Light-emitting unit

Abstract

The present invention accurately adjusts the film thickness of a liquid starting material.　A light-emitting unit according to one aspect of the present technology comprises a housing part, an accommodation part, a rotation body, a first film thickness adjustment mechanism, and a shield body. An energy beam can pass through the housing part. The accommodation part is disposed inside the housing part and can accommodate a liquid starting material. The rotation body is rotatable about a rotation axis in a direction intersecting a gravity direction, and has a first region which is immersed in the liquid starting material accommodated in the accommodation part, and a second region which is located downstream of the first region in the rotation direction of the rotation body, to which the liquid starting material adheres, and which includes an energy beam irradiation position. The first film thickness adjustment mechanism is disposed at a position upstream of the irradiation position, and adjusts the film thickness of the liquid starting material adhering to the second region to a first film thickness. The shield body is disposed between the first film thickness adjustment mechanism and the liquid surface of the liquid starting material accommodated in the accommodation part and between the second region and the housing part, and has an opposite surface facing the liquid surface in a vertical direction.

Description

Light-emitting unit

[0001] The present invention relates to a light-emitting unit that supplies plasma raw material that generates X-rays, extreme ultraviolet light, and the like.

[0002] Traditionally, X-rays have been used for medical, industrial, and research applications. In the medical field, X-rays are used for applications such as chest radiography, dental radiography, and CT (Computer Tomography). In the industrial field, X-rays are used for applications such as non-destructive testing to observe the interior of materials such as structures and welds, and non-destructive tomographic testing. In the research field, X-rays are used for applications such as X-ray diffraction to analyze the crystalline structure of materials, and X-ray spectroscopy (X-ray fluorescence analysis) to analyze the constituent elements of materials.

[0003] Extreme ultraviolet light (hereinafter also referred to as "EUV light") with a wavelength of 13.5 nm, which is in the soft X-ray region with a relatively long wavelength among X-rays, has recently been used as exposure light. Here, the base material of a mask for EUV lithography on which a fine pattern is formed is a reflective mirror having a laminated structure in which a multilayer film (e.g., molybdenum and silicon) for reflecting EUV light is provided on a substrate made of low-thermal expansion glass. An EUV mask is then constructed by patterning a material that absorbs radiation with a wavelength of 13.5 nm on the multilayer film.

[0004] Furthermore, the size of unacceptable defects in EUV masks is significantly smaller than that of conventional ArF masks, making them difficult to detect. Therefore, EUV mask inspection is typically performed using actinic inspection, which uses radiation with a wavelength that matches the working wavelength of lithography. For example, inspection using radiation with a wavelength of 13.5 nm makes it possible to detect defects with a resolution less than the wavelength.

[0005] Generally, EUV light source devices include a DPP (Discharge Produced Plasma) light source device, an LDP (Laser Assisted Discharge Produced Plasma) light source device, and an LPP (Laser Produced Plasma) light source device.

[0006] A DPP light source device applies a high voltage between electrodes to which a gaseous plasma raw material (discharge gas) containing EUV radiation species is supplied, generating a high-density, high-temperature plasma through discharge, and utilizes the extreme ultraviolet light emitted from the plasma.

[0007] An LDP light source device is an improved version of a DPP light source device, and for example, it supplies a liquid high-temperature plasma raw material (e.g., Sn (tin) or Li (lithium)) containing EUV radiating species to the surface of an electrode (discharge electrode) that generates a discharge, irradiates the raw material with an energy beam (e.g., an electron beam or a laser beam) to vaporize the raw material, and then generates high-temperature plasma by discharge.

[0008] An LPP light source device generates high-temperature plasma by exciting an EUV radiation species with a laser beam or the like. A known light source device of this type generates plasma by concentrating laser light on droplets of EUV radiation target material, such as tin (Sn) or lithium (Li), ejected in the form of tiny droplets.

[0009] Patent Document 1 proposes a method of obtaining radiation by supplying a plasma raw material for generating radiation such as X-rays or EUV to a rotor and irradiating the region of the rotor to which the plasma raw material has been supplied with an energy beam (laser beam). A cylindrical container with one open end is used as the rotor, and liquid plasma raw material is supplied to this container, and laser light is irradiated onto the inner peripheral surface of the container.

[0010] This method corresponds to the so-called LPP method, but instead of supplying liquid plasma raw material as droplets, it uses the centrifugal force of a rotor to supply the liquid plasma raw material to the area irradiated by the energy beam. Therefore, compared to methods such as focusing a laser beam on droplets, it is possible to obtain high-intensity radiation with a relatively simple configuration.

[0011] JP 2014-216286 A

[0012] In such a light source device, a film thickness adjustment mechanism is provided for the rotor to adjust the film thickness of the liquid precursor. The amount of liquid precursor scraped off from the rotor by the film thickness adjustment mechanism depends on (1) the film thickness of the liquid precursor adhering to the rotor and (2) the rotation speed of the rotor. As the rotation speed increases, the film thickness increases, and the amount of liquid precursor scraped off by the film thickness adjustment mechanism increases, eventually exceeding the amount that the film thickness adjustment mechanism can hold or discharge. This makes it impossible to control the film thickness of the liquid precursor to the desired thickness, resulting in unstable EUV light intensity.

[0013] Furthermore, as the rotation speed of the rotor increases, the liquid material begins to splash higher at the part of the rotor immersed in the liquid material that rises above the liquid surface, and if this splashing adheres to the rotor, it becomes difficult to adjust the film thickness using only one skimmer.

[0014] In view of the above circumstances, an object of the present invention is to provide a light-emitting unit that allows the thickness of a liquid raw material to be adjusted with high precision.

