Extreme ultraviolet light generation apparatus and method of manufacturing electronic device

Abstract

To solve the problem that conversion efficiency from energy of laser light to energy of EUV light is low and further improvement is required.SOLUTION: The extreme ultraviolet light generation apparatus includes a chamber, a target supply unit configured to supply a target into the chamber, a first laser apparatus configured to irradiate the target with a first pre-pulse laser beam having a wavelength of 1 μm to generate a diffused target convex in a traveling direction of the first pre-pulse laser beam, a second laser apparatus configured to irradiate the diffused target with a second pre-pulse laser beam having a wavelength of 1 μm to generate a low-density diffused target, and a third laser apparatus configured to irradiate the low-density diffused target with a main pulse laser beam having a wavelength of 1 μm to generate extreme ultraviolet light.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to an extreme ultraviolet light generating apparatus and a method for manufacturing an electronic device. [Background technology]

[0002] In recent years, with the miniaturization of semiconductor processes, the miniaturization of transfer patterns in optical lithography for semiconductor processes has progressed rapidly. In the next generation, fine processing of 10 nm or less will be required. For this reason, there is a demand for the development of semiconductor exposure equipment that combines a device for generating extreme ultraviolet (EUV) light with a wavelength of approximately 13 nm and a reduced projection reflective optical system.

[0003] As an EUV light generation device, development of an LPP (Laser Produced Plasma) type device that uses plasma generated by irradiating a target material with laser light is progressing. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent Application Publication No. 2021 / 0026254 [Patent Document 2] Patent Publication No. 2009-105006 [Patent Document 3] US Patent Application Publication No. 2014 / 0264087 [Patent Document 4] US Patent Application Publication No. 2012 / 0243566 [Patent Document 5] Summary of the specification of U.S. Patent No. 8,791,440

[0005] An extreme ultraviolet light generation apparatus according to one aspect of the present disclosure includes a chamber, a target supply unit that supplies a target into the chamber, a first laser device that generates a diffused target that is convex in a traveling direction of the first pre-pulse laser beam by irradiating the target with a first pre-pulse laser beam having a wavelength of 1 μm, a second laser device that generates a low-density diffused target by irradiating the diffused target with a second pre-pulse laser beam having a wavelength of 1 μm, and a third laser device that generates extreme ultraviolet light by irradiating the low-density diffused target with a main pulse laser beam having a wavelength of 1 μm.

[0006] A method for manufacturing an electronic device according to one aspect of the present disclosure includes generating extreme ultraviolet light by an extreme ultraviolet light generation apparatus including: a chamber; a target supply unit that supplies a target into the chamber; a first laser apparatus that irradiates the target with first pre-pulse laser light having a wavelength of 1 μm to generate a diffused target that is convex in a traveling direction of the first pre-pulse laser light; a second laser apparatus that irradiates the diffused target with second pre-pulse laser light having a wavelength of 1 μm to generate a low-density diffused target; and a third laser apparatus that irradiates the low-density diffused target with main pulse laser light having a wavelength of 1 μm to generate extreme ultraviolet light; outputting the extreme ultraviolet light to an exposure apparatus; and exposing a photosensitive substrate in the exposure apparatus to the extreme ultraviolet light to manufacture an electronic device.

[0007] A method for manufacturing an electronic device according to one aspect of the present disclosure includes inspecting a mask for defects by irradiating the mask with extreme ultraviolet light generated by an extreme ultraviolet light generation apparatus including: a chamber; a target supply unit that supplies a target into the chamber; a first laser apparatus that irradiates the target with first pre-pulse laser light having a wavelength of 1 μm to generate a diffused target that is convex in a traveling direction of the first pre-pulse laser light; a second laser apparatus that irradiates the diffused target with second pre-pulse laser light having a wavelength of 1 μm to generate a low-density diffused target; and a third laser apparatus that irradiates the low-density diffused target with main pulse laser light having a wavelength of 1 μm to generate extreme ultraviolet light; selecting a mask using the results of the inspection; and exposing and transferring a pattern formed on the selected mask onto a photosensitive substrate. [Brief explanation of the drawings]

[0008] Some embodiments of the present disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which: [Figure 1] FIG. 1 shows the configuration of an LPP-type EUV light generation system according to a comparative example. [Figure 2] FIG. 2 shows how the target is irradiated with the first pre-pulse laser beam in the comparative example. [Figure 3] FIG. 3 shows how a diffused target is irradiated with a main pulse laser beam in a comparative example. [Figure 4] FIG. 4 shows the central portion of the diffused target in the comparative example, which is easily converted into plasma, and the peripheral portion, which is difficult to convert into plasma. [Figure 5] FIG. 5 shows the configuration of an EUV light generation system according to the first embodiment. [Figure 6] FIG. 6 shows pulse waveforms of the first pre-pulse laser beam, the second pre-pulse laser beam, and the main pulse laser beam that are focused in the plasma generation region in the first embodiment. [Figure 7] FIG. 7 shows how the target is irradiated with the first pre-pulse laser beam in the first embodiment. [Figure 8] FIG. 8 shows how the diffused target is irradiated with the second pre-pulse laser beam in the first embodiment. [Figure 9] FIG. 9 shows how a low-density diffused target is irradiated with a main pulse laser beam in the first embodiment. [Figure 10] FIG. 10 shows the setup for measuring a diffused target. [Figure 11] FIG. 11 is an image of a diffused target captured by an imaging unit in a comparative example. [Figure 12] FIG. 12 is an image obtained by binarizing FIG. [Figure 13] FIG. 13 is a graph showing the number of dark-point pixels at each position in the Y direction in FIG. [Figure 14] FIG. 14 is an image of a diffused target captured by the imaging unit in the first embodiment. [Figure 15] FIG. 15 is an image obtained by binarizing FIG. [Figure 16] FIG. 16 is a graph showing the number of dark-point pixels at each position in the Y direction in FIG. [Figure 17] FIG. 17 is an image obtained by simulating the shape of a diffused target under the irradiation conditions of the first embodiment. [Figure 18] FIG. 18 is an image obtained by simulating the shape of a low-density diffused target under the irradiation conditions of the first embodiment. [Figure 19] FIG. 19 shows the results of binarizing the image shown in FIG. 18 in the same manner as in FIGS. 12 and 15, and fitting a Gaussian function as an approximation curve for the number of pixels of dark spots in the same manner as in FIGS. [Figure 20] FIG. 20 is a graph showing the relationship between the delay time from when the target is irradiated with the first pre-pulse laser beam to when the diffused target is irradiated with the second pre-pulse laser beam and the conversion efficiency. [Figure 21]FIG. 21 is a graph showing the relationship between the delay time from when the target is irradiated with the first pre-pulse laser beam to when the diffused target is irradiated with the second pre-pulse laser beam and the ion energy of tin ions generated from the plasma generation region. [Figure 22] FIG. 22 shows the configuration of an EUV light generation system according to the second embodiment. [Figure 23] FIG. 23 shows a schematic configuration of an exposure tool connected to an EUV light generation system. [Figure 24] FIG. 24 shows a schematic configuration of an inspection device connected to an EUV light generation system. Embodiment

