion system 5a according to the first embodiment will be described. Figure 4The structure of the wavelength conversion system 5a of the first embodiment is shown. The wavelength conversion system 5a includes first to third CLBO crystals 51 to 53, DM54a to 54c, lenses 55a to 55c, high reflection mirrors 56a and 56b, and a half-wave plate 57, similarly to the wavelength conversion system 5 of the comparative example.

[0099] In the present embodiment, the lens 55a causes the first light B1 to be incident on the first CLBO crystal 51, so that the beam waist position P2 of the second light B2 generated by the first CLBO crystal 51 is arranged in the second CLBO crystal 52. That is, the first light B1 is converged by the lens 55a, so that the second light B2 is converged in the second CLBO crystal 52. The second CLBO crystal 52 is preferably configured in such a way that the center of the crystal becomes the beam waist position P2. The lens 55a is an example of a "converging optical system" of the technology disclosed in the present invention. The converging optical system is not limited to one lens, and can also be composed of an optical system including two or more lenses, mirrors, etc.

[0100] In this embodiment, the beam waist position of the fourth light B4 generated by the second CLBO crystal 52 is the same as the beam waist position P2 of the second light B2. That is, the fourth light B4 output from the second CLBO crystal 52 becomes diffused light diffused from the beam waist position P2.

[0101] In this embodiment, the first CLBO crystal 51 is arranged on the upstream side of the second CLBO crystal 52 and the Rayleigh length z of the second light B2 from the beam waist position P2 is R2 Specifically, the light incident surface 51a of the first CLBO crystal 51 is located at the Rayleigh length z of the second light B2 from the beam waist position P2. R2 The first CLBO crystal 51 is arranged in a manner within a range of .

[0102] In addition, the third CLBO crystal 53 is arranged on the downstream side of the second CLBO crystal 52 and the Rayleigh length z of the fourth light B4 from the beam waist position P2 is R4 Specifically, the light emitting surface 53a of the third CLBO crystal 53 is at the Rayleigh length z of the fourth light B4 from the beam waist position P2. R4 The third CLBO crystal 53 is configured in a manner within the range.

[0103] 2.2 Relationship between Rayleigh length and numerical aperture

[0104] Next, the relationship between the Rayleigh length and the numerical aperture will be described. Figure 5 The Rayleigh length z when the laser light as collimated light enters the lens 90 is shown. R The relationship with the beam waist radius ω.

[0105] The beam waist of the laser beam focused by the lens 90 is generated at a position that is a focal length f from the lens 90. The beam waist radius ω is the beam radius of the laser beam at the beam waist position. More specifically, the beam waist radius ω is the radiation intensity that is 1 / e of the peak radiation intensity at the center of the beam. 2 times the beam radius at that position.

[0106] Rayleigh length z R The relationship with the beam waist radius ω is expressed by the following equation (1): Here, λ is the wavelength of the parallel light incident on the lens 90 .

[0107]

[0108] The relationship between the numerical aperture NA and the beam waist radius ω is expressed by the following equation (2): n is the refractive index of the medium in which the laser light propagates, and θ is the beam divergence angle.

[0109]

[0110] When n=1 and |θ|<<1, the above formula (2) is expressed by the following formula (3).

[0111]

[0112] In addition, based on the above formula (1), the beam waist radius ω is expressed by the following formula (4).

[0113]

[0114] like Figure 4 As shown in FIG. 1 , the distance from the light incident surface 51a of the first CLBO crystal 51 to the beam waist position P2 is set to L 1 In order to set the light incident surface 51a at the Rayleigh length z of the second light B2 from the beam waist position P2, R2 Within the range of , the following formula (5) must be satisfied. Here, ω 2 is the beam waist radius of the second light B2.

[0115]

[0116] According to the above formula (5), the beam waist radius ω of the second light B2 is 2 The following formula (6) needs to be satisfied.

[0117]

[0118] According to the above equations (3) and (6), in order to satisfy the above equation (5), the numerical aperture NA of the second light B2 is 2 It only needs to satisfy the following formula (7).

