Optical isolator, ultraviolet laser device, and method of manufacturing electronic device

Abstract

An optical isolator according to an aspect of the present disclosure comprises: a case; a first polarizer that is disposed in the case such that incident light of linearly polarized light of an ultraviolet wavelength is transmitted therethrough; a first Faraday rotator that includes a first Faraday material for rotating the polarization direction of light transmitted through the first polarizer in a first rotation direction and a first magnet for generating a first magnetic field in a first magnetic field generation region in which the first Faraday material is disposed, and that is disposed in the case; and a first position adjustment mechanism that moves the first Faraday material relatively to the case. The cross-sectional shape of the first Faraday material in a cross-section perpendicular to the optical axis of light transmitted through the first Faraday material, and the cross-sectional shape of the first magnetic field generation region have long axes facing in the same direction. The first position adjustment mechanism moves the first Faraday material in a short axis direction perpendicular to the long axes.

Description

[Technical Field]

[0001] The present disclosure relates to optical isolators, ultraviolet laser devices, and methods for manufacturing electronic devices. [Background technology]

[0002] In recent years, semiconductor exposure devices have been required to improve their resolution in response to the miniaturization and high integration of semiconductor integrated circuits. To this end, the wavelength of light emitted from exposure light sources has been shortened. For example, KrF excimer laser devices, which output laser light with a wavelength of approximately 248 nm, and ArF excimer laser devices, which output laser light with a wavelength of approximately 193 nm, are used as gas laser devices for exposure.

[0003] The spectral linewidth of the spontaneously oscillating light from KrF excimer laser devices and ArF excimer laser devices is as wide as 350 to 400 pm. Therefore, if a projection lens is constructed using a material that transmits ultraviolet light, such as KrF and ArF laser light, chromatic aberration may occur. As a result, resolution may decrease. Therefore, it is necessary to narrow the spectral linewidth of the laser light output from the gas laser device to a level where chromatic aberration is negligible. Therefore, a line narrowing module (LNM) containing a line narrowing element (e.g., an etalon or grating) may be installed inside the laser resonator of the gas laser device to narrow the spectral linewidth. Hereinafter, a gas laser device with a narrowed spectral linewidth is referred to as a line narrowing gas laser device. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] European Patent Application Publication No. 1072938 [Patent Document 2] Summary of JP 2007-183419 A

[0005] An optical isolator according to one aspect of the present disclosure comprises a case, a first polarizer disposed within the case so as to transmit linearly polarized incident light of ultraviolet wavelengths, a first Faraday rotator disposed within the case, the first Faraday rotator including a first Faraday material that rotates the polarization direction of the light transmitted through the first polarizer in a first rotation direction and a first magnet that generates a first magnetic field in a first magnetic field generating region in which the first Faraday material is disposed, and a first position adjustment mechanism that moves the first Faraday material relative to the case, wherein the cross-sectional shape of the first Faraday material in a cross section perpendicular to the optical axis of the light transmitted through the first Faraday material and the cross-sectional shape of the first magnetic field generating region have long axes oriented in the same direction, and the first position adjustment mechanism moves the first Faraday material in the short-axis direction perpendicular to the long axis.

[0006] An ultraviolet laser device according to another aspect of the present disclosure includes an oscillation-stage laser that outputs linearly polarized pulsed laser light of an ultraviolet wavelength, an amplifier that amplifies and outputs the pulsed laser light, and an optical isolator that is arranged on an optical path between the oscillation-stage laser and the amplifier, the optical isolator including a case, a first polarizer that is arranged in the case so that incident linearly polarized light of an ultraviolet wavelength passes through, a first Faraday material that rotates the polarization direction of the pulsed laser light that has passed through the first polarizer in a first rotation direction, and a first Faraday material that rotates the polarization direction of the pulsed laser light that has passed through the first polarizer in a first rotation direction. The device comprises a first Faraday rotator arranged in a case and including a first magnet that generates a first magnetic field in a first magnetic field generating region in which a material is arranged, and a first position adjustment mechanism that moves the first Faraday material relative to the case, wherein the cross-sectional shape of the first Faraday material in a cross section perpendicular to the optical axis of light passing through the first Faraday material and the cross-sectional shape of the first magnetic field generating region have long axes in the same direction, and the first position adjustment mechanism moves the first Faraday material in the short axis direction perpendicular to the long axis.

[0007] A manufacturing method for an electronic device according to another aspect of the present disclosure includes an oscillation-stage laser that outputs linearly polarized pulsed laser light of an ultraviolet wavelength, an amplifier that amplifies and outputs the pulsed laser light, and an optical isolator that is arranged on an optical path between the oscillation-stage laser and the amplifier, the optical isolator including a case, a first polarizer that is arranged within the case so that incident linearly polarized light of an ultraviolet wavelength passes through, a first Faraday material that rotates the polarization direction of the pulsed laser light that has passed through the first polarizer in a first rotation direction, and a first magnet that generates a first magnetic field in a first magnetic field generation region in which the first Faraday material is arranged, the cross-sectional shape of the first Faraday material in a cross section perpendicular to the optical axis of light passing through the first Faraday material and the cross-sectional shape of the first magnetic field generating region have long axes oriented in the same direction, and the first position adjustment mechanism moves the first Faraday material in a short axis direction perpendicular to the long axis; generating laser light amplified by an amplifier using an ultraviolet laser device, outputting the amplified laser light to an exposure device, and exposing the laser light onto a photosensitive substrate in the exposure device to manufacture an electronic device. [Brief explanation of the drawings]

[0008] Some embodiments of the present disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which: [Figure 1] FIG. 1 is a side view schematically showing the configuration of an ultraviolet laser device according to a comparative example. [Figure 2] FIG. 2 is a diagram showing a problem with the ultraviolet laser device according to the comparative example. [Figure 3] FIG. 3 shows a schematic configuration of an optical isolator according to a comparative example that suppresses optical feedback. [Figure 4] FIG. 4 shows a schematic configuration of an ultraviolet laser device including an optical isolator. [Figure 5] FIG. 5 is a schematic diagram showing the configuration of the optical isolator according to the first embodiment. [Figure 6] FIG. 6 is a cross-sectional view taken along line 6-6 in FIG. [Figure 7] FIG. 7 is an explanatory diagram showing an example of a shape having a long axis. [Figure 8] FIG. 8 shows a schematic cross-sectional shape of a Faraday rotator taken along a cross section perpendicular to the optical axis. [Figure 9] FIG. 9 shows a specific example of the configuration of the optical isolator according to the first embodiment. [Figure 10] FIG. 10 is a cross-sectional view taken along line 10-10 in FIG. [Figure 11] FIG. 11 shows a schematic configuration of an optical isolator according to the first modification. [Figure 12] FIG. 12 shows a schematic configuration of an optical isolator according to the second modification. [Figure 13] FIG. 13 shows a schematic configuration of an optical isolator according to the third modification. [Figure 14] FIG. 14 is a schematic diagram showing the configuration of an optical isolator according to the second embodiment. [Figure 15] FIG. 15 is a cross-sectional view taken along line 15-15 in FIG. [Figure 16] FIG. 16 shows a schematic configuration example of an exposure apparatus. Embodiment