[0009] <Contents> 1. Comparative Example 1.1 Configuration 1.2 Operation 1.3 Issues with the comparative example 2. EUV light generation device 1 for generating a low-density diffused target 27c with a Gaussian distribution 2.1 Configuration 2.2 Operation 2.3 Irradiation conditions 2.4 Shape of the Diffusion Targets 27a and 27b 2.5 Shape of low-density diffused target 27c 2.6 Delay time Delay2 2.7 Effect 3. EUV light generation device 1 including polarization adjuster 349 3.1 Configuration 3.2 Operation 3.3 Effect 4.Other 4.1 Example of EUV light utilization equipment6 4.2 Processor 5 4.3 Supplementary Information

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

[0011] 1. Comparative Example 1.1 Configuration FIG. 1 shows the configuration of an LPP-type EUV light generation system 11 according to a comparative example. The comparative example in the present disclosure refers to a configuration that the applicant recognizes as being known only by the applicant, and is not a publicly known example that the applicant acknowledges. The EUV light generation system 1 is used together with a laser device 3. In the present disclosure, a system including the EUV light generation system 1 and the laser device 3 is referred to as an EUV light generation system 11.

[0012] The laser device 3 includes a first laser device PPL1 and a third laser device MPL. To facilitate comparison with the embodiments described below, the comparative examples may skip ordinal numbers such as first and second and use larger ordinal numbers common to the embodiments. The first laser device PPL1 outputs a first pre-pulse laser beam PP1 having a wavelength of 1 μm, and the third laser device MPL outputs a main pulse laser beam MP having a wavelength of 1 μm. The laser device outputting the 1 μm wavelength laser beam may be a Nd:YAG (neodymium-doped yttrium aluminum garnet) laser having a wavelength of 1.06 μm, a Yb:YAG (ytterbium-doped yttrium aluminum garnet) laser having a wavelength of 1.03 μm, or a Nd:YLF (neodymium-doped yttrium lithium fluoride) laser having a wavelength of 1.047 μm to 1.053 μm.

[0013] The EUV light generation system 1 includes a chamber 2 and a target supply unit 26. The chamber 2 is a sealable container. The target supply unit 26 supplies a target 27 containing tin as a target material into the chamber 2.

[0014] A through-hole is provided in the wall of the chamber 2. The through-hole is closed by a window 21, through which the pulsed laser beam 32 output from the laser device 3 passes. An EUV collector mirror 23 having a reflective surface with an ellipsoidal shape is disposed inside the chamber 2. A multilayer reflective film in which molybdenum and silicon are alternately stacked is formed on the reflective surface. The EUV collector mirror 23 has first and second focal points. The EUV collector mirror 23 is disposed so that its first focal point is located in the plasma generation region 25 and its second focal point is located at an intermediate focal point 292. A through-hole 24 is provided in the center of the EUV collector mirror 23, through which the pulsed laser beam 33 passes.

[0015] The EUV light generation system 1 includes a processor 5, a delay circuit 51, a target sensor 4, etc. The configuration of the processor 5 will be described later. The delay circuit 51 is configured to output first and third delayed trigger signals obtained by delaying a trigger signal output from the processor 5. The first delayed trigger signal is input to the first laser device PPL1, and the third delayed trigger signal is input to the third laser device MPL after the first delayed trigger signal. The target sensor 4 detects at least one of the presence, trajectory, position, and speed of the target 27. The target sensor 4 may have an imaging function.

[0016] The EUV light generation system 1 also includes a connection part 29 that connects the interior of the chamber 2 with the interior of the EUV light utilization system 6. The EUV light utilization system 6 may be an exposure system 6a shown in FIG. 23 or an inspection system 6b shown in FIG. 24. A wall 291 having an aperture formed therein is provided inside the connection part 29. The wall 291 is positioned so that the aperture is located at the second focal point of the EUV collector mirror 23.

[0017] The EUV light generation system 1 further includes a laser beam transmission device 34, a laser beam focusing optical system 22, and a target recovery unit 28 for recovering the target 27. The laser beam transmission device 34 includes optical elements such as high-reflection mirrors 341 to 343 and a second beam combiner 344, as well as actuators (not shown) for adjusting the positions, attitudes, etc. of these optical elements. The second beam combiner 344 is configured with a polarizing beam splitter. The laser beam focusing optical system 22 includes an off-axis parabolic concave mirror 221 and a high-reflection mirror 222.

[0018] 1.2 Operation The operation of the EUV light generation system 11 will be described with reference to FIG. 1. The laser device 3 outputs a first pre-pulse laser beam PP1 and a main pulse laser beam MP in this order in accordance with first and third delay trigger signals output from the delay circuit 51. The first pre-pulse laser beam PP1 is linearly polarized light having a polarization direction perpendicular to the plane of the drawing, and the main pulse laser beam MP is linearly polarized light having a polarization direction parallel to the plane of the drawing. The laser beam delivery device 34 causes the first pre-pulse laser beam PP1 and the main pulse laser beam MP to be incident on opposite surfaces of the second beam combiner 344 using high-reflection mirrors 341 to 343. The second beam combiner 344 reflects one of the first pre-pulse laser beam PP1 and the main pulse laser beam MP with high reflectivity and transmits the other with high transmittance, thereby allowing the optical path axes of these beams to be output from the laser beam delivery device 34 with approximately aligned axes. The first pre-pulse laser beam PP1 and the main pulse laser beam MP emitted from the laser beam transmission device 34 are collectively referred to as a pulse laser beam 32. The pulse laser beam 32 passes through the window 21 and enters the chamber 2. The pulse laser beam 32 passes through the laser beam focusing optical system 22 and is focused in the plasma generation region 25 as a pulse laser beam 33.

[0019] The target supply unit 26 outputs droplet-shaped targets 27 toward the plasma generation region 25 inside the chamber 2. FIG. 2 shows how the target 27 is irradiated with the first pre-pulse laser beam PP1 in a comparative example. The diameter of the target 27 is, for example, 15 μm. The target 27 irradiated with the first pre-pulse laser beam PP1 diffuses, becoming the diffused target 27a shown in FIG. 3. FIG. 3 shows how the diffused target 27a is irradiated with the main pulse laser beam MP in a comparative example. Compared to the droplet-shaped target 27, the diffused target 27a can impart energy of the main pulse laser beam MP to the diffused target 27a more efficiently.