[0119]

[0120] In addition, if Figure 4 As shown in FIG. 1 , the distance from the light emitting surface 53a of the third CLBO crystal 53 to the beam waist position P2 is set to L 2 In order to set the light emitting surface 53a at the Rayleigh length z of the fourth light B4 from the beam waist position P2, R4 Within the range of , the following formula (8) must be satisfied. 4 is the beam waist radius of the fourth light B4.

[0121]

[0122] Here, assuming that ω 4 =ω 2 When , the above formula (8) is expressed by the following formula (9).

[0123]

[0124] Furthermore, it is assumed that the beam waist position of the first light B1 is consistent with the beam waist position P2 of the second light B2, and the beam waist radius ω of the first light B1 is 1 The following formula (10) is satisfied.

[0125]

[0126] In this case, the numerical aperture NA of the first light B1 is 1 It is represented by the following formula (11).

[0127]

[0128] Therefore, in this embodiment, for the distance L 1 The beam waist radius ω of the second light B2 is set to satisfy the above formula (6): 2 , the numerical aperture NA of the second light B2 is set in a manner that satisfies the above formula (7): 2 Furthermore, the lens 55a for converging the first light B1 only needs to have a beam waist radius ω of the first light B1. 1 Satisfies the above formula (10), and the numerical aperture NA 1 is the numerical aperture NA of the second light B2 2 √2 times of .

[0129] That is, as the lens 55a, it is sufficient to select a lens having a numerical aperture NA expressed by the following formula (12): 1 The lens can be used.

[0130]

[0131] 2.3 Effect

[0132] As described above, in the wavelength conversion system 5a of this embodiment, the lens 55a allows the first light B1 to enter the first CLBO crystal 51 so that the beam waist position P2 of the second light B2 generated by the first CLBO crystal 51 is arranged in the second CLBO crystal 52. Therefore, the Rayleigh length z of the second light B2 from the beam waist position P2 to the upstream side can be R2 The first CLBO crystal 51 can be arranged within a range of . In addition, the Rayleigh length z of the fourth light B4 from the beam waist position P2 to the downstream side can be R4 The third CLBO crystal 53 is arranged within the range of . By arranging all the first CLBO crystal 51 to the third CLBO crystal 53 within the range of the Rayleigh length z from the beam waist position P2 R2 、z R4 Within the range of a predetermined optical path length, the wavelength conversion efficiency is improved.

[0133] Thus, according to the present embodiment, the optical path length of the plurality of nonlinear optical crystals can be extended from the viewpoint of improving the efficiency of wavelength conversion, thereby increasing the degree of freedom in designing the wavelength conversion system 5a without reducing the wavelength conversion efficiency. As a result, the plurality of nonlinear optical crystals can be arranged inside the unit without using a relay lens optical system.

[0134] 3. Second Implementation

[0135] Next, a solid-state laser system 10 according to a second embodiment of the present disclosure is described. The solid-state laser system 10 according to the second embodiment differs from the solid-state laser system 10 according to the first embodiment only in the structure of the wavelength conversion system. Hereinafter, the same reference numerals are given to the same components as those in the first embodiment, and the description thereof is appropriately omitted.

[0136] 3.1 Structure and function

[0137] use Figure 6 The structure and function of the wavelength conversion system 5b according to the second embodiment will be described. Figure 6 The structure of the wavelength conversion system 5b of the second embodiment is shown. The wavelength conversion system 5b includes the first CLBO crystal 51 to the third CLBO crystal 53, DM54a to 54e, lenses 55a to 55c, a high reflection mirror 56b, a 1 / 2 wavelength plate 57 and attenuators 58a to 58c. As in the first embodiment, the first CLBO crystal 51 to the third CLBO crystal 53 are nonlinear optical crystals having a phase matching condition of type-1.

[0138] In the first embodiment, the first to third CLBO crystals 51 to 53 are arranged in a straight line, but in this embodiment, the first to third CLBO crystals 51 to 53 are arranged in a non-linear line. In addition, in this embodiment, the light not wavelength-converted by the first to third CLBO crystals 51 to 53 is absorbed by the attenuators 58a to 58c.