[0015] In order to achieve the above object, a light-emitting unit according to one aspect of the present technology is a light-emitting unit that generates radiation by converting a liquid raw material into plasma using irradiation of an energy beam, and includes a housing, a storage unit, a rotor, a first film thickness adjustment mechanism, and a shield. The housing is capable of passing the energy beam. The storage unit is disposed inside the housing and can store the liquid raw material. The rotor is rotatable about a rotation axis in a direction intersecting the direction of gravity, and has a first region immersed in the liquid raw material stored in the storage unit, and a second region downstream of the first region in the rotation direction of the rotor, to which the liquid raw material adheres, and which includes an irradiation position of the energy beam. The first film thickness adjustment mechanism is disposed upstream of the irradiation position and adjusts the film thickness of the liquid raw material adhered to the second region to a first film thickness. The shielding body is disposed between the first film thickness adjustment mechanism and the liquid surface of the liquid raw material contained in the container, and between the second region and the housing, and has an opposing surface that faces the liquid surface in the vertical direction.

[0016] In this light-emitting unit, the shield and the first film thickness adjustment mechanism are arranged in this order from the upstream side of the rotation of the rotor, thereby suppressing adhesion of the liquid source to the rotor and the like even at high rotation speeds, and allowing the film thickness to be adjusted with precision.

[0017] In order to achieve the above object, a light-emitting unit according to the present technology is a light-emitting unit that generates radiation by converting a liquid raw material into plasma using irradiation with an energy beam, and includes a container, the rotor, the first film thickness adjustment mechanism, and a second film thickness adjustment mechanism. The container is capable of containing the liquid raw material. The second film thickness adjustment mechanism is disposed upstream of the first film thickness adjustment mechanism and faces a first surface of the second region that includes the irradiation position, and adjusts the film thickness to a second film thickness that is thicker than the first film thickness.

[0018] In this light-emitting unit, the second film thickness adjustment mechanism and the first film thickness adjustment mechanism are arranged in this order from the upstream side of the rotation of the rotor, thereby reducing the liquid pressure acting on the second film thickness adjustment mechanism and the first film thickness adjustment mechanism due to the liquid source, and allowing the film thickness to be adjusted with precision.

[0019] The shielding body may include a second film thickness adjustment mechanism that is arranged upstream of the first film thickness adjustment mechanism, facing a first surface that is a surface of the second region that includes the irradiation position, and that adjusts the film thickness to a second film thickness that is thicker than the first film thickness.

[0020] The light-emitting unit may further include a housing portion through which the energy beam can pass. In this case, the container portion may be disposed inside the housing portion. The second film thickness adjustment mechanism may include a shielding body disposed between the first film thickness adjustment mechanism and the liquid surface of the liquid raw material contained in the container portion and between the second region and the housing portion, and having an opposing surface facing the liquid surface in the vertical direction.

[0021] The second region may be made up of the first surface, a second surface opposite to the first surface, and a side surface of the rotating body.

[0022] The shield and the second film thickness adjustment mechanism may be arranged to divide the rotor along the liquid surface when viewed from the direction of the rotation axis.

[0023] The shield and the second film thickness adjustment mechanism may be arranged along the liquid surface at a position upstream of the irradiation position in the rotation direction of the rotor when viewed from the direction of the rotation axis.

[0024] The shield may be disposed opposite the side surface.

[0025] The shield may be disposed opposite the second surface.

[0026] The shield and the second film thickness adjustment mechanism may be configured as a single member.

[0027] The shield and the second film thickness adjustment mechanism may have a plate-like shape.

[0028] The shield and the second film thickness adjustment mechanism may be formed of different members. In this case, the second film thickness adjustment mechanism may be disposed downstream of the shield.

[0029] The first film thickness adjustment mechanism may be disposed opposite the first surface, and may include a protrusion that protrudes toward the first surface and adjusts the film thickness to a first film thickness, and a holder that holds the liquid source adhered to the first surface.

[0030] The holding unit may have a discharge port provided opposite the first surface and configured to discharge the liquid source to the outside of the holding unit.

[0031] The light-emitting unit may further include a housing portion through which the energy beam can pass and in which a container portion is disposed inside. In this case, the light-emitting unit may further include a first member having an immersion portion immersed in the liquid source contained in the container portion and an exposure portion exposed from the liquid source contained in the container portion, and including the first film thickness adjustment mechanism, the second film thickness adjustment mechanism, and a shield disposed between the rotor and the housing portion.

[0032] The light-emitting unit may further include a housing portion through which the energy beam can pass and in which a container portion is disposed inside. In this case, the light-emitting unit may further include a second member exposed from the liquid raw material contained in the container portion, the second member including the first film thickness adjustment mechanism, the second film thickness adjustment mechanism, and a shield disposed between the rotor and the housing portion.

[0033] The first film thickness adjustment mechanism may have an inclined surface facing the shield.

[0034] The energy beam may be a laser beam.

[0035] The radiation may be extreme ultraviolet light or x-rays.

[0036] The liquid source may be tin, lithium, gadolinium, terbium, gallium, bismuth, indium, or an alloy containing at least one of these materials.

[0037] According to the present invention, adhesion of the liquid source to the rotating body or the like is suppressed even at high rotation speeds, and the film thickness is adjusted with precision. Furthermore, the liquid pressure acting on each of the first film thickness adjustment mechanism and the second film thickness adjustment mechanism due to the liquid source is reduced, and the film thickness is adjusted with precision. Note that the effects described here are not necessarily limited, and any of the effects described in this disclosure may be used.