[0020] At least a portion of the diffused target 27a irradiated with the main pulse laser beam MP is gasified, and a portion of the gasified target material is converted into plasma, which emits synchrotron radiation 251 (see FIG. 1 ). The EUV light contained in the synchrotron radiation 251 is reflected by the EUV collector mirror 23 with a higher reflectance than light in other wavelength ranges. Reflected light 252, which includes EUV light and is reflected by the EUV collector mirror 23, is collected at an intermediate focusing point 292 and output to the EUV light utilization device 6. In the following description, the output direction of the EUV light is defined as the +Z direction, and the output direction of the target 27 is defined as the -Y direction. The +Z direction and the -Y direction are perpendicular to each other, and the directions perpendicular to both the +Z direction and the -Y direction are defined as the +X direction and the -X direction.

[0021] The processor 5 controls the entire EUV light generation system 11. The processor 5 processes the detection results of the target sensor 4. Based on the detection results of the target sensor 4, the processor 5 controls the output direction of the target 27, the timing of the trigger signal to be output to the delay circuit 51, etc. Furthermore, the processor 5 controls the delay time set in the delay circuit 51, the traveling direction of the pulsed laser beam 32, the focusing position of the pulsed laser beam 33, etc. The various controls described above are merely examples, and other controls may be added as necessary.

[0022] 1.3 Issues with the comparative example The irradiation conditions of the first pre-pulse laser beam PP1 and the main pulse laser beam MP in the comparative example are as follows. The light intensity I at the position where the first pre-pulse laser beam PP1 is irradiated onto the target 27 PP1 :3.7×10 7 W / cm 2 The pulse width T of the first pre-pulse laser beam PP1 PP1 :80ns The light intensity I of the main pulse laser beam MP at the position where the diffused target 27a is irradiated MP :5.4×10 10 W / cm 2 Pulse width T of the main pulse laser light MP MP :20ns Delay time from when the target 27 is irradiated with the first pre-pulse laser beam PP1 to when the diffused target 27a is irradiated with the main pulse laser beam MP (Delay 1: 100 ns)

[0023] Pulse width T PP1 and T MP is the full width at half maximum. Light intensity I PP1 and I MP is the pulse energy E, the pulse width T, the focused diameter, i.e., 1 / e of the peak intensity at the position where the target 27 or the diffused target 27a is irradiated. 2 When the total width of the part having the above strength is D, it corresponds to I given by the following formula. I=(E / (π(D / 2) 2 )) / T

[0024] The delay time Delay1 is the time difference between the peak times in the pulse time waveforms of the first pre-pulse laser beam PP1 and the main pulse laser beam MP, and is set depending on the time required from when the target 27 is irradiated with the first pre-pulse laser beam PP1 until the diffused target 27a becomes a spheroid having a diameter equal to or smaller than the focused diameter of the main pulse laser beam MP, for example, 45 μm.

[0025] 4 shows a central portion 271 of a diffused target 27a in a comparative example, which is easily converted to plasma, and a peripheral portion 272 of the diffused target 27a which is difficult to convert to plasma. Because the main pulse laser beam MP has an intensity peak at the center of its optical path, a large amount of energy is imparted to the central portion 271 of the diffused target 27a. However, a peripheral portion 272 of the diffused target 27a, which is distant from the central portion 271, does not receive as much energy as the central portion 271, even though a large amount of target material is distributed therein. For this reason, even if the overall energy of the main pulse laser beam MP is increased, the peripheral portion 272 may not be sufficiently converted to plasma.

[0026] Under the irradiation conditions of the comparative example, the conversion efficiency CE from laser light energy to EUV light energy, CEcom, is 1.32%. Further improvement in the conversion efficiency CE is desired.

[0027] 2. EUV light generation device 1 for generating a low-density diffused target 27c with a Gaussian distribution 2.1 Configuration 5 shows the configuration of an EUV light generation system 11a according to the first embodiment. In the first embodiment, the laser apparatus 3 includes a second laser apparatus PPL2, and the laser beam transmission device 34 includes a first beam combiner 345, a high-reflection mirror 346, and a beam dumper 347.

[0028] The second laser device PPL2 has a configuration similar to that of the first laser device PPL1. The first beam combiner 345 is composed of a partially reflecting mirror, and its reflectance is, for example, 10% to 90%. The first beam combiner 345 is disposed at a position where the optical paths of the first pre-pulse laser beam PP1 output from the first laser device PPL1 and the second pre-pulse laser beam PP2 output from the second laser device PPL2 overlap, and is obliquely disposed with respect to these optical paths.

[0029] 2.2 Operation The delay circuit 51 outputs a second delayed trigger signal between the first and third delayed trigger signals. The second laser device PPL2 outputs a second pre-pulse laser beam PP2 having a wavelength of 1 μm in accordance with the second delayed trigger signal. The second pre-pulse laser beam PP2 is linearly polarized light having the same polarization direction as the first pre-pulse laser beam PP1.

[0030] The first pre-pulse laser beam PP1 passes through the high-reflection mirror 341 and is incident on a first surface of the first beam combiner 345, and the second pre-pulse laser beam PP2 is incident on a second surface of the first beam combiner 345 opposite the first surface. The first beam combiner 345 reflects a first portion of the first pre-pulse laser beam PP1 and transmits a second portion of the second pre-pulse laser beam PP2, thereby guiding the first and second portions to a first optical path L1. The first and second portions propagating through the first optical path L1 are reflected by a high-reflection mirror 346 and enter the second beam combiner 344. The second beam combiner 344 guides the first and second portions and the main pulse laser beam MP to a second optical path L2 and outputs them from the laser beam delivery device 34. The first beam combiner 345 transmits a third portion of the first pre-pulse laser beam PP1 that is different from the first portion and reflects a fourth portion of the second pre-pulse laser beam PP2 that is different from the second portion, thereby guiding the third and fourth portions to a third optical path L3. The beam dumper 347 is located on the third optical path L3 and absorbs the energy of the third and fourth portions. The first beam combiner 345 may transmit the first portion, reflect the second portion, and guide it to the first optical path L1, and may reflect the third portion and transmit the fourth portion and guide it to the third optical path L3.

[0031] In this way, the first portion of the first pre-pulse laser beam PP1, the second portion of the second pre-pulse laser beam PP2, and the main pulse laser beam MP, which are substantially coaxial in the second optical path L2, enter the chamber 2 in this order and are focused in the plasma generation region 25. Hereinafter, the term "first pre-pulse laser beam PP1" may be used to refer to only the first portion, and the term "second pre-pulse laser beam PP2" may be used to refer to only the second portion.