[0139] In this embodiment, the lens 55a also allows the first light B1 to enter the first CLBO crystal 51, so that the beam waist position P2 of the second light B2 generated by the first CLBO crystal 51 is arranged in the second CLBO crystal 52. The first CLBO crystal 51 is arranged at the Rayleigh length z of the second light B2 from the beam waist position P2 to the upstream side. R2 In addition, the third CLBO crystal 53 is arranged at the Rayleigh length z of the fourth light B4 from the beam waist position P2 to the downstream side. R4 When the optical paths of the second light B2 and the fourth light B4 are bent as in this embodiment, the Rayleigh length z R2 、z R4 Specified by the optical path length along a curved optical path.

[0140] In this embodiment, DM54a is coated with a film that makes the second light B2 highly reflective and the first light B1 and the third light B3 highly transparent. The second light B2 incident on the first CLBO crystal 51 from the lens 55a and generated in the first CLBO crystal 51 is highly reflected by DM54a and converged in the second CLBO crystal 52. The third light B3 incident on DM54a from the lens 55b is highly transparent to DM54a and converged in the second CLBO crystal 52.

[0141] The attenuator 58 a is disposed on the optical path of the first light B1 which has not been wavelength-converted by the first CLBO crystal 51 and has highly transmitted through the DM54 a , and absorbs the first light B1 .

[0142] The second CLBO crystal 52 is disposed on the optical path of the second light B2 highly reflected by DM54a and the third light B3 highly transmitted through DM54a. As in the first embodiment, the second CLBO crystal 52 generates the fourth light B4 which is the sum frequency light of the second light B2 and the third light B3.

[0143] In this embodiment, the polarization direction changing optical system 60a is composed of DM54b to 54d, lens 55c, high reflector 56b and 1 / 2 wavelength plate 57. The fourth light B4 output from the second CLBO crystal 52 and the second light B2 and the third light B3 that are not wavelength-converted by the second CLBO crystal 52 are incident on the polarization direction changing optical system 60a.

[0144] As in the first embodiment, DM54b is an optical path branching element. In this embodiment, DM54b is arranged on the downstream side of the second CLBO crystal 52, and highly reflects the second light B2 and the fourth light B4, and highly transmits the third light B3.

[0145] DM54d is disposed on the optical path of the second light B2 and the fourth light B4 after being highly reflected by DM54b, and highly reflects the fourth light B4 and highly transmits the second light B2. Attenuator 58b is disposed on the optical path of the second light B2 after being highly transmitted by DM54d, and absorbs the second light B2.

[0146] The lens 55c is arranged on the optical path of the third light B3 after the high transmission DM54b, and converges the third light B3 into the third CLBO crystal 53. The high reflection mirror 56b is arranged on the downstream side of the lens 55c, and makes the third light B3 highly reflected. The 1 / 2 wavelength plate 57 is arranged on the downstream side of the high reflection mirror 56b, and rotates the polarization direction of the third light B3 after the high reflection by the high reflection mirror 56b by 90°.

[0147] As in the first embodiment, DM54c is an optical path converging element. In this embodiment, DM54c is arranged on the downstream side of the 1 / 2 wavelength plate 57, so that the third light B3 after the polarization direction is rotated by 90° is highly transmitted and incident on the third CLBO crystal 53. In addition, DM54c is arranged on the optical path of the fourth light B4 after high reflection by DM54d, so that the fourth light B4 is highly reflected and incident on the third CLBO crystal 53.

[0148] The third CLBO crystal 53 generates and outputs the fifth light B5 which is the sum frequency light of the third light B3 and the fourth light B4. DM54e is arranged on the downstream side of the third CLBO crystal 53, so that the fifth light B5 is highly reflected and the third light B3 and the fourth light B4 are highly transmitted. Attenuator 58c is arranged on the optical path of the third light B3 and the fourth light B4 after the high transmission of DM54e, and absorbs the third light B3 and the fourth light B4.

[0149] In addition, the relationship between reflection and transmission of each of DM54a to 54e may be opposite to the above relationship. That is, the arrangement of the plurality of components included in the wavelength conversion system 5b can be modified in various ways.

[0150] 3.2 Effect

[0151] The wavelength conversion system 5b of this embodiment can be configured with a plurality of nonlinear optical crystals to increase the optical path length from the viewpoint of improving the efficiency of wavelength conversion, similarly to the wavelength conversion system 5a of the first embodiment. This increases the degree of freedom in design, and thus dichroic mirrors, attenuators, etc. can be efficiently configured.