[0038] FIG. 7 is a schematic diagram showing a configuration example of a light source device according to a first embodiment of the present invention. FIG. 8 is a schematic diagram showing a configuration example of a plasma generation mechanism. FIG. 9 is a top view of a plasma generation mechanism. FIG. 10 is a schematic diagram showing a configuration example of a plasma generation mechanism. FIG. 11 is a top view of a plasma generation mechanism. FIG. 12 is a schematic diagram showing a configuration example of a plasma generation mechanism. FIG. 13 is a schematic diagram showing a configuration example of a plasma generation mechanism. FIG. 14 is a cross-sectional view taken along line A-A in FIG. 7. FIG. 15 is a schematic diagram showing a configuration example of a plasma generation mechanism. FIG. 16 is a schematic diagram showing a configuration example of a block member. FIG. 17 is a schematic diagram showing a configuration example of a plasma generation mechanism.

[0039] Hereinafter, embodiments of the present technology will be described with reference to the drawings.

[0040] <First Embodiment> [Basic Configuration of Light Source Device] Fig. 1 is a schematic diagram showing an example of the configuration of a light source device according to a first embodiment of the present invention. The light source device 100 is an LPP-type light source device. In other words, the light source device 100 converts a plasma raw material 1 into plasma by irradiating it with an energy beam EB, and extracts radiation R. In this disclosure, radiation R includes light (electromagnetic waves) emitted from a plasma P, such as light in the soft X-ray region, such as EUV light, and higher-energy hard X-rays.

[0041] When EUV light is emitted as the radiation R, an EUV raw material is used as the plasma raw material 1. As raw materials for emitting EUV light, for example, liquid tin (Sn) or lithium (Li) is used. Sn and Li are solid at room temperature, but are used in a liquid state when irradiated with the energy beam EB. When X-rays are emitted as the radiation R, an X-ray raw material is used as the plasma raw material 1. The X-ray raw material is, for example, a metal that is liquid at room temperature, and examples of the X-ray raw material that can be used include gallium (Ga), a gallium alloy, and an Sn compound. The plasma raw material 1 corresponds to one embodiment of a liquid raw material according to the present technology.

[0042] FIG. 1 is a diagram showing a schematic cross section of the light source device 100 taken horizontally at a predetermined height from the installation surface, as viewed from above. In FIG. 1 , cross sections of portions that are not necessary for explaining the cross-sectional configuration, etc., are omitted to facilitate understanding of the configuration and operation of the light source device 100. Hereinafter, the X direction may be referred to as the left-right direction (the positive side of the X axis is the right side, and the negative side is the left side), the Y direction as the front-rear direction (the positive side of the Y axis is the front side, and the negative side is the rear side), and the Z direction as the height direction (the positive side of the Z axis is the upper side, and the negative side is the lower side). Of course, the application of the present technology is not limited to the orientation in which the light source device 100 is used.

[0043] The light source device 100 includes a housing 2, a vacuum chamber 3, an energy beam entrance chamber 4, a radiation exit chamber 5, a plasma generation mechanism 6, a control unit 7, and a raw material supply device 30. In Fig. 1, the raw material supply device 30 is schematically illustrated by a dashed frame.

[0044] 1, the housing 2 is configured so that its outer shape is roughly cubic. The shape of the housing 2 is not limited to a cube, and any three-dimensional shape may be used. The housing 2 has an exit hole 2a formed on the front surface, an entrance hole 2b formed on the right side surface, a through-hole 2c formed on the rear surface, and a through-hole 2d formed on the left side surface. The material of the housing 2 is not limited, and a metal housing may be used, for example.

[0045] In this embodiment, the emission axis EA of the radiation R is set to pass through the emission hole 2a on the front surface and extend in the Y direction (front-rear direction). The radiation R, such as X-rays or EUV light, is extracted along the emission axis EA and emitted forward from the emission hole 2a. In this embodiment, the incident axis IA of the energy beam EB is set to extend obliquely left toward the rear from the entrance hole 2b on the right surface. As shown in FIG. 1 , a beam source 8 that emits the energy beam EB is installed outside the housing 2. The beam source 8 is installed so that the energy beam EB enters the housing 2 along the incident axis IA. An electron beam or a laser beam can be used as the energy beam EB. The beam source 8 may be configured in any manner that can emit such an energy beam EB.

[0046] The light source device 100 is provided with a chamber section C including a plurality of chambers. Specifically, the chamber section C has a vacuum chamber 3, an energy beam incident chamber (hereinafter simply referred to as an incident chamber) 4, and a radiation exit chamber (hereinafter simply referred to as an exit chamber) 5. The vacuum chamber 3, the incident chamber 4, and the exit chamber 5 are spatially connected to one another. That is, the vacuum chamber 3 and the incident chamber 4 are connected to one another. Similarly, the vacuum chamber 3 and the exit chamber 5 are connected to one another.

[0047] The entrance chamber 4 is formed to be located on an entrance axis IA of the energy beam EB, and the exit chamber 5 is formed to be located on an exit axis EA of the radiation R. In addition, the vacuum chamber 3 is provided with a mechanism for generating plasma P.

[0048] In this embodiment, the chamber section C (vacuum chamber 3, entrance chamber 4, and exit chamber 5) is made up of the chamber main body 9, an outer protrusion 9a that protrudes forward from the front surface of the chamber main body 9, and two inner protrusions 9b and 9c that protrude inward from the inner peripheral surface of the chamber main body 9. Metal materials are used as the materials for the chamber main body 9, the outer protrusion 9a, and the two inner protrusions 9b and 9c that make up the chamber section C.

[0049] The chamber main body 9 is configured so that its outer shape is roughly a rectangular parallelepiped, and is disposed so that its front, rear, left, and right faces face the front, rear, left, and right faces of the housing 2. The chamber main body 9 is also disposed so that its right front corner between the front face and right face is located on the incident axis IA of the energy beam EB.