[0009] -table of contents- 1. Explanation of terms 2. Overview of the ultraviolet laser device according to the comparative example 2.1 Configuration 2.2 Operation 3. Challenges 4. Embodiment 1 4.1 Configuration 4.2 Operation 4.3 Actions and Effects 4.4 Variation 1 4.5 Variation 2 4.6 Variation 3 4.6.1 Configuration 4.6.2 Operation 4.6.3 Actions and Effects 5. Embodiment 2 5.1 Configuration 5.2 Operation 5.3 Actions and Effects 6. Other configuration examples of ultraviolet laser devices 7. Manufacturing methods for electronic devices 8.Other Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The embodiments described below show some examples of the present disclosure and do not limit the content of the present disclosure. Furthermore, not all of the configurations and operations described in each embodiment are necessarily essential as the configurations and operations of the present disclosure. Note that the same components are given the same reference symbols, and redundant explanations will be omitted.

[0010] 1. Explanation of terms The term "polarizer" refers to an optical element that separates light having a specific polarization direction (transmission axis direction) from light having a polarization direction perpendicular to that direction.

[0011] In this specification, unless otherwise specified, the term "parallel" is not limited to strictly parallel, but also includes the concept of approximately parallel, including a range of angle differences that are practically acceptable and do not lose their technical significance, unless otherwise specified, and in this specification, unless otherwise specified, the term "orthogonal" or "perpendicular" is not limited to strictly orthogonal or perpendicular, but also includes the concept of approximately orthogonal or approximately perpendicular ....

[0012] 2. Overview of the ultraviolet laser device according to the comparative example 2.1 Configuration 1 is a side view showing a schematic configuration of an ultraviolet laser device 20 according to a comparative example. The comparative example of the present disclosure is a configuration that the applicant recognizes as being known only by the applicant, and is not a publicly known example that the applicant acknowledges.

[0013] The ultraviolet laser device 20 is an excimer laser device including a master oscillator (MO) 22, which is an oscillation stage laser, an MO beam steering unit 24, and an amplification stage laser, a power oscillator (PO) 26. The MO 22 includes a line narrowing module (LNM) 30, a chamber 32, and an output coupling mirror 34.

[0014] The LNM 30 includes a prism expander 36 for narrowing the spectral linewidth, and a grating 38. The prism expander 36 and grating 38 are arranged in a Littrow configuration in which the angle of incidence and the angle of diffraction match. The output coupling mirror 34 is a partial reflection mirror with a reflectivity of 40% to 60%. The output coupling mirror 34 is arranged so as to form an optical resonator together with the LNM 30.

[0015] The chamber 32 is disposed on the optical path of the optical resonator. The chamber 32 includes a pair of discharge electrodes 40a, 40b and two windows 42, 44 through which the laser light passes. The chamber 32 is filled with a laser gas. The laser gas includes a rare gas, a halogen gas, and a buffer gas. The rare gas may be, for example, argon (Ar) or krypton (Kr) gas. The halogen gas may be, for example, fluorine (F2) gas. The buffer gas may be, for example, neon (Ne) gas. A voltage is applied between the discharge electrodes 40a, 40b by a power supply (not shown). The power supply may be a pulse power module (PPM) including a switch and a charging capacitor.

[0016] The MO beam steering unit 24 includes a high-reflection mirror 50 and a high-reflection mirror 52, and is disposed so that the laser light output from the MO 22 is incident on the PO .

[0017] An MO pulse energy monitor 54 is disposed between high-reflection mirror 50 and high-reflection mirror 52. The MO pulse energy monitor 54 includes a beam splitter (BS) 55 and an optical sensor 56. The BS 55 is disposed on the optical path of the pulsed laser light output from the MO 22, and is disposed so that the reflected light of the BS 55 enters the optical sensor 56.

[0018] The PO 26 is an amplification stage laser including a rear mirror 60, a chamber 62, and an output coupling mirror 64. The rear mirror 60 and the output coupling mirror 64 form an optical resonator, and the chamber 62 is disposed on the optical path of this optical resonator.

[0019] The configuration of the chamber 62 may be similar to that of the chamber 32. The chamber 62 includes a pair of discharge electrodes 70a, 70b and two windows 72, 74. The chamber 62 is filled with a laser gas. The rear mirror 60 may be, for example, a partial reflection mirror with a reflectance of 50% to 90%. The output coupling mirror 64 may be a partial reflection mirror with a reflectance of 10% to 30%.

[0020] 2.2 Operation A high-voltage pulse is applied between discharge electrodes 40a and 40b in chamber 32 from a power supply (not shown). When a discharge occurs between discharge electrodes 40a and 40b in chamber 32, the laser gas is excited, and pulsed laser light with an ultraviolet wavelength of 150 nm to 380 nm is narrowed by an optical resonator formed by output coupling mirror 34 and LNM 30 and output from output coupling mirror 34.

[0021] The energy of the pulsed laser light output from the output coupling mirror 34 is measured by an MO pulse energy monitor 54. The pulsed laser light is also incident on a rear mirror 60 of the PO 26 by the MO beam steering unit 24 as seed light.

[0022] At the timing when the seed light that has passed through the rear mirror 60 enters the chamber 62, a high-voltage pulse is applied between the discharge electrodes 70a and 70b in the chamber 62 from a power supply (not shown). When a discharge occurs between the discharge electrodes 70a and 70b in the chamber 62, the laser gas is excited, and the seed light is amplified by a Fabry-Perot optical resonator formed by the output coupling mirror 64 and the rear mirror 60, and the amplified pulsed laser light is output from the output coupling mirror 64.

[0023] 3. Challenges FIG. 2 illustrates a problem with the ultraviolet laser device 20 according to the comparative example. Among the pulsed laser light output from the MO 22, some light returns from the PO 26 (return light). When the return light from the PO 26 returns to the MO 22, laser performance deteriorates. The "return light" referred to here includes two types: MO return light and PO leakage light. The light emitted from the MO 22 enters the PO 26, but because the rear mirror 60 inside the PO 26 is a partial reflection mirror (reflectivity 50% to 90%), some of the light that enters the rear mirror 60 returns directly to the MO 22 without entering the PO 26. The light that is reflected by the rear mirror 60 and returns to the MO 22 without entering the chamber 62 of the PO 26 is called "MO return light."