[0152] 4. Third Implementation

[0153] Next, a solid-state laser system 10 according to a third embodiment of the present disclosure will be described. The solid-state laser system 10 according to the third embodiment is different from the solid-state laser system 10 according to the first embodiment only in the configuration of a wavelength conversion system.

[0154] 4.1 Structure and function

[0155] The wavelength conversion system of this embodiment uses a wavelength conversion system 5a in the first embodiment instead of the half-wavelength plate 57 included in the polarization direction changing optical system 60. Figure 7 The periscope optical system 80 is shown. Figure 7 , reference symbol D represents the polarization direction of the third light B3. The X direction, the Y direction, and the Z direction are directions perpendicular to each other.

[0156] The periscope optical system 80 includes a first periscope 81 and a second periscope 82. The first periscope 81 is arranged on the optical path of the third light B3, and deflects the optical path by 90° by making the third light B3 highly reflected. The second periscope 82 is arranged on the optical path of the third light B3 after being highly reflected by the first periscope 81, and deflects the optical path by 90° by making the third light B3 highly reflected. The second periscope 82 is arranged to reflect the third light B3 in a direction perpendicular to the incident direction of the third light B3 to the first periscope 81.

[0157] The third light B3 travels along the X direction and enters the first periscope 81, and is highly reflected by the first periscope 81 in the Z direction. At this time, the polarization direction D of the third light B3 is the Y direction. The high reflection by the first periscope 81 changes the optical path of the third light B3, but does not change the polarization direction D. The third light B3 highly reflected by the first periscope 81 travels along the Z direction and enters the second periscope 82, and is highly reflected by the second periscope 82 in the Y direction. The polarization direction D rotates 90° by the high reflection by the second periscope 82.

[0158] In this way, the periscope optical system 80 can rotate the polarization direction of the third light B3 by 90 degrees, similarly to the half-wavelength plate 57. In addition, the periscope optical system 80 may be configured using three or more periscopes.

[0159] 4.2 Effect

[0160] The half-wave plate 57 is a light-transmitting element, so the polarization direction may be affected by thermal load. In contrast, since the periscope optical system 80 is composed of a periscope as a light-reflecting element, it is not easy to generate thermal load, and the influence of thermal load on the polarization direction can be suppressed.

[0161] In addition, a periscope optical system 80 may be used instead of the half-wave plate 57 included in the polarization direction changing optical system 60a of the wavelength conversion system 5b of the second embodiment.

[0162] 5. Fourth embodiment

[0163] Next, a solid-state laser system 10 according to a fourth embodiment of the present disclosure is described. The solid-state laser system 10 according to the fourth embodiment differs from the solid-state laser system 10 according to the second embodiment only in the structure of the wavelength conversion system. Hereinafter, the same reference numerals are given to the same components as those in the second embodiment, and the description thereof is appropriately omitted.

[0164] 5.1 Structure and function

[0165] use Figure 8 The structure and function of the wavelength conversion system 5c according to the fourth embodiment will be described. Figure 8 The structure of the wavelength conversion system 5c of the fourth embodiment is shown. The wavelength conversion system 5c includes first to third CLBO crystals 51 to 53, DMs 54a, 54d, and 54e, lenses 55a and 55b, a high reflection mirror 56d, and attenuators 58a to 58c.

[0166] In this embodiment, the first CLBO crystal 51 and the third CLBO crystal 53 are nonlinear optical crystals having a phase matching condition of type 1, respectively. The second CLBO crystal 52 is a nonlinear optical crystal having a phase matching condition of type 2. The second CLBO crystal 52 is configured such that the angle between the optical axis and the optical path axis of the incident laser light becomes a phase matching angle that satisfies the phase matching condition of type 2.

[0167] In this embodiment, since the second CLBO crystal 52 has a type-2 phase matching condition, the polarization directions of the second light B2 and the third light B3 incident on the second CLBO crystal 52 are perpendicular to each other. As a result, the polarization directions of the third light B3 and the fourth light B4 output from the second CLBO crystal 52 are parallel, so there is no need to set the polarization direction changing optical system 60a as in the second embodiment.