[0050] As shown in FIG. 1 , an emission hole 9d is formed in the front surface of the chamber main body 9. The emission hole 9d is formed at a position aligned with the emission hole 2a in the front surface of the housing 2 on the emission axis EA of the radiation R. An outer protrusion 9a is configured to protrude forward from the periphery of the emission hole 9d in the chamber main body 9. The outer protrusion 9a is configured to protrude further forward than the emission hole 2a in the housing 2 so as to be inscribed within the emission hole 2a. Furthermore, an inner protrusion 9b is configured to protrude inward from the periphery of the emission hole 9d on the interior side of the chamber main body 9. Note that the configuration of the inner protrusion 9b is not essential, and only the outer protrusion 9a may be provided in the chamber section C. The space surrounded by the outer protrusion 9a and the inner protrusion 9b functions as the emission chamber 5. The outer protrusion 9a and the inner protrusion 9b, which are members that constitute the emission chamber 5, may themselves be referred to as the emission chamber. The outer protrusion 9 a and the inner protrusion 9 b may be formed integrally with the chamber body 9 or may be formed separately and then connected to the chamber body 9 .

[0051] The exit chamber 5 is configured to have a cone shape with the exit axis EA of the radiation R as its central axis. The exit chamber 5 is configured so that, in the direction of the exit axis EA of the radiation R, the cross-sectional area is large in the center and becomes smaller toward the front and rear ends. In other words, the exit chamber 5 has a shape that narrows toward the front and rear ends. Furthermore, the exit chamber 5 is provided with openings (apertures) at the front and rear ends to allow the radiation R to pass through.

[0052] A utilization device such as a mask inspection device is connected to the front end of the extraction chamber 5 (the front end of the outer protrusion 9a). In the example shown in FIG. 1, an application chamber 10 is connected as a chamber forming part of the utilization device. The pressure inside the application chamber 10 may be atmospheric pressure. Furthermore, the inside of the application chamber 10 may be purged by introducing gas (e.g., inert gas) through a gas injection path as needed. Furthermore, the gas inside the application chamber 10 may be exhausted by exhaust means (not shown).

[0053] A filter film 11 is provided between the extraction chamber 5 and the application chamber 10 to physically separate the region where plasma P is generated from the application chamber 10. The filter film 11 is constructed with a structure that allows radiation to pass through, and prevents the plasma raw material 1 and debris that are scattered as plasma P is generated from entering the application chamber 10.

[0054] A collector (condensing mirror) 12 is disposed inside the exit chamber 5 to guide and condense the radiation R that has entered the exit chamber 5 into a utilization device (inside the application chamber 10). In Figure 1, the components of the radiation R that enter the exit chamber 5 and are condensed are indicated by hatching.

[0055] A shielding member (central obscuration) 13 is also disposed inside the exit chamber 5. The shielding member 13 is disposed on the exit axis EA of the radiation R so as to be aligned with the exit hole 9d of the chamber body 9, the exit hole 2a of the housing 2, and the filter film 11. In this embodiment, the shielding member 13 can block radiation components that are not collected by the collector 12. Note that the shielding member 13 does not necessarily have to be provided.

[0056] An entrance window 14 is formed in the front right corner of the chamber body 9. The entrance window 14 is formed at a position aligned with the entrance hole 2b on the right side of the housing 2 on the entrance axis IA of the energy beam EB. An inner protrusion 9c is formed inside the front right corner of the chamber body 9 so as to protrude from a position surrounding the entrance window 14 along the direction of the entrance axis IA of the energy beam EB. Of the internal space of the chamber body 9, the space surrounded by the inner protrusion 9c functions as the entrance chamber 4. The inner protrusion 9c and the front right corner of the chamber body 9 that constitute the entrance chamber 4 can also be referred to as the entrance chamber. The inner protrusion 9c may be formed integrally with the chamber body 9, or may be formed separately and then connected to the chamber body 9.

[0057] The incident chamber 4 is configured to have a cone shape with the incident axis IA of the energy beam EB as its central axis. The incident chamber 4 is configured so that its cross-sectional area decreases toward the inner end of the chamber body 9 in the direction of the incident axis IA of the energy beam EB. In other words, the incident chamber 4 has a shape that narrows toward the inner end. Furthermore, the incident chamber 4 has an opening (aperture) at its inner end that allows the energy beam EB to pass through.

[0058] A capture mechanism for capturing scattered plasma raw material 1 and debris is placed inside the injection chamber 4. In the example shown in Figure 1, the capture mechanism is a rotary window 15, which is a plate-shaped rotating member that transmits the energy beam EB and captures the plasma raw material 1 and debris. By rotating the rotary window 15, the effective area of ​​the beam transmission region of the rotary window 15 increases, making it possible to reduce the frequency with which the rotary window 15 is replaced.

[0059] 1, the extraction chamber 5 and the incidence chamber 4 are provided with gas injection paths 16a and 16b, respectively, and gas is supplied from a gas supply device (not shown) into the extraction chamber 5 and the incidence chamber 4. A gas having a high transmittance to the radiation R is supplied to the extraction chamber 5. A gas having a high transmittance to the energy beam EB is supplied to the incidence chamber 4.

[0060] The gases supplied to the extraction chamber 5 and the incidence chamber 4 may be the same or different. For example, argon or helium can be used as gases that have high transmittance for both the energy beam EB and the radiation R. There are no other limitations on the type of gas supplied to the extraction chamber 5 and the incidence chamber 4. By supplying gas, the internal pressure of the extraction chamber 5 and the incidence chamber 4 can be set higher than the internal pressure of the vacuum chamber 3, thereby making it possible to suppress the intrusion of debris and the like.