[0024] On the other hand, light that enters PO26 from MO22 and passes through rear mirror 60 is resonated and amplified within PO26 and then output. As mentioned above, because rear mirror 60 within PO26 is a partial reflection mirror, some of the light that enters chamber 62 of PO26 and is amplified returns to MO22. Of the light amplified by PO26, the light that passes through rear mirror 60 and returns to MO22 is called "PO-leaving light."

[0025] The feedback light from the PO 26 becomes a thermal load on the LNM 30 and other components, which can cause deterioration in the stability of the linewidth and pulse energy, etc. To suppress the feedback light entering the MO 22, an optical isolator can be placed between the MO 22 and the PO 26.

[0026] Fig. 3 shows a schematic configuration example of an optical isolator 80 according to a comparative example that suppresses returning light. The optical isolator 80 is disposed between the MO 22 and the PO 26. The upper part of Fig. 3 shows the operation of the optical isolator 80 with respect to pulsed laser light (MO injection light: outgoing light) traveling from the MO 22 to the PO 26. The lower part of Fig. 3 shows the operation of the optical isolator 80 with respect to laser light (returning light) traveling from the PO 26 to the MO 22.

[0027] The optical isolator 80 includes a half-wave plate 81, a first polarizer 83, a Faraday rotator 84, and a second polarizer 88 arranged in this order from the MO22 side. The Faraday rotator 84 includes a Faraday material 85 and a magnet 86. The magnet 86 has a hollow structure, and the Faraday material 85 is arranged inside via a holder. The internal space (hollow portion) of the magnet 86 where the Faraday material 85 is arranged is a magnetic field generation region where a magnetic field is generated to be applied to the Faraday material 85. The magnet 86 may be a permanent magnet. Note that in FIG. 3, the right-pointing arrow shown in the Faraday rotator 84 indicates the direction of the magnetic field applied to the Faraday material 85 by the magnet 86. The double-pointing arrow shown in the dashed circle in the figure indicates the direction of the polarization plane of the pulsed laser light when the line of sight is aligned in the direction in which the pulsed laser light travels, i.e., the polarization direction.

[0028] 3, linearly polarized pulsed laser light polarized in a specific direction (here, the horizontal direction is illustrated) is output from MO 22. The polarization direction of the linearly polarized pulsed laser light output from MO 22 is rotated by 45 degrees counterclockwise by half-wave plate 81. First polarizer 83 is arranged such that its transmission axis is parallel to the polarization direction of the pulsed laser light output from half-wave plate 81, and the pulsed laser light output from half-wave plate 81 passes through first polarizer 83.

[0029] The polarization direction of the pulsed laser light that has passed through the first polarizer 83 is rotated 45 degrees clockwise by the Faraday material 85 to which a magnetic field is applied. As a result, the pulsed laser light output from the Faraday rotator 84 becomes horizontally polarized. The second polarizer 88 is arranged so that its transmission axis is parallel to the polarization direction of the pulsed laser light output from the Faraday rotator 84. The pulsed laser light output from the Faraday rotator 84 passes through the second polarizer 88 and then enters the PO26.

[0030] The half-wave plate 81 adjusts the polarization direction of the pulsed laser light from the MO 22 so that the polarization direction of the pulsed laser light output from the MO 22 is the same as the polarization direction of the pulsed laser light incident on the PO 26. As a result, even if the optical isolator 80 is provided, the polarization direction of the pulsed laser light does not change before and after the optical isolator 80.

[0031] Of the returning light, the polarized component having the same polarization direction as the pulsed laser light incident on PO26 passes through the second polarizer 88, and the polarization direction is rotated 45 degrees clockwise by the Faraday material 85 to which a magnetic field is applied. Then, the returning light is reflected by the first polarizer 83, and does not enter MO22.

[0032] Of the returning light, the polarization component having a polarization direction different from that of the pulsed laser light incident on the PO 26 is reflected by the second polarizer 88 and does not return to the MO 22. The second polarizer 88 is arranged to remove the disturbed polarization component when the polarization of the returning light from the PO 26 is disturbed, thereby achieving a higher effect of the optical isolator 80. Therefore, the second polarizer 88 may not be used if there is no disturbance in the polarization of the returning light or if a sufficient extinction ratio can be obtained even with disturbed returning light.

[0033] Here, the ratio of the returning light transmitted through the first polarizer 83 to the returning light incident on the second polarizer 88 is called the extinction ratio.

[0034] Figure 4 shows a schematic configuration of ultraviolet laser device 21 including optical isolator 90. Differences between the configuration shown in Figure 4 and Figures 1 to 3 will be described below. The ultraviolet laser device 21 shown in Figure 4 has an optical isolator 90 disposed between MO beam steering unit 24A and MO beam steering unit 24B in order to suppress return light.

[0035] In the optical isolator 90, a Faraday rotator 91 is arranged instead of the half-wave plate 81 in Fig. 3. This is because the Faraday material that constitutes the Faraday rotator 91 has higher resistance to laser light with ultraviolet wavelengths than the half-wave plate 81. The function of the Faraday rotator 91 is the same as that of the half-wave plate 81.

[0036] The Faraday rotator 91 has a structure similar to that of the Faraday rotator 84, and includes a Faraday material FM and a magnet MG, not shown. In Fig. 4, the downward arrow shown in the Faraday rotator 91 indicates the direction of the magnetic field applied to the Faraday material FM. The direction of the magnetic field applied to the Faraday material FM by the magnet MG of the Faraday rotator 91 is opposite to the direction of the magnetic field applied to the Faraday material 85 of the Faraday rotator 84.

[0037] The optical isolator 90 includes an isolator case 96 in which a Faraday rotator 91 , a first polarizer 83 , a Faraday rotator 84 and a second polarizer 88 are arranged.

[0038] MO beam steering unit 24A includes high-reflection mirror 50 and beam splitter 55. MO beam steering unit 24B includes high-reflection mirror 52. Isolator case 96 is connected to the case of MO beam steering unit 24A via bellows 25A, and is connected to the case of MO beam steering unit 24B via bellows 25B.

[0039] The optical isolator 90 needs to be arranged so that the pulsed laser light passes through the Faraday material FM, the first polarizer 83, the Faraday material 85, and the second polarizer 88. On the other hand, the optical axis of the pulsed laser light traveling from MO 22 to PO 26 differs depending on the device. For this reason, the optical isolator 90 is provided with a Faraday material FM having a size sufficient relative to the cross section (beam cross section) of the pulsed laser light, the first polarizer 83, the Faraday material 85, and the second polarizer 88.

[0040] However, as the Faraday material FM and the Faraday material 85 become larger, the magnets MG and 86 that apply a uniform magnetic field also become larger. Because the magnets MG and 86 are heavy, the optical isolator 90 in which the two magnets MG and 86 are arranged becomes heavy and difficult to maintain.