[0168] Therefore, the polarization direction changing optical system 60a is not provided in the wavelength conversion system 5c. DM54d is arranged downstream of the second CLBO crystal 52, which makes the second light B2 highly reflected and makes the third light B3 and the fourth light B4 highly transmitted. The third light B3 and the fourth light B4 which have been highly transmitted through DM54d are incident on the third CLBO crystal 53 in a state where the polarization directions are parallel. The attenuator 58b is arranged on the optical path of the second light B2 which has been highly reflected by DM54d, and absorbs the second light B2.

[0169] DM54e is arranged on the downstream side of the third CLBO crystal 53, and highly reflects the fifth light B5, and highly transmits the third light B3 and the fourth light B4. The high reflector 56d is arranged on the optical path of the fifth light B5 highly reflected by DM54e, and highly reflects the fifth light B5.

[0170] In the present embodiment, since the lens 55 c is not provided, the lens 55 b is configured to converge the third light B3 between the second CLBO crystal 52 and the third CLBO crystal 53 .

[0171] The other structures of the wavelength conversion system 5c are the same as those of the wavelength conversion system 5b. In addition, the relationship between the reflection and transmission of each of DM54a, 54d, and 54e can also be opposite to the above relationship. That is, the configuration of the multiple components included in the wavelength conversion system 5c can be variously deformed. In addition, the high reflector 56d is not an essential component.

[0172] 5.2 Effect

[0173] In this embodiment, since the second CLBO crystal 52 is a nonlinear optical crystal having a type-2 phase matching condition, it is not necessary to provide the half-wave plate 57 as in the second embodiment. This can suppress the influence of thermal load on the polarization direction.

[0174] 6. Method for manufacturing electronic devices

[0175] Fig. 9 The structure example of the exposure device 100 is schematically shown. The exposure device 100 includes an illumination optical system 104 and a projection optical system 106. The illumination optical system 104 illuminates the mask pattern of the mask (not shown) arranged on the mask stage RT by, for example, the pulsed laser PL incident from the solid laser system 10. The projection optical system 106 projects the pulsed laser PL transmitted through the mask in a reduced size and forms an image on the workpiece (not shown) arranged on the workpiece stage WT. The workpiece is a photosensitive substrate such as a semiconductor wafer coated with a photoresist.

[0176] The exposure device 100 exposes the pulsed laser PL reflecting the mask pattern to the workpiece by synchronously moving the mask stage RT and the workpiece stage WT in parallel. After the mask pattern is transferred to the semiconductor wafer through the above-mentioned exposure process, a semiconductor device can be manufactured through multiple processes. A semiconductor device is an example of an "electronic device" in the present disclosure.

[0177] The above description is not limiting but merely illustrative. Therefore, it is obvious to those skilled in the art that modifications can be made to the various embodiments of the present disclosure without departing from the scope of the appended claims.

[0178] The terms used in this specification and the attached claims as a whole should be interpreted as "non-restrictive" terms. For example, the term "including" or "comprising" should be interpreted as "not limited to what is recorded as including". The term "having" should be interpreted as "not limited to what is recorded as having". In addition, the phrases "one" and "one" recorded in this specification and the attached claims should be interpreted as "at least one" or "one or more". In addition, the term "at least one of A, B and C" should be interpreted as "A", "B", "C", "A+B", "A+C", "B+C" or "A+B+C", and should be interpreted to also include combinations of them with parts other than "A", "B" and "C".

Claims

1. A wavelength conversion system, comprising: a first nonlinear optical crystal into which first light having a first wavelength is incident and which outputs second light having a second wavelength which is a double wave of the first light; a second nonlinear optical crystal for inputting the second light and the third light having a third wavelength, and outputting a fourth light and the third light, wherein the fourth light has a fourth wavelength and is a sum frequency light of the second light and the third light; a third nonlinear optical crystal into which the third light and the fourth light are incident and which outputs fifth light having a fifth wavelength which is sum frequency light of the third light and the fourth light; and a converging optical system that causes the first light to be incident on a first nonlinear optical crystal so that a beam waist position of the second light is arranged within the second nonlinear optical crystal, The first nonlinear optical crystal is arranged within a range of the Rayleigh length of the second light from the beam waist position of the second light. The third nonlinear optical crystal is arranged in a range within a Rayleigh length of the fourth light from a beam waist position of the second light.