[0032] 2.3 Irradiation conditions 6 shows the pulse waveforms of the first pre-pulse laser beam PP1, the second pre-pulse laser beam PP2, and the main pulse laser beam MP that are focused in the plasma generation region 25 in the first embodiment. The delay time Delay2 is the time difference between the peak times in the pulse time waveforms of the first pre-pulse laser beam PP1 and the second pre-pulse laser beam PP2.

[0033] Fig. 7 shows how the target 27 is irradiated with the first pre-pulse laser beam PP1 in the first embodiment. Fig. 8 shows how the diffused target 27b is irradiated with the second pre-pulse laser beam PP2 in the first embodiment. Fig. 9 shows how the low-density diffused target 27c is irradiated with the main pulse laser beam MP in the first embodiment.

[0034] Light intensity I of the first pre-pulse laser beam PP1 PP1 is 2.2 x 10 7 W / cm 2 Over 3.6 x 10 7 W / cm 2 The light intensity I PP1 As a result, a diffused target 27b that is convex in the direction of propagation of the first pre-pulse laser beam PP1 is generated as shown in FIG. PP1 The preferred value of is 2.3×10 7 W / cm 2 The pulse width T of the first pre-pulse laser beam PP1 PP1 The pulse width T is between 60ns and 100ns. PP1 The preferred value is 80 ns, the same as in the comparative example.

[0035] The delay time Delay2 from when the first pre-pulse laser beam PP1 is irradiated onto the target 27 to when the second pre-pulse laser beam PP2 is irradiated onto the diffused target 27b is preferably 150 ns or more and 250 ns or less. The delay time Delay2 will be described later with reference to FIGS. 20 and 21.

[0036] Light intensity I of the second pre-pulse laser beam PP2 PP2 is 0.5 x 10 8 W / cm 2 Over 5.0 x 10 8 W / cm 2 As a result, a low-density diffused target 27c is generated that is convex in the direction of propagation of the second pre-pulse laser beam PP2, as shown in FIG. PP2 The preferred value of is 1.1×10 8 W / cm 2 The pulse width T of the second pre-pulse laser beam PP2 PP2 The pulse width T is between 1 ns and 20 ns. PP2 is the pulse width T PP1 It is preferable that the pulse width is between 1 / 100 and 1 / 5 of the PP2 A preferred value for is 7 ns.

[0037] The delay time Delay1 from when the first pre-pulse laser beam PP1 is irradiated onto the target 27 to when the main pulse laser beam MP is irradiated onto the low-density diffused target 27c is preferably 200 ns or more and 400 ns or less. However, if the delay time Delay2 is 200 ns or more, the delay time Delay1 is longer than the delay time Delay2. A preferred value for the delay time Delay1 is 300 ns.

[0038] Light intensity I of the main pulse laser light MP MP is 3.0 x 10 10 W / cm 2 Over 6.6 x 10 10 W / cm 2 The light intensity I MP The preferred value is 5.4 × 10 10 W / cm 2 The pulse width T of the main pulse laser light MP MP The pulse width T is between 10ns and 30ns. MP The preferred value is 20 ns, the same as in the comparative example.

[0039] The main pulse laser beam MP has a Gaussian light intensity distribution. The focused diameter of the main pulse laser beam MP is preferably equal to or smaller than the size of the low-density diffused target 27c in a direction perpendicular to the Z direction, and is in the range of 30 μm to 100 μm, depending on the size of the low-density diffused target 27c.

[0040] 2.4 Shape of the Diffusion Targets 27a and 27b FIG. 10 shows the configuration of an apparatus for measuring diffused targets 27a and 27b. FIG. 10 corresponds to a view of the interior of chamber 2 as viewed in the -Y direction, which is the output direction of target 27. Two windows 21a and 21b are arranged in chamber 2, sandwiching plasma generation region 25, where diffused target 27a or 27b is generated. A white flashlight 41 and an image capture unit 42 are arranged outside chamber 2, sandwiching windows 21a and 21b. Other components inside chamber 2 are not shown in the illustration.

[0041] After the target 27 is irradiated with the first pre-pulse laser beam PP1, the white flashlight 41 generates a light beam 43 that perpendicularly intersects the optical path axis of the first pre-pulse laser beam PP1 in the plasma generation region 25 when a delay time Delay1 has elapsed. At this time, neither the second pre-pulse laser beam PP2 nor the main pulse laser beam MP is irradiated. A portion of the light beam 43 passes through the diffused target 27a or 27b and its surroundings and is incident on the imaging unit 42, which then captures an image of the shape of the diffused target 27a or 27b. A pulsed laser or a light-emitting diode may be used instead of the white flashlight 41.

[0042] Fig. 11 is an image of the diffused target 27a captured by the imaging unit 42 in the comparative example, and Fig. 14 is an image of the diffused target 27b captured by the imaging unit 42 in the first embodiment. Figs. 11 and 14 correspond to images of a space 86 µm in the Y direction and 43 µm in the Z direction near the plasma generation region 25. The +Z direction is the traveling direction of the first pre-pulse laser beam PP1. The mist-like target material contained in the diffused target 27a or 27b scatters or absorbs part of the light beam 43 generated by the white flashlight 41, and thereby appears as a dark portion in the image.

[0043] Figures 12 and 15 are images obtained by binarizing Figures 11 and 14, respectively. Figures 13 and 16 are graphs showing the number of dark spot pixels at each position in the Y direction in Figures 12 and 15, respectively, where the horizontal axis represents the position in the Y direction and the vertical axis represents the number of dark spot pixels.

[0044] In the first embodiment, the number of dark spots peaks near the position of Y=43 μm, and the number of dark spots decreases in the +Y direction or the −Y direction from the peak position. When a Gaussian function shown by the broken line in FIG. 16 was fitted as an approximation curve of the number of dark spots, the coefficient of determination R 2 was 0.96198, and the distribution of the number of pixels of the scotoma was very similar to the Gaussian distribution.

[0045] In contrast, in the comparative example, the number of dark spots is distributed almost evenly in the space from the vicinity of the position Y=20 μm to the vicinity of the position Y=60 μm. When a Gaussian function shown by the dashed line in FIG. 13 is fitted as an approximation curve of the number of dark spots, the coefficient of determination R 2 was 0.87197, and the distribution of the number of pixels of the scotoma did not match the Gaussian distribution.

[0046] 2.5 Shape of low-density diffused target 27c Fig. 17 is an image obtained by simulating the shape of diffused target 27b under the irradiation conditions of the first embodiment, and Fig. 18 is an image obtained by simulating the shape of low-density diffused target 27c under the irradiation conditions of the first embodiment. When diffused target 27b is irradiated with second pre-pulse laser beam PP2, slight plasma emission occurs, which is difficult to measure using the apparatus shown in Fig. 10, so the shape of low-density diffused target 27c was obtained by simulation.