[0061] Of the internal space of the chamber main body 9, the space excluding the internal space of the inner protrusion 9b that functions as the emission chamber 5 and the internal space of the inner protrusion 9c that functions as the incidence chamber 4 functions as the vacuum chamber 3. The part that constitutes the vacuum chamber 3 itself can also be called the vacuum chamber.

[0062] 1 , the chamber main body 9 has a portion that protrudes from the housing 2 to the outside through a through-hole 2d on the left side surface of the housing 2, and its tip is connected to an exhaust pump 17. The specific configuration of the exhaust pump 17 is not limited, and any pump such as a vacuum pump may be used. The exhaust pump 17 evacuates the vacuum chamber 3, reducing the pressure in the vacuum chamber 3. This suppresses attenuation of the radiation R generated in the vacuum chamber 3. The inside of the vacuum chamber 3 need only be a reduced pressure atmosphere relative to the entrance chamber 4 and the exit chamber 5, and does not necessarily have to be a vacuum atmosphere. An inert gas may also be supplied into the vacuum chamber 3.

[0063] In this embodiment, a gas nozzle 18 is installed so as to extend in the left-right direction toward the region between the incident axis IA and the exit axis EA. The gas nozzle 18 is installed on the right side surface of the chamber body 9 via a seal member or the like. The gas nozzle 18 is connected to a gas supply device (not shown) and supplies gas into the chamber body 9. The configuration of the gas nozzle 18 is not essential, and gas may be supplied without passing through the gas nozzle. In the example shown in FIG. 1 , gas is sprayed from the gas nozzle 18 from the right side of the region between the incident axis IA and the exit axis EA toward the left side along the left-right direction. This makes it possible to move debris emitted from the plasma P in a direction away from the incident axis IA and the exit axis EA.

[0064] The plasma generation mechanism 6 is a mechanism for generating plasma P within the vacuum chamber 3 and emitting radiation R (X-rays, EUV light). The plasma generation mechanism 6 includes a disk-shaped rotor 20 for supplying raw material, and a raw material container 21 for accommodating liquid plasma raw material 1. The rotor 20 and raw material container 21 are disposed inside the vacuum chamber 3. The plasma generation mechanism 6 corresponds to one embodiment of a light-emitting unit according to the present technology that converts the plasma raw material 1 into plasma by irradiating it with an energy beam EB, thereby generating radiation.

[0065] 1, an energy beam EB is incident on a disk-shaped rotating body 20. The rotating body 20 is disposed in the vacuum chamber 3 so that the irradiation position I of the energy beam EB is located at the intersection of an incident axis IA and an exit axis EA. The shape of the rotating body is not limited to a disk shape, and a polygonal rotating body, for example, may be used.

[0066] The raw material container 21 is provided so that the rotor 20 is immersed therein, and liquid plasma raw material 1 is supplied to the rotor 20. For example, the rotor 20 is rotatably held while immersed in the liquid plasma raw material 1 in the raw material container 21, and the plasma raw material 1 adheres to the surface of the rotor 20. As the rotor 20 rotates in this state, the plasma raw material 1 is supplied to the irradiation position I of the rotor 20. Then, an energy beam EB is incident on the irradiation position I of the rotor 20, and plasma P is generated.

[0067] In this way, the raw material container 21 is provided within the vacuum chamber 3, stores the liquid plasma raw material 1, and supplies the liquid plasma raw material 1 to the irradiation position I of the energy beam EB. The raw material container 21 corresponds to one embodiment of a storage unit capable of storing a liquid raw material according to the present technology. The other configurations of the plasma generation mechanism 6 will be described in detail later.

[0068] The control unit 7 controls the operation of each component of the light source device 100. For example, the control unit 7 controls the operation of the beam source 8 and the exhaust pump 17. The control unit 7 also controls the operation of various motors, the raw material supply device 30, and the like, which will be described later. The control unit 7 has hardware circuits necessary for a computer, such as a CPU and memory (RAM, ROM). The CPU loads a control program stored in the memory into the RAM and executes it, thereby performing various processes. The control unit 7 may be, for example, a programmable logic device (PLD) such as a field programmable gate array (FPGA), or another device such as an application specific integrated circuit (ASIC). While the control unit 7 is schematically illustrated as a functional block in FIG. 1 , the location of the control unit 7 may be designed as desired.

[0069] 1 , in this embodiment, a radiological diagnostic unit 19 is configured in a region spatially connected to the vacuum chamber 3 on the front side of the chamber main body 9. The radiological diagnostic unit 19 is configured at a position where radiation R emitted in a direction different from the emission axis EA of the radiation R is incident. The radiological diagnostic unit 19 measures the state of the radiation R from the plasma P. Here, the state of the radiation R refers to the physical state of the radiation R, such as the intensity, wavelength, and spectrum of the radiation R. For example, the radiological diagnostic unit 19 is configured by a detector that detects the presence or absence of radiation R and a measuring device that measures the radiation output. The measurement results by the radiological diagnostic unit 19 are used for diagnosing the radiation R and for controlling the operation of the raw material supply device 30, which will be described below.

[0070] The raw material supply device 30 supplies the plasma raw material 1 into the raw material container 21. The specific configuration of the raw material supply device 30 and the timing at which the raw material supply device 30 supplies the plasma raw material 1 are not limited.

[0071] [Plasma Generation Mechanism] Fig. 2 is a schematic diagram showing an example of the configuration of the plasma generation mechanism 6. Fig. 3 is a top view of the plasma generation mechanism 6. Fig. 2 shows the plasma generation mechanism 6 as viewed from the top (positive side in the Y direction) in Fig. 1. It also shows a state in which the energy beam EB is emitted by the beam source 8. Fig. 3 shows the plasma generation mechanism 6 as viewed from the front side in Fig. 1 and from the top (positive side in the Z direction) in Fig. 2.