[0041] This problem is not limited to the optical isolator 90 illustrated in FIG. 4, but is also the same for the optical isolator 80 using a half-wave plate 81 as shown in FIG. 3; as the Faraday material 85 becomes larger, the magnet 86 also becomes larger, which makes maintenance difficult.

[0042] 4. Embodiment 1 4.1 Configuration FIG. 5 schematically shows the configuration of an optical isolator 110 according to the first embodiment. FIG. 6 is a cross-sectional view taken along line 6-6 in FIG. 5. Differences between the configurations shown in FIGS. 5 and 6 and the optical isolator 90 shown in FIG. 4 will be described below. In the following description, the terms "cross section" and "cross-sectional shape" refer to a cross section perpendicular to the optical axis of the pulsed laser light PL as in FIG. 6, or the shape of that cross section, unless otherwise specified. In FIGS. 5 and 6, the traveling direction of the pulsed laser light PL is parallel to the V-axis direction (V direction), and the cross section shown in FIG. 6 is an HZ plane parallel to the H-axis and Z-axis.

[0043] 4, the optical isolator 110 includes a Faraday rotator 120 and a Faraday rotator 122. The Faraday rotator 120 is disposed closer to the MO22 than the first polarizer 83, that is, on the incident side of the first polarizer 83 on the optical path of the pulsed laser light PL output from the MO22 toward the PO26. The Faraday rotator 120 includes a Faraday material 130 and a magnet 140.

[0044] The magnet 140 of the Faraday rotator 120 can be made smaller if the cross-sectional shape of the magnetic field generation region 142 in which the Faraday material 130 is placed is smaller. Since the cross-sectional shape of the pulsed laser light PL output from the MO 22 is a shape having a major axis (e.g., a rectangle), it is more effective in making the magnet 140 smaller in the cross-sectional shape of the magnetic field generation region 142 by making the length of the minor axis perpendicular to the major axis shorter than the major axis.

[0045] Therefore, in the optical isolator 110, the cross-sectional shape of the Faraday material 130 is made to have its major axis oriented in the same direction as the cross-sectional shape of the pulsed laser light PL, and the minor axis is made as short as possible. In addition, to match this Faraday material 130, the cross-sectional shape of the magnetic field generating region 142 of the magnet 140 is made to have its major axis oriented in the same direction as the Faraday material 130.

[0046] To deal with cases in which the optical axis of the pulsed laser light PL deviates from the design value, the optical isolator 110 is provided with a position adjustment mechanism that adjusts the position by moving the Faraday material 130 in a direction parallel to the minor axis (minor axis direction). A configuration example of the position adjustment mechanism will be described later with reference to FIGS. 8 and 9. The position adjustment mechanism is a mechanism that moves the Faraday rotator 120 relative to the isolator case 96. The double-headed arrow parallel to the Z direction in FIGS. 5 and 6 indicates the direction in which the Faraday rotator 120 is moved by the position adjustment mechanism.

[0047] The position adjustment mechanism may be configured to move the first polarizer 83 together with the movement of the Faraday rotator 120. That is, the Faraday material 130 and the first polarizer 83 may be integrally formed, and the Faraday material 130 and the first polarizer 83 may be moved integrally by the position adjustment mechanism.

[0048] Furthermore, the optical isolator 110 may include a rotation mechanism that rotates the Faraday material 130 about an axis perpendicular to the optical axis of the pulsed laser light PL and the minor axis direction of the Faraday material 130. A configuration example of the rotation mechanism will be described later with reference to FIGS.

[0049] FIG. 7 shows an example of a shape having a major axis. A shape having a major axis refers to a longitudinal shape having a major axis and a minor axis, and refers to a shape in which the length in a first direction, which is the major axis direction, is longer than the length in a second direction, which is the minor axis direction perpendicular to the first direction. Shapes having a major axis include, for example, an ellipse and a rectangle. As shown in the left diagram of FIG. 7, an ellipse has a major axis and a minor axis. As shown in the right diagram of FIG. 7, in the case of a rectangle, the long side is defined as the major axis and the short side is defined as the minor axis. In the first embodiment, an example will be described in which the cross-sectional shape (beam cross section) of the pulsed laser light PL is rectangular, with the major axis oriented in the H direction and the minor axis oriented in the Z direction. Note that shapes having a major axis include a shape obtained by connecting two circles of equal radii with a common circumtangent (an ellipse) and a shape with rounded corners of a rectangle (a rounded rectangle).

[0050] 8 shows a schematic cross-sectional view of the Faraday rotator 120. The Faraday material 130 is held by a Faraday material holder 132 and placed in a magnetic field generating region 142 of a magnet 140. The direction of the magnetic field penetrating the Faraday material 130 is parallel to the direction of light propagation. The direction of rotation of the polarization plane (polarization direction) by the Faraday rotator 120 depends on the sign of the Verdet constant and the direction of the applied magnetic field.

[0051] The cross-sectional shape of the Faraday material 130 has a major axis oriented in the same direction as the cross-sectional shape of the pulsed laser light PL and is larger than the cross-sectional shape of the pulsed laser light PL. The cross-sectional shape of the Faraday material 130 illustrated in Fig. 8 is a rectangle with the major axis oriented in the H direction, and the length LFMz of the minor axis of the Faraday material 130 is longer than the length LPLz of the minor axis of the cross-sectional shape of the pulsed laser light PL, and the length LFMh of the major axis of the Faraday material 130 is longer than the length LPLh of the major axis of the cross-sectional shape of the pulsed laser light PL.

[0052] The difference (LFMz-LPLz) between the minor axis length LFMz of the Faraday material 130 and the minor axis length LPLz of the pulsed laser light PL may be, for example, about 2 mm to 4 mm. Furthermore, the difference (LFMh-LPLh) between the major axis length LFMh of the Faraday material 130 and the major axis length LPLh of the pulsed laser light PL may be, for example, about 3 mm to 5 mm. Because the Faraday material 130 is movable in the minor axis direction, the difference in the minor axis length (LFMz-LPLz) may be smaller than the difference in the major axis length (LFMz-LPLz).

[0053] The cross-sectional shape of the magnetic field generation region 142 in which the Faraday material 130 is disposed has a shape with its major axis oriented in the same direction as the cross-sectional shape of the Faraday material 130. The cross-sectional shape of the magnetic field generation region 142 illustrated in FIG. 8 is a rectangle with its major axis oriented in the H direction. From the perspective of miniaturizing the magnet 140, it is desirable that the length LMGz of the minor axis of the magnetic field generation region 142 be equal to or greater than the length LFMz of the minor axis of the Faraday material 130 and be as short as possible. For example, the difference between LMGz and LFMz (LMGz-LFMz) is desirably 2 mm or less, and more preferably 1 mm or less.