[0047] The diffusion target 27b shown in Fig. 17 has a shape that includes gentle slopes near both ends in the Y direction and a raised portion near the center in the Y direction, which closely matches the shape of the diffusion target 27b shown in Fig. 14 or 15. This indicates that the simulation is highly reliable.

[0048] The low-density diffused target 27c shown in Figure 18 has a flat shape that is shorter in the Z direction than the diffused target 27b, but it has a shape similar to a Gaussian distribution in that it includes gently sloping portions near both ends in the Y direction and a raised portion near the center in the Y direction.

[0049] Fig. 19 shows the results of binarizing the image shown in Fig. 18 in the same way as Figs. 12 and 15, and fitting a Gaussian function as an approximation curve for the number of pixels of dark spots in the same way as Figs. 13 and 16. In Fig. 19, the coefficient of determination R 2 was 0.99101, and the distribution of the number of pixels of the scotoma was very similar to the Gaussian distribution.

[0050] As described above, the intensity distribution of the main pulse laser beam MP is a Gaussian distribution. The coefficient of determination R of the intensity distribution of the main pulse laser beam MP for a Gaussian function is 2 A value of 0.99 or higher is desirable.

[0051] In the first embodiment, diffused target 27b is irradiated with second pre-pulse laser beam PP2 to generate low-density diffused target 27c having a Gaussian distribution convex in the direction of propagation of second pre-pulse laser beam PP2, and main pulse laser beam MP having a Gaussian intensity distribution is irradiated onto low-density diffused target 27c. Accordingly, a central portion of low-density diffused target 27c where a large amount of target material is present is irradiated with a central portion of main pulse laser beam MP having a high intensity, and therefore, it is considered that the energy of main pulse laser beam MP is efficiently imparted to low-density diffused target 27c and turns it into plasma. The coefficient of determination R for the Gaussian function of the distribution shape of low-density diffused target 27c is 2 It is desirable that the ratio be 0.95 or higher.

[0052] It is desirable to make the distribution of the target material in the diffused target 27b coincide with the intensity distribution of the second pre-pulse laser beam PP2, and to make the distribution of the target material in the low-density diffused target 27c coincide with the intensity distribution of the main pulse laser beam MP. To achieve this, it is desirable that the propagation directions of the first pre-pulse laser beam PP1, the second pre-pulse laser beam PP2, and the main pulse laser beam MP are as similar as possible. It is desirable that the deviation in the direction of any two of these optical path axes is 1° or less.

[0053] 2.6 Delay time Delay2 20 is a graph showing the relationship between the delay time Delay2 from when the target 27 is irradiated with the first pre-pulse laser beam PP1 to when the diffused target 27b is irradiated with the second pre-pulse laser beam PP2 and the conversion efficiency CE. In the first embodiment, even when the delay time Delay2 is changed from 0 ns to 300 ns, there is no significant difference in the conversion efficiency CE, and the average value CEavg of the conversion efficiency CE is 1.58%. According to the first embodiment, a higher conversion efficiency CE is obtained compared to the comparative example, where the conversion efficiency CE value CEcom was 1.32%, but the value of the conversion efficiency CE does not change significantly depending on the delay time Delay2. From this, it is estimated that irradiating the diffused target 27b with the second pre-pulse laser beam PP2 does not significantly change the shape of the diffused target 27b to the low-density diffused target 27c, and that the low-density diffused target 27c has a Gaussian distribution-like shape.

[0054] 21 is a graph showing the relationship between the delay time Delay2 from when the target 27 is irradiated with the first pre-pulse laser beam PP1 to when the diffused target 27b is irradiated with the second pre-pulse laser beam PP2 and the ion energy EION of tin ions generated from the plasma generation region 25. The ion energy EIONcom of the tin ions in the comparative example was 1.37 keV. In contrast, in the first embodiment, it was found that the ion energy EION of the tin ions was low when the delay time Delay2 was in the range of 150 ns or more and 250 ns or less. The average value EIONavg of the ion energy EION of the tin ions in the range of 150 ns or more and 250 ns or less was 1.15 keV. A low ion energy EION of the tin ions has the effect of suppressing the progression of deterioration of optical components such as the EUV collector mirror 23 in the chamber 2.

[0055] 2.7 Effect (1) According to the first embodiment, the EUV light generation system 1 includes a chamber 2, a target supply unit 26, a first laser device PPL1, a second laser device PPL2, and a third laser device MPL. The target supply unit 26 supplies a target 27 into the chamber 2. The first laser device PPL1 irradiates the target 27 with a first pre-pulse laser beam PP1 having a wavelength of 1 μm to generate a diffused target 27 b that is convex in the propagation direction of the first pre-pulse laser beam PP1. The second laser device PPL2 irradiates the diffused target 27 b with a second pre-pulse laser beam PP2 having a wavelength of 1 μm to generate a low-density diffused target 27 c. The third laser device MPL irradiates the low-density diffused target 27 c with a main pulse laser beam MP having a wavelength of 1 μm to generate EUV light.

[0056] According to this, the diffused target 27b that is convex in the traveling direction of the first pre-pulse laser beam PP1 is generated by irradiation with the first pre-pulse laser beam PP1, and the low-density diffused target 27c is generated by irradiation with the second pre-pulse laser beam PP2, so that the energy of the main pulse laser beam MP can be efficiently imparted to the low-density diffused target 27c. This can improve the conversion efficiency CE. Furthermore, since the focused diameter can be reduced by using the main pulse laser beam MP having a wavelength of 1 μm, the size of the EUV light emission region can be reduced, and EUV light with high brightness can be generated.

[0057] (2) According to the first embodiment, the second laser device PPL2 irradiates the diffused target 27b with the second pre-pulse laser beam PP2 to generate the low-density diffused target 27c having a Gaussian distribution convex in the propagation direction of the second pre-pulse laser beam PP2. The third laser device MPL irradiates the low-density diffused target 27c with the main pulse laser beam MP having a Gaussian intensity distribution.

[0058] According to this, by making the low-density diffused target 27c have a Gaussian distribution, the energy of the main pulse laser beam MP having a Gaussian intensity distribution can be efficiently imparted to the low-density diffused target 27c, and the conversion efficiency CE can be improved.

[0059] (3) According to the first embodiment, the coefficient of determination R for the Gaussian function of the distribution shape of the low-density diffused target 27c 2 is 0.95 or greater.

[0060] According to this, since the distribution shape of the low-density diffused target 27c is close to a Gaussian distribution, the energy of the main pulse laser beam MP is efficiently imparted to many parts of the low-density diffused target 27c.