[0072] The plasma generation mechanism 6 includes a rotor 20, a raw material container 21, a cover structure 40, and skimmers 22a and 22b. The raw material container 21 is shown by a dashed line in Figures 2 and 3.

[0073] The rotor 20 has a disk portion 44 and a shaft portion 45. The disk portion 44 is disk-shaped and has a surface 41, a back surface 42, and a side surface 39. The surface 41 is the front surface in FIG. 2 and the lower surface in FIG. 3. The back surface 42 is the rear surface in FIG. 2 and the upper surface in FIG. 3. The side surface 39 is the left and right surface in FIGS. 2 and 3. In FIG. 2, a portion of the lower side of the rotor 20 is immersed in the plasma raw material 1 contained in the source material container 21. Therefore, a portion of the lower side of the rotor's surface 41 is a region immersed in the plasma raw material 1. Hereinafter, this region will be referred to as an immersion region 43. For example, if the source material container 21 contains a large amount of plasma raw material 1, most of the rotor's surface 41 will be immersed, and the area of ​​the immersion region 43 will be large. The shape of the immersion region 43 can vary depending on the size and shape of the rotor 20 and the source material container 21. The immersion region 43 corresponds to an embodiment of a first region according to the present technology. Similarly, a part of the lower side of the rear surface 42 and a part of the lower side of the side surface 39 also serve as the immersion region 43.

[0074] The shaft portion 45 has an elongated cylindrical shape and is disposed so that its circular surface abuts against the center of the back surface 42 of the rotating body 20. In this embodiment, the rotating body 20 is configured to be rotatable about a predetermined rotation axis. Specifically, the rotating body 20 rotates about a rotation axis H that is parallel to the Y direction. The rotation axis H is indicated by a dashed line in FIG. 3 .

[0075] The shaft portion 45 is disposed so as to extend along the rotation axis H. That is, the shaft portion 45 is disposed parallel to the Y direction. Therefore, the disk portion 44 and the shaft portion 45 rotate integrally with the rotation axis H as the central axis. As shown in FIG. 2 , in this example, the direction of rotation is counterclockwise when viewed from the positive side of the Y direction, but the direction of rotation may also be clockwise.

[0076] Furthermore, in this embodiment, the direction of the rotation axis H is a direction that intersects with the direction of gravity. Specifically, the direction of the rotation axis H is the Y direction, which is a direction that intersects with the direction of gravity (Z direction). This is not limited to this, and for example, a direction that is obliquely inclined with respect to the direction of gravity is also included in the direction that intersects with the direction of gravity. Therefore, not only the case where the rotating body 20 rotates while being arranged parallel to the XZ plane as in this example, but also the case where the rotating body 20 rotates while being arranged obliquely with respect to the XZ plane are included in the scope of the present technology. Alternatively, the direction of the rotation axis H may be any direction that intersects with the direction of gravity.

[0077] The portion of the surface 41 of the rotor 20 above the immersion region 43 is the region where the plasma raw material 1 adheres. Specifically, the rotation of the rotor 20 lifts the plasma raw material 1, and the plasma raw material 1 is supported by the region of the surface 41 that is not immersed in the plasma raw material 1. Hereinafter, this region will be referred to as the adhesion region 46. In Figure 2, the portion where the plasma raw material 1 adheres is schematically shown in dark gray and light gray. In this way, the adhesion region 46 is a ring-shaped region of the surface 41 above the immersion region 43. The adhesion region 46 can also be said to be a carrier that supports the plasma raw material 1. The adhesion region 46 corresponds to one embodiment of the second region according to the present technology.

[0078] Similarly, the upper side of the back surface 42 and the upper side of the side surface 39 also become the attachment region 46. Therefore, the attachment region 46 is made up of the front surface 41, the back surface 42 which is the surface opposite to the front surface 41, and the side surface 39. The front surface 41 corresponds to an embodiment of a first surface according to the present technology. The back surface 42 corresponds to an embodiment of a second surface according to the present technology.

[0079] The cover structure 40 is disk-shaped and has disk portions 47 and 48 and a side portion 49. The disk portions 47 and 48 are circular flat plates that are parallel to the XZ plane and arranged with their centers positioned on the rotation axis H. The disk portion 47 is arranged on the front side in FIG. 2 , and the disk portion 48 is arranged on the back side, facing each other. Note that the disk portion 47 on the front side is not shown in FIG. 2 so that the internal mechanism of the cover structure 40 can be seen. The side portion 49 has a ring shape when viewed from the front side in FIG. 2 , and is formed between the disk portions 47 and 48.

[0080] The cover structure 40 also has an internal space S surrounded by the disk portions 47 and 48 and the side portion 49. That is, the internal space S is also a disk-shaped space. In this embodiment, the rotating body 20 is rotatably disposed in the internal space S. Specifically, as shown in FIG. 2 , the rotating body 20 is housed so that the circular disk portion 44 appears to be surrounded by the larger circular cover structure 40.

[0081] This allows the rotating body 20 to rotate smoothly in the internal space S. For example, depending on the shape of the cover structure 40, the rotating body 20 may collide with the disk portions 47 and 48 or the side portions 49 of the cover structure 40 during rotation, which may impede rotation. In this example, the shapes of the cover structure 40 and the internal space S are appropriately designed, so such impediment to rotation does not occur. The specific shapes of the cover structure 40 and the internal space S are not limited, and any shape that can rotatably accommodate the rotating body 20 may be adopted.