[0054] The length LMGh of the major axis of the magnetic field generation region 142 is equal to or greater than the length LFMh of the major axis of the Faraday material 130, and is actually equal to or greater than the length in the H direction of the Faraday material holder 132. The difference between the length LMGh of the major axis of the magnetic field generation region 142 and the length LFMh of the major axis of the Faraday material 130 (LMGh-LFMh) may be greater than the difference between LMGz and LFMz in the minor axis directions (LMGz-LFMz).

[0055] To give a specific example of dimensions, for example, if the minor axis length LPLz of the cross section of the pulsed laser light PL is 2 mm and the major axis length LPLh is 12 mm, the minor axis length LFMz of the Faraday material 130 is preferably 4 mm to 6 mm and the major axis length LFMh is preferably 15 mm to 17 mm. In this case, the minor axis length LMGz of the magnetic field generation region 142 is preferably 4 mm to 7 mm and the major axis length LMGh is preferably 17 mm or more.

[0056] The Faraday rotator 122 may have a configuration similar to that of the Faraday rotator 120. The Faraday material 130, the Faraday material holder 132, and the magnet 140 shown in FIG. 8 may be understood to be replaced with the Faraday material, the Faraday material holder, the magnet, and the magnetic field generating region of the Faraday rotator 122.

[0057] 9 and 10 show specific configuration examples of the optical isolator 110. Fig. 10 is a cross-sectional view taken along line 10-10 in Fig. 9.

[0058] The Faraday material 130 of the Faraday rotator 120, the Faraday material holder 132, the magnet 140, the polarizer holder 146, and the first polarizer 83 are integrally configured to form a magnet block MGB1. Of the components constituting the magnet block MGB1, all except the magnet 140 are made of non-magnetic materials. The non-magnetic material may be, for example, copper-based, aluminum-based, or austenitic stainless steel. The first polarizer 83 is integrally configured with the Faraday rotator 120 while being held by the polarizer holder 146. The Faraday material 130 is placed in the magnetic field generation region 142 of the magnet 140 while being held by the Faraday material holder 132.

[0059] Similarly, the Faraday material 150 of the Faraday rotator 122, the Faraday material holder 152, the magnet 160, the polarizer holder 166, and the second polarizer 88 are integrally configured to form a magnet block MGB2. Of the members constituting the magnet block MGB2, all except the magnet 160 are made of non-magnetic materials. The second polarizer 88 is configured integrally with the Faraday rotator 122 while being held by the polarizer holder 166. The Faraday material 150 is placed in the magnetic field generating region 162 of the magnet 160 while being held by the Faraday material holder 152.

[0060] Magnet blocks MGB1 and MGB2 are disposed in a sealable isolator case 96. The opening of the isolator case 96 in the H direction is covered by an isolator lid 98. The isolator case 96 and the isolator lid 98 are sealed with an O-ring 97. The isolator lid 98 has through holes 99a and 99b. A slide plate 170 is inserted into the through hole 99a, and a slide plate 180 is inserted into the through hole 99b. The through holes 99a and 99b are elongated in the Z direction, and the slide plate 170 is fixed to the isolator lid 98 in a manner that allows it to slide in the Z direction along the through hole 99a. For example, through holes 171 are formed in the four corners of the slide plate 170, through which fixing screws (not shown) can be inserted to fix the slide plate 170 to the isolator lid 98. The through holes 171 may also be oval in shape elongated in the Z direction. Furthermore, the isolator lid 98 is provided with a Z-direction adjustment screw 172 that slides the slide plate 170 in the Z direction.

[0061] 10, the magnet block MGB1 is supported on the slide plate 170 via a shaft 174. That is, the magnet block MGB1 is fixed to one end of the shaft 174, and the shaft 174 is inserted into a through-hole 175 of the slide plate 170. The shaft 174 is cylindrical and rotatable about an axis of rotation parallel to the H direction. A handle 176 is fixed to the other end of the shaft 174, and the handle 176 rotates about the axis of rotation of the shaft 174 and is fixed to the slide plate 170.

[0062] The shaft 174 and the slide plate 170 are sealed with an O-ring 178 , and the slide plate 170 and the isolator lid 98 are sealed with an O-ring 179 .

[0063] The magnet block MGB2, slide plate 180, shaft 184, through-hole 185, and handle 186 are configured in the same manner as the magnet block MGB1, etc. The slide plate 180 is fixed to the isolator lid 98 in a manner that allows it to slide in the Z direction along the through-hole 99b. The through-hole 181 of the slide plate 180 may be an elongated hole that is long in the Z direction, and the isolator lid 98 is provided with a Z-direction adjustment screw 182 that slides the slide plate 180 in the Z direction.

[0064] The shaft 184 and the slide plate 180 are sealed with an O-ring 188 , and the slide plate 180 and the isolator lid 98 are sealed with an O-ring 189 .

[0065] Faraday material 130 and Faraday material 150 may be, for example, calcium fluoride (CaF2) crystals.

[0066] The isolator case 96 is provided with an inlet 190 and an inlet port 191 for introducing a purge gas, and an outlet 194 and an exhaust port 195 for exhausting the purge gas.

[0067] 4.2 Operation The Faraday material 130 , the first polarizer 83 , the Faraday material 150 , and the second polarizer 88 are disposed in the designed positions within the isolator case 96 of the optical isolator 110 .

[0068] The optical isolator 110 is placed on a frame (not shown) of the ultraviolet laser device 21 by positioning it with a positioning pin (not shown).

[0069] An example of an adjustment procedure after the optical isolator 110 is placed in the ultraviolet laser device 21 will be described below.

[0070] [Step 1] An optical sensor PS (not shown), such as a power meter, is attached to the location of the bellows 25B.

[0071] [Step 2] Laser oscillation is generated from MO22, and the Z-direction adjustment screw 172 is turned to move the magnet block MGB1, the shaft 174, the slide plate 170, and the handle 176 in the Z direction, and they are fixed at the position where the power at the optical sensor PS is maximum.

[0072] [Step 3] In addition to adjusting the position in the Z direction in step 2, the handle 176 may be rotated about an axis parallel to the H axis and fixed at the position where the power at the optical sensor PS is maximized.

[0073] [Step 4] Make the same adjustment for magnet block MGB2.

[0074] [Step 5] After that, remove the optical sensor PS and install the bellows 25B.