[0061] (4) According to the first embodiment, the light intensity I at the position where the first pre-pulse laser beam PP1 is irradiated onto the target 27 is PP1 is 2.2 x 10 7 W / cm 2 Over 3.6 x 10 7 W / cm 2 The following is the result.

[0062] According to this, the light intensity I PP1 By making it lower than that of the comparative example, a diffused target 27b with a Gaussian distribution can be generated, and can be efficiently converted into plasma by irradiation with the second pre-pulse laser beam PP2 and the main pulse laser beam MP, thereby improving the conversion efficiency CE.

[0063] (5) According to the first embodiment, the light intensity I PP2 is 0.5 x 10 8 W / cm 2 Over 5.0 x 10 8 W / cm 2 The following is the result.

[0064] According to this, the diffusion target 27b is ablated to generate the low-density diffusion target 27c, thereby improving the absorption efficiency of the main pulse laser beam MP and achieving a high conversion efficiency CE.

[0065] (6) According to the first embodiment, the light intensity I at the position where the main pulse laser beam MP is irradiated onto the low-density diffused target 27c is MP is 3.0 x 10 10 W / cm 2 Over 6.6 x 10 10 W / cm 2 The following is the result.

[0066] This allows the low-density diffused target 27c to be efficiently converted into plasma, thereby achieving a high conversion efficiency CE.

[0067] (7) According to the first embodiment, the delay time Delay2 from when the target 27 is irradiated with the first pre-pulse laser beam PP1 to when the diffused target 27b is irradiated with the second pre-pulse laser beam PP2 is 150 ns or more and 250 ns or less.

[0068] This makes it possible to reduce the ion energy E ION of tin ions emitted from the plasma, and to suppress deterioration of the optical elements.

[0069] (8) According to the first embodiment, the delay time Delay1 from when the target 27 is irradiated with the first pre-pulse laser beam PP1 to when the low-density diffused target 27c is irradiated with the main pulse laser beam MP is not less than 200 ns and not more than 400 ns.

[0070] Within this delay time Delay1, the Gaussian distribution shape of the low-density diffused target 27c can be maintained, and therefore the low-density diffused target 27c can be efficiently converted into plasma by the main pulse laser beam MP.

[0071] (9) According to the first embodiment, the focused diameter of the main pulse laser beam MP is not less than 30 μm and not more than 100 μm.

[0072] According to this, since the difference between the size of the low-density diffused target 27c and the focused diameter of the main pulse laser beam MP is small, the low-density diffused target 27c can be efficiently converted into plasma by the main pulse laser beam MP.

[0073] (10) According to the first embodiment, the pulse width T PP1 is between 60ns and 100ns.

[0074] According to this, the target 27 is ablated over time by the first pre-pulse laser beam PP1, thereby obtaining a diffused target 27b with a Gaussian distribution, which can be efficiently converted into plasma by irradiation with the second pre-pulse laser beam PP2 and the main pulse laser beam MP.

[0075] (11) According to the first embodiment, the pulse width T PP2 is between 1 ns and 20 ns.

[0076] This makes it possible to generate the low-density diffused target 27c without significantly changing the shape of the diffused target 27b.

[0077] (12) According to the first embodiment, the pulse width T PP2 is the pulse width T of the first pre-pulse laser beam PP1 PP1 It is more than one-hundredth and less than one-fifth of the

[0078] This makes it possible to generate the low-density diffused target 27c with a Gaussian distribution without significantly changing the shape of the diffused target 27b with a Gaussian distribution generated by irradiation with the first pre-pulse laser beam PP1.

[0079] (13) According to the first embodiment, the pulse width T MP is between 10ns and 30ns.

[0080] This allows the low-density diffused target 27c to be efficiently converted into plasma by the main pulse laser beam MP.

[0081] (14) According to the first embodiment, the deviation of the directions of any two optical path axes of the first pre-pulse laser beam PP1, the second pre-pulse laser beam PP2, and the main pulse laser beam MP is 1° or less.

[0082] This allows the distribution of the target material in the diffused target 27b to approximately match the intensity distribution of the second pre-pulse laser beam PP2, and the distribution of the target material in the low-density diffused target 27c to approximately match the intensity distribution of the main pulse laser beam MP, thereby efficiently converting the target material into plasma.

[0083] (15) According to the first embodiment, the EUV light generation system 1 includes a first beam combiner 345 and a beam dumper 347. The first beam combiner 345 guides a first portion of the first pre-pulse laser beam PP1 and a second portion of the second pre-pulse laser beam PP2 to a first optical path L1. The second beam combiner 344 guides the first and second portions propagating through the first optical path L1 and the main pulse laser beam MP to a second optical path L2. The first beam combiner 345 guides a third portion of the first pre-pulse laser beam PP1, which is different from the first portion, and a fourth portion of the second pre-pulse laser beam PP2, which is different from the second portion, to a third optical path L3, which is different from the first optical path L1. The beam dumper 347 is located on the third optical path L3.

[0084] When the wavelengths of the first pre-pulse laser beam PP1, the second pre-pulse laser beam PP2, and the main pulse laser beam MP are close to one another, if one of the three light beams has a polarization direction different from the others, the optical paths can be combined with little loss, but the remaining two may incur losses when combining the optical paths. By allowing losses when combining the optical paths of the first pre-pulse laser beam PP1 and the second pre-pulse laser beam PP2, it is possible to reduce losses when combining with the main pulse laser beam MP and suppress overall losses.

[0085] Other points are the same as those of the comparative example.

[0086] 3. EUV light generation device 1 including polarization adjuster 349 3.1 Configuration 22 shows the configuration of an EUV light generation system 11b according to the second embodiment. In the second embodiment, the laser beam transmission device 34 includes a first beam combiner 348 instead of the first beam combiner 345 (see FIG. 5). The laser beam transmission device 34 does not need to include the beam dumper 347, but includes a polarization adjuster 349. The first beam combiner 348 is configured as a polarizing beam splitter. The polarization adjuster 349 includes, for example, an electro-optical element and a power supply, and is disposed on the first optical path L1 between the first beam combiner 348 and the second beam combiner 344. The polarization adjuster 349 is configured to be switchable between a first state in which the polarization direction of linearly polarized light passing through the electro-optical element is rotated by 90° and a second state in which the linearly polarized light passes without being rotated, in response to a control signal received from the processor 5.

[0087] 3.2 Operation In the second embodiment, the polarization direction of the second pre-pulse laser beam PP2 output from the second laser device PPL2 is different from the polarization direction of the first pre-pulse laser beam PP1 output from the first laser device PPL1 and is parallel to the plane of the page. The first beam combiner 348 reflects one of the first and second pre-pulse laser beams PP1 and PP2 with high reflectivity and transmits the other with high transmittance, thereby guiding the first and second pre-pulse laser beams PP1 and PP2 to the first optical path L1.