[0082] The internal space S also contains a raw material container 21. For example, the raw material container 21 is placed in the lower part of the internal space S, and the lower part of the rotor 20 is immersed in the plasma raw material 1 contained in the raw material container 21. The raw material container 21 may be placed in any position that does not interfere with the rotation of the rotor 20.

[0083] An opening (not shown) is provided in the front-side disk portion 47. The energy beam EB emitted from the beam source 8 enters the internal space S through the opening and is irradiated onto the surface 41 of the disk portion 44. 2 and 3 schematically illustrate the portion of the optical path of the energy beam EB up to the surface 41. An irradiation position I is also schematically illustrated. Alternatively, for example, an opening may be provided in the side portion 49, and the energy beam EB may enter the internal space S from the side. The specific shape and size of the opening are not limited.

[0084] 2 , the energy beam EB is irradiated at the 9 o'clock position of the surface 41. In this embodiment, the positions of the opening and the beam source 8 are appropriately adjusted so that the irradiation position I is located on the adhesion region 46 of the surface 41. In other words, for example, the energy beam EB is not irradiated onto the immersion region 43. In this way, the adhesion region 46 is an area that includes the irradiation position I.

[0085] The specific position of the irradiation position I is not limited, and the energy beam EB may be irradiated to any position on the attachment region 46 within a range in which the present technology can be realized. In addition, although the irradiation position I is schematically illustrated as a point in Figure 2 and the like, the energy beam EB may be irradiated over a wide range on the attachment region 46, and the irradiation position I may become a wide-ranging irradiation surface.

[0086] Irradiation with the energy beam EB generates plasma P at the irradiation position I, and radiation R is emitted. The radiation R is emitted in all directions on the front side of FIG. 2 , although the intensity varies depending on the radiation angle. The radiation R is extracted, for example, from an opening (which may be the same as or different from the opening through which the energy beam EB enters) provided in the disk portion 47 on the front side of the cover structure 40, and is then utilized by a utilization device.

[0087] A circular through-hole 51 is provided in the disk portion 48 on the back side. The through-hole 51 is provided in the center of the disk portion 48. As shown in Fig. 3, the shaft portion 45 of the rotating body 20 passes through the through-hole 51, and the upper end portion is exposed from the cover structure 40. The upper end portion is connected to a motor or the like, and the rotation of the rotating body 20 is achieved by the control unit 7 controlling the drive of the motor or the like.

[0088] The position and shape of the through-hole 51 are not limited, and any configuration may be adopted as long as it allows rotation of the rotor 20. Furthermore, for example, a mechanism such as a mechanical seal may be provided between the shaft portion 45 and the through-hole 51 as appropriate. This allows the rotor 20 to rotate smoothly while maintaining the air pressure in the internal space S. The cover structure 40 corresponds to one embodiment of a housing portion according to the present technology that allows the energy beam EB to pass through.

[0089] [Skimmer] The skimmer 22a is disposed at a position upstream of the irradiation position I in the rotation direction of the rotor 20. In this embodiment, the boundary between the upstream and downstream sides of the rotation is defined as the 6 o'clock position. Because the rotation direction of the rotor 20 is counterclockwise, the upstream side of the irradiation position I (9 o'clock position) is the 9 o'clock to 12 o'clock (midnight) and midnight to 6 o'clock positions, and the downstream side is the 6 o'clock to 9 o'clock positions.

[0090] 2, the skimmer 22a is disposed between the 1 o'clock and 2 o'clock positions on the surface 41 of the disk portion 44. Therefore, the skimmer 22a is disposed upstream of the irradiation position I. The skimmer 22a may also be disposed at any other position upstream of the irradiation position I, such as the 3 o'clock position. Similarly, the attachment region 46 can be said to be downstream of the immersion region 43.

[0091] The skimmer 22a has, for example, a rod shape and is disposed at a predetermined distance from the surface 41 of the disk portion 44. By appropriately setting this distance, it is possible to adjust the film thickness of the plasma raw material 1 after it has passed through the skimmer 22a to a desired value. The skimmer 22a is fixed to the cover structure 40, for example. The skimmer 22a may be fixed via an elastic body such as a spring. Furthermore, a protrusion may be formed on the surface of the disk portion 44 that faces the surface 41. There are no other limitations on the specific shape of the skimmer 22a. The skimmer 22a corresponds to one embodiment of the first film thickness adjustment mechanism according to the present technology.

[0092] The skimmer 22b has a plate-like shape. Specifically, as shown in Fig. 3, the skimmer 22b has an upper surface 35 shaped like a rectangular frame with one side removed. The skimmer 22b also has a lower surface 36 of the same shape on the opposite side (the far side in Fig. 3), and is disposed so that the upper surface 35 and the lower surface 36 are parallel to the XY plane. The skimmer 22b is fixed to the cover structure 40, for example.

[0093] Skimmer 22b is disposed below skimmer 22a, between skimmer 22a and the liquid surface of the plasma raw material 1. Specifically, as shown in Fig. 2, skimmer 22b is disposed so that, from top to bottom, it is skimmer 22a, skimmer 22b, and the liquid surface. In other words, it can be said that skimmer 22b is disposed upstream of skimmer 22a. Skimmer 22b is also disposed between attachment region 46 and cover structure 40. Specifically, as shown in Fig. 3, skimmer 22b is disposed between disk portion 44 and cover structure 40 (disk portion 47 and side portion 49).

[0094] Skimmer 22b is also placed opposite surface 41 of disk portion 44. Specifically, skimmer 22b is placed at a predetermined distance from surface 41. By appropriately designing this distance, it is possible to adjust the film thickness of plasma raw material 1 after it has passed through skimmer 22b to a desired value. Similarly, skimmer 22b is also placed opposite side surface 39 of the disk portion.