[0075] [Step 6] Purge gas may be introduced into the isolator case 96 from the inlet 191 through the inlet 190, and then exhausted from the exhaust port 195 through the exhaust port 194. Alternatively, the inlet 190, the inlet 191, the exhaust port 194, and the exhaust port 195 may not be provided, and the purge gas may be introduced through the bellows 25A and exhausted from the bellows 25B. The purge gas may also flow in the opposite direction. The purge gas may be, for example, nitrogen. Nitrogen is an example of a "gas" in this disclosure. The bellows 25A and 25B may be examples of an "inlet" and an "exhaust port" in this disclosure.

[0076] The function of the Faraday rotator 120 is the same as that of the half-wave plate 81 in FIG. 3 . The function of the Faraday rotator 122 is the same as that of the Faraday rotator 84 in FIG. 3 . The isolator case 96 and the isolator lid 98 are examples of a "case" in the present disclosure. The pulsed laser light PL that passes through the Faraday rotator 122 and enters the first polarizer 83 is an example of an "incident light" in the present disclosure. The Faraday rotator 122 is an example of a "first Faraday rotator" in the present disclosure, and the Faraday material 150, the magnet 160, and the magnetic field generation region 162 are examples of a "first Faraday material," a "first magnet," and a "first magnetic field generation region" in the present disclosure. The magnetic field generated in the magnetic field generation region 162 by the magnet 160 is an example of a "first magnetic field" in the present disclosure.

[0077] The position adjustment mechanism including the slide plate 180 and Z-direction adjustment screw 182 for moving the magnet block MGB2 in the Z direction is an example of a "first position adjustment mechanism" in the present disclosure. The slide plate 180 is an example of a "first slide plate" in the present disclosure, and the Z-direction adjustment screw 182 is an example of a "first adjustment screw" in the present disclosure. The rotation mechanism including the shaft 184 and handle 186 for rotating the magnet block MGB2 about a rotation axis parallel to the H direction is an example of a "first rotation mechanism" in the present disclosure. The shaft 184 is an example of a "first axis" in the present disclosure. The rotation direction (clockwise in FIG. 3 ) in which the polarization direction of the pulsed laser beam PL transmitted through the first polarizer 83 is rotated by 45 degrees as a result of the pulsed laser beam PL passing through the Faraday rotator 122 is an example of a "first rotation direction" in the present disclosure.

[0078] The Faraday rotator 120 is an example of a "second Faraday rotator" in the present disclosure, and the Faraday material 130, the magnet 140, and the magnetic field generation region 142 are examples of a "second Faraday material," a "second magnet," and a "second magnetic field generation region" in the present disclosure. The magnetic field generated in the magnetic field generation region 142 by the magnet 140 is an example of a "second magnetic field" in the present disclosure.

[0079] The position adjustment mechanism including the slide plate 170 and Z-direction adjustment screw 172 for moving the magnet block MGB1 in the Z direction is an example of a "second position adjustment mechanism" in the present disclosure. The slide plate 170 is an example of a "second slide plate" in the present disclosure, and the Z-direction adjustment screw 172 is an example of a "second adjustment screw" in the present disclosure. The rotation mechanism including the shaft 174 and handle 176 for rotating the magnet block MGB1 about a rotation axis parallel to the H direction is an example of a "second rotation mechanism" in the present disclosure. The shaft 174 is an example of a "second shaft" in the present disclosure. The rotation direction (counterclockwise in FIG. 3 ) in which the polarization direction of the pulsed laser beam PL output from the MO 22 is rotated by 45 degrees as the pulsed laser beam PL passes through the Faraday rotator 120 is an example of a "second rotation direction" in the present disclosure.

[0080] 4.3 Actions and Effects According to the optical isolator 110 of the first embodiment, the cross-sectional shape of the Faraday materials 130, 150 is made to have a long axis and a short axis that is as short as possible, and accordingly, the cross-sectional shape of the magnetic field generating regions 142, 162 of the magnets 140, 160 is made to have a long axis in the same direction, so that the magnets 140, 160 can be efficiently miniaturized.

[0081] Furthermore, according to the optical isolator 110 of the first embodiment, if the optical axis of the pulsed laser light PL traveling from the MO 22 to the PO 26 deviates from the design value, the position adjustment mechanism including the Z-direction adjustment screws 172, 182 can be used to adjust the pulsed laser light PL so that it passes through the Faraday materials 130, 150.

[0082] By miniaturizing the magnets 140 and 160, the weight of the optical isolator 110 is reduced accordingly, improving maintainability.

[0083] 4.4 Variation 1 Fig. 11 shows a schematic configuration of an optical isolator 111 according to Modification 1. The optical isolator 111 shown in Fig. 11 may be used instead of the optical isolator 110 described with reference to Figs. 5 to 10. Differences between the configuration shown in Fig. 11 and Fig. 9 will be described below.

[0084] If there is no need to adjust the polarization direction of the pulsed laser light PL output from the MO 22 to be the same as the polarization direction of the pulsed laser light PL incident on the PO 26, the Faraday rotator 120 does not need to be provided, and an optical isolator 111 as shown in Fig. 11 can be used. The optical isolator 111 does not include the Faraday rotator 120, nor does it include a position adjustment mechanism such as a slide plate 170 and a Z-direction adjustment screw 172 for moving the Faraday rotator 120.

[0085] In the optical isolator 111, the first polarizer 83, the polarizer holder 147, the Faraday material 150 of the Faraday rotator 122, the Faraday material holder 152, the magnet 160, the polarizer holder 166, and the second polarizer 88 are integrally formed into a magnet block MGB2.

[0086] The first polarizer 83 is integrally formed with the Faraday rotator 122 while being held by a polarizer holder 147. The other configurations may be the same as those of the optical isolator 110 according to the first embodiment.

[0087] 4.5 Variation 2 Fig. 12 shows a schematic configuration of an optical isolator 112 according to Modification 2. When there is no disturbance in the polarization of the returning light or when a sufficient extinction ratio can be obtained even with returning light with disturbed polarization, the second polarizer 88 does not need to be disposed, and an optical isolator 112 as shown in Fig. 12 may be used instead of the optical isolator 111 of Fig. 11. The differences between the configuration shown in Fig. 12 and Fig. 11 will be described below.

[0088] The optical isolator 112 does not include the second polarizer 88 and the polarizer holder 166. The other configurations are the same as those of the optical isolator 111 shown in FIG.

[0089] 4.6 Variation 3 4.6.1 Configuration Fig. 13 shows a schematic configuration of an optical isolator 113 according to Modification 3. The optical isolator 113 shown in Fig. 13 may be used instead of the optical isolator 110 described with reference to Figs. 5 to 10. The differences between the configuration shown in Fig. 13 and Fig. 5 will be described below.

[0090] In the optical isolator 113, an optical axis shift cancellation element 201 is arranged on the optical path between the first polarizer 83 and the Faraday rotator 122, and an optical axis shift cancellation element 202 is arranged on the optical path between the second polarizer 88 and the bellows 25B. The optical axis shift cancellation element 202 is arranged on the side closer to PO26 than the second polarizer 88, that is, on the exit side of the second polarizer 88 on the optical path of the pulsed laser beam PL that is output from the Faraday rotator 122 and travels toward the second polarizer 88.