[0088] The processor 5 switches the state of the polarization adjuster 349 between when the first pre-pulse laser beam PP1 passes through the polarization adjuster 349 and when the second pre-pulse laser beam PP2 passes through the polarization adjuster 349, so that the polarization directions of the first and second pre-pulse laser beams PP1 and PP2 that have passed through the polarization adjuster 349 become a third polarization direction. The third polarization direction may be the same as either the first or second polarization direction.

[0089] The second beam combiner 344 reflects one of the first and second pre-pulse laser beams PP1 and PP2 and the main pulse laser beam MP and transmits the other, thereby guiding the first and second pre-pulse laser beams PP1 and PP2 and the main pulse laser beam MP to the second optical path L2 and outputting them from the laser beam transmission device 34.

[0090] In this manner, the first pre-pulse laser beam PP1, the second pre-pulse laser beam PP2, and the main pulse laser beam MP, which are substantially coaxial in the second optical path L2, enter the chamber 2 in this order and are focused in the plasma generation region 25.

[0091] 3.3 Effect (16) According to the second embodiment, the EUV light generation system 1 includes a first beam combiner 348, a polarization adjuster 349, a processor 5, and a second beam combiner 344. The first beam combiner 348 guides a first pre-pulse laser beam PP1 having a first polarization direction and a second pre-pulse laser beam PP2 having a second polarization direction different from the first polarization direction to a first optical path L1. The polarization adjuster 349 is disposed on the first optical path L1. The processor 5 switches the state of the polarization adjuster 349 between when the first pre-pulse laser beam PP1 passes through the polarization adjuster 349 and when the second pre-pulse laser beam PP2 passes through the polarization adjuster 349, so that the polarization directions of the first and second pre-pulse laser beams PP1 and PP2 that have passed through the polarization adjuster 349 become a third polarization direction. The second beam combiner 344 guides the first and second pre-pulse laser beams PP1 and PP2 having the third polarization direction and the main pulse laser beam MP having a fourth polarization direction different from the third polarization direction to a second optical path L2.

[0092] According to this, after combining the optical paths of the first pre-pulse laser beam PP1 and the second pre-pulse laser beam PP2 having different polarization directions, the polarization direction of the pre-pulse laser beam PP2 is made different from the polarization direction of the main pulse laser beam MP, so that the optical paths of the three light beams can be combined with little loss.

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

[0094] 4.Other 4.1 Example of EUV light utilization equipment6 FIG. 23 shows a schematic configuration of an exposure apparatus 6a connected to the EUV light generation system 11a. The exposure apparatus 6a, which serves as the EUV light utilization apparatus 6 (see FIG. 5), includes a mask illumination unit 608 and a workpiece illumination unit 609. The mask illumination unit 608 illuminates a mask pattern on a mask table MT via a reflection optical system with EUV light incident from the EUV light generation system 11a. The workpiece illumination unit 609 forms an image of the EUV light reflected by the mask table MT onto a workpiece (not shown) placed on a workpiece table WT via a reflection optical system. The workpiece is a photosensitive substrate such as a semiconductor wafer coated with photoresist. The exposure apparatus 6a exposes the workpiece to EUV light reflecting the mask pattern by synchronously translating the mask table MT and the workpiece table WT. Electronic devices can be manufactured by transferring a device pattern onto a semiconductor wafer using the exposure process described above.

[0095] FIG. 24 schematically illustrates the configuration of the inspection apparatus 6b connected to the EUV light generation system 11a. The inspection apparatus 6b, which serves as the EUV light utilization apparatus 6 (see FIG. 5), includes an illumination optical system 603 and a detection optical system 606. The illumination optical system 603 reflects EUV light incident from the EUV light generation system 11a and irradiates a mask 605 placed on a mask stage 604. The mask 605 here refers to a mask blank before a pattern is formed. The detection optical system 606 reflects the EUV light from the illuminated mask 605 and forms an image on the light-receiving surface of a detector 607. The detector 607 receives the EUV light and acquires an image of the mask 605. The detector 607 is, for example, a TDI (time delay integration) camera. The image of the mask 605 acquired through the above process is used to inspect the mask 605 for defects, and the inspection results are used to select a mask suitable for manufacturing electronic devices. The pattern formed on the selected mask is then exposed and transferred onto a photosensitive substrate using the exposure apparatus 6a, thereby manufacturing an electronic device.

[0096] 23 and 24, an EUV light generation system 11b may be used instead of the EUV light generation system 11a.

[0097] 4.2 Processor 5 The processor 5 may be physically configured in the form of hardware to execute various processes included in the present disclosure. For example, the processor 5 may be a computer including a memory storing a control program that defines the various processes and a processing device that executes the control program. The control program may be stored in a single memory, or may be stored separately in multiple physically separate memories, with the various processes defined by the control program as a collection of these memories. The processing device may be a general-purpose processing device such as a CPU, or a processing device for a specific purpose such as a GPU.

[0098] The processor 5 may be programmed in the form of software to execute various processes included in the present disclosure. For example, the processor 5 may be a device in which the functions for executing various processes are implemented in a dedicated device such as an ASIC or a programmable device such as an FPGA.

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

[0100] 4.3 Supplementary Information The above description is intended to be illustrative rather than limiting. Thus, it will be apparent to one skilled in the art that modifications can be made to the disclosed embodiments without departing from the scope of the claims. It will also be apparent to one skilled in the art that the disclosed embodiments can be used in combination.

[0101] Terms used throughout this specification and claims should be construed as "open ended" unless expressly stated otherwise. For example, words such as "comprise," "have," "comprise," and "equip" should be construed as meaning "without excluding the presence of elements other than those listed." In addition, the modifier "a" should be construed as meaning "at least one" or "one or more." In addition, the term "at least one of A, B, and C" should be construed as "A," "B," "C," "A+B," "A+C," "B+C," or "A+B+C," and should also be construed as including combinations other than "A," "B," and "C."

Claims

1. a chamber; a target supply unit that supplies a target into the chamber; a first laser device that generates a diffused target that is convex in a traveling direction of the first pre-pulse laser beam by irradiating the target with a first pre-pulse laser beam having a wavelength of 1 μm; a second laser device that generates a low-density diffused target by irradiating the diffused target with a second pre-pulse laser beam having a wavelength of 1 μm; a third laser device that generates extreme ultraviolet light by irradiating the low-density diffused target with a main pulse laser beam having a wavelength of 1 μm; An extreme ultraviolet light generating device comprising:

2. 2. The extreme ultraviolet light generating apparatus according to claim 1, the second laser device generates the low-density diffused target having a Gaussian distribution that is convex in a propagation direction of the second pre-pulse laser beam by irradiating the diffused target with the second pre-pulse laser beam; the third laser device irradiates the low-density diffused target with the main pulse laser beam having a Gaussian intensity distribution; Extreme ultraviolet light generator.