2. The wavelength conversion system according to claim 1, wherein: When the numerical aperture of the converging optical system is set to NA1, the second wavelength is set to λ2, and the distance from the beam waist position of the second light to the surface of the first nonlinear optical crystal on which the first light is incident is set to L1, the following formula (1) is satisfied:

3. The wavelength conversion system according to claim 1, wherein: The first nonlinear optical crystal, the second nonlinear optical crystal and the third nonlinear optical crystal have a type-1 phase matching condition, The second light and the third light incident on the second nonlinear optical crystal are linearly polarized lights with parallel polarization directions. The wavelength conversion system includes a polarization direction changing optical system that rotates the polarization direction of the third light incident on the third nonlinear optical crystal by 90°.

4. The wavelength conversion system according to claim 3, wherein: The polarization direction changing optical system includes a half-wave plate that rotates the polarization direction of the third light by 90°.

5. The wavelength conversion system according to claim 3, wherein: The polarization direction changing optical system includes a periscope optical system that rotates the polarization direction of the third light by 90°.

6. The wavelength conversion system according to claim 1, wherein: The first nonlinear optical crystal and the third nonlinear optical crystal respectively have a type-1 phase matching condition, The second nonlinear optical crystal has a type-2 phase matching condition, The second light and the third light incident on the second nonlinear optical crystal are linearly polarized lights, and the polarization directions thereof are perpendicular to each other.

7. The wavelength conversion system according to claim 1, wherein: The first nonlinear optical crystal, the second nonlinear optical crystal and the third nonlinear optical crystal are CLBO crystals.

8. The wavelength conversion system according to claim 1, wherein: The third wavelength is longer than the first wavelength, the first wavelength is longer than the second wavelength, the second wavelength is longer than the fourth wavelength, and the fourth wavelength is longer than the fifth wavelength.

9. A solid-state laser system comprising: Wavelength conversion system; A signal laser system, which outputs a signal laser; an amplification system, which performs pulse amplification on the signal laser based on a pump laser, and outputs the pulse-amplified signal laser as a third light to the wavelength conversion system; and a pump laser device that generates the pump laser and the first light, outputs the pump laser to the amplification system, and outputs the first light to the wavelength conversion system, The wavelength conversion system comprises: a first nonlinear optical crystal into which the first light having a first wavelength is incident and outputs a second light having a second wavelength which is a double wave of the first light; a second nonlinear optical crystal for inputting the second light and the third light having a third wavelength, and outputting a fourth light and the third light, wherein the fourth light has a fourth wavelength and is a sum frequency light of the second light and the third light; a third nonlinear optical crystal into which the third light and the fourth light are incident and which outputs fifth light having a fifth wavelength which is sum frequency light of the third light and the fourth light; and a converging optical system that causes the first light to be incident on a first nonlinear optical crystal so that a beam waist position of the second light is arranged within the second nonlinear optical crystal, The first nonlinear optical crystal is arranged within a range of the Rayleigh length of the second light from the beam waist position of the second light. The third nonlinear optical crystal is arranged in a range within a Rayleigh length of the fourth light from a beam waist position of the second light.

10. A method for manufacturing an electronic device, comprising the following steps: The laser light is generated by a solid-state laser system including a wavelength conversion system, outputting the laser to an exposure device, exposing the photosensitive substrate to the laser in the exposure device to manufacture an electronic device, The wavelength conversion system comprises: a first nonlinear optical crystal into which first light having a first wavelength is incident and which outputs second light having a second wavelength which is a double wave of the first light; a second nonlinear optical crystal for inputting the second light and the third light having a third wavelength, and outputting a fourth light and the third light, wherein the fourth light has a fourth wavelength and is a sum frequency light of the second light and the third light; a third nonlinear optical crystal into which the third light and the fourth light are incident and which outputs fifth light having a fifth wavelength which is sum frequency light of the third light and the fourth light; and a converging optical system that causes the first light to be incident on a first nonlinear optical crystal so that a beam waist position of the second light is arranged within the second nonlinear optical crystal, The first nonlinear optical crystal is arranged within a range of the Rayleigh length of the second light from the beam waist position of the second light. The third nonlinear optical crystal is arranged in a range within a Rayleigh length of the fourth light from a beam waist position of the second light.

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