[0091] The optical axis shift cancellation elements 201 and 202 may be, for example, parallel plates made of calcium fluoride. The optical axis shift cancellation element 201 is an example of a "first optical axis shift cancellation element" in the present disclosure. The optical axis shift cancellation element 202 is an example of a "second optical axis shift cancellation element" in the present disclosure.

[0092] The optical axis shift cancellation element 201 may be disposed in the polarizer holder 146 of the magnet block MGB1. The optical axis shift cancellation element 202 may be disposed in the polarizer holder 166 of the magnet block MGB2.

[0093] 4.6.2 Operation The optical axis of the pulsed laser beam PL output from the MO 22 is offset before and after passing through the first polarizer 83. By providing the optical axis shift cancellation element 201, this offset is cancelled.

[0094] Similarly, the optical axis of the pulsed laser light PL output from the MO 22 is offset before and after passing through the second polarizer 88. This offset is canceled by providing the optical axis shift cancellation element 202. Note that in a configuration in which the second polarizer 88 is not provided, the optical axis shift cancellation element 202 is also unnecessary.

[0095] 4.6.3 Actions and Effects According to the optical isolator 113 of the third modification, by disposing the optical axis shift cancellation element 201, the optical axis of the pulsed laser light PL passing through the Faraday material 130 and the optical axis of the pulsed laser light PL passing through the Faraday material 150 become the same.

[0096] Furthermore, by providing the optical axis shift cancellation element 202, the optical axis of the pulsed laser light PL passing through the Faraday material 130 and the optical axis of the pulsed laser light PL output from the optical isolator 113 toward the PO 26 become the same. Other functions and effects are the same as those of the first embodiment.

[0097] 5. Embodiment 2 5.1 Configuration Fig. 14 schematically shows the configuration of an optical isolator 114 according to embodiment 2. Fig. 15 is a cross-sectional view taken along line 15-15 in Fig. 14. The optical isolator 114 in Fig. 14 may be used instead of the optical isolator 110 described in Figs. 5 to 10. The differences between the configurations shown in Figs. 14 and 15 and those in Figs. 9 and 10 will be described below.

[0098] In optical isolator 114, instead of slide plates 170 and 180 in optical isolator 110, slide plate 210 is arranged that serves the functions of slide plates 170 and 180. Slide plate 210 has through-hole 211 instead of through-holes 171 and 181. The other configurations may be the same as those in the first embodiment.

[0099] 5.2 Operation The Z-direction adjustment of slide plate 210 is performed using Z-direction adjustment screw 172 and Z-direction adjustment screw 182. Note that the Z-direction adjustment of slide plate 210 may be performed using only one of Z-direction adjustment screw 172 and Z-direction adjustment screw 182. Other operations are the same as those in the first embodiment.

[0100] Slide plate 210 is an example of the "third slide plate" in this disclosure.

[0101] 5.3 Actions and Effects According to the optical isolator 114 of the second embodiment, in addition to the effects and advantages of the first embodiment, adjustment can be performed without disrupting the relative positional relationship between the two magnet blocks MGB1 and MGB2, thereby shortening the adjustment time.

[0102] 6. Other configuration examples of ultraviolet laser devices The oscillation stage laser is not limited to a narrow-band gas laser such as the MO22 shown in Fig. 4, but may also be an ultraviolet solid-state laser that outputs pulsed laser light with an ultraviolet wavelength. For example, the oscillation stage laser may be a solid-state laser that oscillates at a wavelength of approximately 193.4 nm, or an ultraviolet solid-state laser that outputs fourth harmonic light of a titanium sapphire laser (wavelength approximately 774 nm).

[0103] The amplification-stage laser is not limited to a configuration having a Fabry-Perot resonator such as PO26 shown in Figure 4, but may also have a configuration having a ring resonator. Alternatively, the amplification-stage laser is not limited to a configuration having an optical resonator, but may also be a simple amplifier. For example, the amplification-stage laser may be a multi-pass amplifier such as a three-pass amplifier that amplifies seed light by reflecting it off a cylindrical mirror and passing it through a discharge space three times.

[0104] 7. Manufacturing methods for electronic devices 16 shows a schematic configuration example of an exposure apparatus 300. The exposure apparatus 300 includes an illumination optical system 304 and a projection optical system 306. The ultraviolet laser device 21 generates laser light and outputs it to the exposure apparatus 300. The illumination optical system 304 uses the laser light incident from the ultraviolet laser device 21 to illuminate a reticle pattern on a reticle (not shown) placed on a reticle stage RT. The projection optical system 306 reduces and projects the laser light that has passed through the reticle, forming an image on a workpiece (not shown) placed on a workpiece table WT. The workpiece is a photosensitive substrate such as a semiconductor wafer coated with photoresist.

[0105] The exposure apparatus 300 exposes the workpiece with laser light reflecting the reticle pattern by synchronously translating the reticle stage RT and the workpiece table WT. After the reticle pattern is transferred to the semiconductor wafer through the exposure process described above, a semiconductor device can be manufactured through multiple processes. A semiconductor device is an example of an "electronic device" in this disclosure.

[0106] 8.Other The above description is intended to be illustrative rather than limiting. Thus, it will be apparent to one skilled in the art that modifications can be made to the disclosed embodiments without departing from the scope of the claims. It will also be apparent to one skilled in the art that the disclosed embodiments can be used in combination.

[0107] Terms used throughout this specification and claims should be construed as "open ended" unless expressly stated otherwise. For example, terms such as "comprise," "have," "comprise," and "equip" should be construed as meaning "without excluding the presence of elements other than those listed." In addition, the modifier "a" should be construed as meaning "at least one" or "one or more." In addition, the term "at least one of A, B, and C" should be construed as "A," "B," "C," "A+B," "A+C," "B+C," or "A+B+C." Furthermore, it should be construed as including combinations of these with elements other than "A," "B," and "C."

Claims

1. Case and a first polarizer disposed within the case so as to transmit linearly polarized incident light of ultraviolet wavelengths; a first Faraday rotator disposed within the case, the first Faraday rotator including a first Faraday material that rotates the polarization direction of light transmitted through the first polarizer in a first rotation direction and a first magnet that generates a first magnetic field in a first magnetic field generating region in which the first Faraday material is disposed; a first position adjustment mechanism that moves the first Faraday material relative to the case; a cross-sectional shape of the first Faraday material in a cross section perpendicular to an optical axis of light transmitted through the first Faraday material and a cross-sectional shape of the first magnetic field generation region have major axes in the same direction, the first position adjustment mechanism moves the first Faraday material in a minor axis direction perpendicular to the major axis; Optical isolator.