3. 3. The extreme ultraviolet light generating apparatus according to claim 2, The coefficient of determination of the distribution shape of the low-density diffuse target with respect to a Gaussian function is 0.95 or more. Extreme ultraviolet light generator.

4. 2. The extreme ultraviolet light generating apparatus according to claim 1, The light intensity of the first pre-pulse laser light at the position where the target is irradiated is 2.2×10 ７ W / cm ２ 3.6 x 10 ７ W / cm ２ Below is the Extreme ultraviolet light generator.

5. 2. The extreme ultraviolet light generating apparatus according to claim 1, The light intensity of the second pre-pulse laser light at the position where the diffused target is irradiated is 0.5×10 ８ W / cm ２ Above 5.0 x 10 ８ W / cm ２ Below is the Extreme ultraviolet light generator.

6. 2. The extreme ultraviolet light generating apparatus according to claim 1, The light intensity of the main pulse laser light at the position where the low-density diffused target is irradiated is 3.0×10 １０ W / cm ２ 6.6 x 10 １０ W / cm ２ Below is the Extreme ultraviolet light generator.

7. 2. The extreme ultraviolet light generating apparatus according to claim 1, a delay time from when the target is irradiated with the first pre-pulse laser beam to when the diffused target is irradiated with the second pre-pulse laser beam is 150 ns or more and 250 ns or less; Extreme ultraviolet light generator.

8. 2. The extreme ultraviolet light generating apparatus according to claim 1, a delay time from when the target is irradiated with the first pre-pulse laser beam to when the low-density diffused target is irradiated with the main pulse laser beam is 200 ns or more and 400 ns or less; Extreme ultraviolet light generator.

9. 2. The extreme ultraviolet light generating apparatus according to claim 1, the focused diameter of the main pulse laser beam is 30 μm or more and 100 μm or less; Extreme ultraviolet light generator.

10. 2. The extreme ultraviolet light generating apparatus according to claim 1, a pulse width of the first pre-pulse laser beam is equal to or greater than 60 ns and equal to or less than 100 ns; Extreme ultraviolet light generator.

11. 2. The extreme ultraviolet light generating apparatus according to claim 1, the pulse width of the second pre-pulse laser beam is 1 ns or more and 20 ns or less; Extreme ultraviolet light generator.

12. 2. The extreme ultraviolet light generating apparatus according to claim 1, a pulse width of the second pre-pulse laser beam is equal to or greater than 1 / 100 and equal to or less than 1 / 5 of the pulse width of the first pre-pulse laser beam; Extreme ultraviolet light generator.

13. 2. The extreme ultraviolet light generating apparatus according to claim 1, the pulse width of the main pulse laser beam is 10 ns or more and 30 ns or less; Extreme ultraviolet light generator.

14. 2. The extreme ultraviolet light generating apparatus according to claim 1, any two optical path axes of the first pre-pulse laser beam, the second pre-pulse laser beam, and the main pulse laser beam are misaligned by 1° or less; Extreme ultraviolet light generator.

15. 2. The extreme ultraviolet light generating apparatus according to claim 1, a first beam combiner that guides a first portion of the first pre-pulse laser beam and a second portion of the second pre-pulse laser beam to a first optical path; a second beam combiner that guides the first portion and the second portion propagating through the first optical path and the main pulse laser beam to a second optical path; A beam dumper; Furthermore, the first beam combiner is configured to guide a third portion of the first pre-pulse laser beam different from the first portion and a fourth portion of the second pre-pulse laser beam different from the second portion to a third optical path different from the first optical path; the beam dumper is located in the third optical path. Extreme ultraviolet light generator.

16. 2. The extreme ultraviolet light generating apparatus according to claim 1, a first beam combiner that guides the first pre-pulse laser beam having a first polarization direction and the second pre-pulse laser beam having a second polarization direction different from the first polarization direction to a first optical path; a polarization adjuster disposed in the first optical path; a processor that switches a state of the polarization adjuster between when the first pre-pulse laser beam passes through the polarization adjuster and when the second pre-pulse laser beam passes through the polarization adjuster so that the polarization directions of the first and second pre-pulse laser beams that have passed through the polarization adjuster become a third polarization direction; a second beam combiner that guides the first and second pre-pulse laser beams having the third polarization direction and the main pulse laser beam having a fourth polarization direction different from the third polarization direction to a second optical path; The extreme ultraviolet light generating device further comprises:

17. A method for manufacturing an electronic device, comprising: a chamber; a target supply unit that supplies a target into the chamber; a first laser device that generates a diffused target that is convex in a traveling direction of the first pre-pulse laser beam by irradiating the target with a first pre-pulse laser beam having a wavelength of 1 μm; a second laser device that generates a low-density diffused target by irradiating the diffused target with a second pre-pulse laser beam having a wavelength of 1 μm; a third laser device that generates extreme ultraviolet light by irradiating the low-density diffused target with a main pulse laser beam having a wavelength of 1 μm; The extreme ultraviolet light is generated by an extreme ultraviolet light generating device comprising: outputting the extreme ultraviolet light to an exposure device; exposing a photosensitive substrate to the extreme ultraviolet light in the exposure apparatus to manufacture an electronic device; A method for manufacturing an electronic device, comprising:

18. 18. The method for manufacturing an electronic device according to claim 17, comprising: a delay time from when the target is irradiated with the first pre-pulse laser beam to when the diffused target is irradiated with the second pre-pulse laser beam is 150 ns or more and 250 ns or less; A method for manufacturing electronic devices.

19. A method for manufacturing an electronic device, comprising: a chamber; a target supply unit that supplies a target into the chamber; a first laser device that generates a diffused target that is convex in a traveling direction of the first pre-pulse laser beam by irradiating the target with a first pre-pulse laser beam having a wavelength of 1 μm; a second laser device that generates a low-density diffused target by irradiating the diffused target with a second pre-pulse laser beam having a wavelength of 1 μm; a third laser device that generates extreme ultraviolet light by irradiating the low-density diffused target with a main pulse laser beam having a wavelength of 1 μm; and inspecting a mask for defects by irradiating the mask with the extreme ultraviolet light generated by the extreme ultraviolet light generating device, selecting a mask using the results of said testing; The pattern formed on the selected mask is transferred onto a photosensitive substrate by exposure. A method for manufacturing an electronic device, comprising:

20. 20. The method of manufacturing an electronic device according to claim 19, comprising: a delay time from when the target is irradiated with the first pre-pulse laser beam to when the diffused target is irradiated with the second pre-pulse laser beam is 150 ns or more and 250 ns or less; A method for manufacturing electronic devices.

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