2. 2. The optical isolator of claim 1, a first rotation mechanism configured to rotate the first Faraday material around an axis perpendicular to an optical axis of the incident light and a minor axis direction of the first Faraday material; Optical isolator.

3. 2. The optical isolator of claim 1, a second Faraday rotator, which is disposed on the incident light side of the first polarizer in the case and which includes a second Faraday material that rotates the polarization direction of the incident light that is incident on the first polarizer in a second rotation direction that is opposite to the first rotation direction, and a second magnet that generates a second magnetic field in a second magnetic field generating region in which the second Faraday material is disposed; a second position adjustment mechanism that moves the second Faraday material relative to the case, a cross-sectional shape of the second Faraday material in a cross section perpendicular to an optical axis of light transmitted through the second Faraday material and a cross-sectional shape of the second magnetic field generation region have major axes in the same direction, the second position adjustment mechanism moves the second Faraday material in a minor axis direction perpendicular to a major axis of a cross-sectional shape of the second Faraday material; Optical isolator.

4. 4. The optical isolator according to claim 3, a second rotation mechanism that rotates the second Faraday material around an axis perpendicular to the optical axis of the incident light and the minor axis direction of the cross-sectional shape of the second Faraday material; Optical isolator.

5. 4. The optical isolator according to claim 3, the second Faraday rotator and the first polarizer are integral with each other; Optical isolator.

6. 2. The optical isolator of claim 1, a second polarizer disposed within the case so as to transmit the light output from the first Faraday rotator; Optical isolator.

7. 7. The optical isolator according to claim 6, the first Faraday rotator and the second polarizer are integral with each other; Optical isolator.

8. 2. The optical isolator of claim 1, the first Faraday rotator and the first polarizer are integral with each other; Optical isolator.

9. 2. The optical isolator of claim 1, the case is sealable; The case has a gas inlet and an exhaust port. Optical isolator.

10. 2. The optical isolator of claim 1, a first optical axis shift cancellation element disposed between the first polarizer and the first Faraday rotator in the case, the first optical axis shift cancellation element canceling an offset of the optical axis caused by the first polarizer; Optical isolator.

11. 7. The optical isolator according to claim 6, a second optical axis shift cancellation element for canceling an offset of an optical axis caused by the second polarizer, the second optical axis shift cancellation element being provided on an output side of the second polarizer on an optical path of light traveling from the first Faraday rotator to the second polarizer in the case; Optical isolator.

12. 2. The optical isolator of claim 1, the first faradic material is calcium fluoride; Optical isolator.

13. 4. The optical isolator according to claim 3, the second Faraday material is calcium fluoride; Optical isolator.

14. 2. The optical isolator of claim 1, The first position adjustment mechanism includes: a first adjusting screw fixed to the case; a first slide plate that moves in the minor axis direction by the first adjustment screw; Including, the first Faraday rotator is supported by the first slide plate; Optical isolator.

15. 4. The optical isolator according to claim 3, The second position adjustment mechanism includes: a second adjusting screw fixed to the case; a second slide plate that moves in the minor axis direction by the second adjustment screw; Including, the second Faraday rotator is supported by the second slide plate; Optical isolator.

16. 2. The optical isolator of claim 1, a second Faraday rotator including: a second Faraday material disposed on an incident side of the first polarizer in the case, the second Faraday rotator rotating the polarization direction of the incident light incident on the first polarizer in a second rotation direction opposite to the first rotation direction; and a second magnet generating a second magnetic field in a second magnetic field generating region in which the second Faraday material is disposed; a cross-sectional shape of the second Faraday material in a cross section perpendicular to an optical axis of light transmitted through the second Faraday material and a cross-sectional shape of the second magnetic field generation region have major axes in the same direction, the first position adjustment mechanism moves the second Faraday material together with the first Faraday material in a minor axis direction perpendicular to a major axis of a cross-sectional shape of the second Faraday material; Optical isolator.

17. 17. The optical isolator of claim 16, The first position adjustment mechanism includes: a first adjusting screw fixed to the case; a third slide plate that moves in the minor axis direction by the first adjustment screw; Including, the first Faraday rotator and the second Faraday rotator are supported by the third slide plate; When the third slide plate moves, the second Faraday material moves together with the first Faraday material relative to the case. Optical isolator.

18. An ultraviolet laser device, an oscillation stage laser that outputs linearly polarized pulsed laser light of an ultraviolet wavelength; an amplifier that amplifies and outputs the pulsed laser light; an optical isolator disposed on an optical path between the oscillation stage laser and the amplifier, The optical isolator comprises: Case and a first polarizer disposed within the case so as to transmit linearly polarized incident light of ultraviolet wavelengths; a first Faraday rotator disposed in the case, the first Faraday rotator including a first Faraday material that rotates the polarization direction of the pulsed laser light that has passed through the first polarizer in a first rotation direction and a first magnet that generates a first magnetic field in a first magnetic field generation region in which the first Faraday material is disposed; a first position adjustment mechanism that moves the first Faraday material relative to the case; a cross-sectional shape of the first Faraday material in a cross section perpendicular to an optical axis of light transmitted through the first Faraday material and a cross-sectional shape of the first magnetic field generation region have major axes in the same direction, the first position adjustment mechanism moves the first Faraday material in a minor axis direction perpendicular to the major axis; Ultraviolet laser device.

19. A method for manufacturing an electronic device, comprising: an oscillation stage laser that outputs linearly polarized pulsed laser light of an ultraviolet wavelength; an amplifier that amplifies and outputs the pulsed laser light; an optical isolator disposed on an optical path between the oscillation stage laser and the amplifier, The optical isolator comprises: Case and a first polarizer disposed within the case so as to transmit linearly polarized incident light of ultraviolet wavelengths; a first Faraday rotator disposed in the case, the first Faraday rotator including a first Faraday material that rotates the polarization direction of the pulsed laser light that has passed through the first polarizer in a first rotation direction and a first magnet that generates a first magnetic field in a first magnetic field generation region in which the first Faraday material is disposed; a first position adjustment mechanism that moves the first Faraday material relative to the case; a cross-sectional shape of the first Faraday material in a cross section perpendicular to an optical axis of light transmitted through the first Faraday material and a cross-sectional shape of the first magnetic field generation region have major axes in the same direction, the first position adjustment mechanism moves the first Faraday material in a minor axis direction perpendicular to the major axis; and the laser light amplified by the amplifier is generated using an ultraviolet laser device; outputting the amplified laser light to an exposure device; exposing the laser light onto a photosensitive substrate in the exposure apparatus to manufacture an electronic device. A method for manufacturing an electronic device, comprising:

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