[0095] Skimmer 22b also has a surface that faces the liquid surface of plasma raw material 1 in the vertical direction. Specifically, the facing surface is bottom surface 36 shown in FIG.

[0096] Furthermore, skimmer 22b is positioned so as to divide rotor 20 along the liquid surface of plasma raw material 1 when viewed from the direction of rotation axis H. Specifically, Figure 2 corresponds to the state of plasma generation mechanism 6 when viewed from the direction of rotation axis H (Y direction), and skimmer 22b extending in the horizontal direction (X direction) makes rotor 20 appear to be divided into upper and lower halves.

[0097] The specific shape of the skimmer 22b is not limited. For example, the skimmer 22b may have a shape other than a plate shape, such as a rod shape. A protrusion may be formed on the surface of the disk portion 44 facing the surface 41. Furthermore, the specific arrangement of the skimmer 22b is not limited. For example, an arrangement in which the upper surface 35 and the lower surface 36 are inclined with respect to the XY plane may be adopted as long as the present technology is feasible. The skimmer 22b corresponds to an embodiment of the shield and second film thickness adjustment mechanism according to the present technology.

[0098] The rotor 20, raw material container 21, cover structure 40, and skimmers 22a and 22b are made of a rigid material such as metal. Alternatively, a material with low reactivity with the plasma raw material 1, energy beam EB, and radiation R may be used as appropriate to prevent deterioration due to reaction with these. Other specific configurations are not limited.

[0099] 2, the areas where the plasma raw material 1 has a film thickness of A are shown in light gray, the areas where the film thickness is B are shown in medium gray, and the areas where the film thickness is C are shown in dark gray.

[0100] As shown in Figure 2, the film thickness of the area of ​​the surface 41 of the disk part 44 where the plasma raw material 1 has just emerged from the liquid surface is C. Film thickness C can take on various values ​​depending on the rotation speed of the rotor 20, etc. For example, when the rotation speed is fast, a large amount of the plasma raw material 1 is lifted up by the disk part 44, so film thickness C tends to be relatively thick. On the other hand, when the rotation speed is slow, film thickness C tends to be relatively thin.

[0101] In this embodiment, the skimmer 22b adjusts the film thickness of the plasma raw material 1 to a predetermined value B. Specifically, the skimmer 22b is positioned so that the distance between the skimmer 22b and the surface 41 of the disk portion 44 is equal to the film thickness B. As a result, if the film thickness C before passing through the skimmer 22b is greater than the distance between the skimmer 22b and the surface 41, the plasma raw material 1 that cannot pass between the skimmer 22b and the surface 41 is scraped off by the skimmer 22b, and after passing through, the plasma raw material 1 adheres to the surface 41 at the film thickness B.

[0102] Furthermore, the skimmer 22a adjusts the film thickness to a predetermined value A. Specifically, the skimmer 22a is positioned so that the distance between the skimmer 22a and the surface 41 is equal to the film thickness A. In this embodiment, the film thickness B is greater than the film thickness A. That is, the plasma raw material 1 that cannot pass between the skimmer 22a and the surface 41 is scraped off by the skimmer 22a, and after passing through, the plasma raw material 1 adheres to the surface 41 with the film thickness A.

[0103] As described above, in this embodiment, the film thickness is C at the portion just emerging from the liquid surface, but the film thickness is adjusted to B by skimmer 22b, and then to A by skimmer 22a, so that the film thickness is adjusted in two stages. The film thickness A after adjustment may be any value, and is set taking into consideration, for example, the intensity of the energy beam EB and the required intensity of radiation R. Similarly, the film thickness B may be any value greater than the film thickness A. For example, an intermediate value between the film thickness A and the expected film thickness C is set as the film thickness B. The film thickness A corresponds to an embodiment of a first film thickness according to the present technology. The film thickness B corresponds to an embodiment of a second film thickness according to the present technology, which is thicker than the first film thickness.

[0104] [Shielding of Splash] As the disk part 44 rotates, splashes occur on the liquid surface of the plasma raw material 1. Splashes occur most noticeably where the disk part 44 exits the plasma raw material 1, i.e., on the right side of Figure 2, and the faster the rotation speed, the more plasma raw material 1 splashes, and the faster it splashes. In this embodiment, splashes are shielded by the skimmer 22b.

[0105] The plasma raw material 1 is scattered mainly upward from the liquid surface. Here, because skimmer 22b has a lower surface 36 facing the liquid surface, the scattered plasma raw material 1 collides with lower surface 36. The colliding plasma raw material 1 either adheres to lower surface 36 or falls to the lower side and returns to raw material container 21, but in either case it does not scatter above skimmer 22b. In this way, skimmer 22b shields the liquid from splashing, preventing its effects from reaching areas above skimmer 22b.

[0106] In this embodiment, the member having the function of blocking liquid splashes (shielding body) and the member having the function of adjusting the film thickness (second film thickness adjustment mechanism) are configured as a single member (skimmer 22b). Specifically, the lower surface 36 of skimmer 22b functions as the shielding body, and the surface facing the surface 41 of disk portion 44 of rotor 20 functions as the second film thickness adjustment mechanism.

[0107] [Embodiment of Film Thickness Adjustment Mechanism + Film Thickness Adjustment Mechanism] In the example shown in FIG. 2, the skimmer 22a has the function of a film thickness adjustment mechanism, and the skimmer 22b has the function of a film thickness adjustment mechanism and a shield. That is, the skimmer 22b as a whole has the functions of a two-stage film thickness adjustment mechanism and a shield. This is not limited to this, and the skimmer 22b may not have the function of a shield and may only have the function of a film thickness adjustment mechanism. That is, the skimmer 22b may not have the function of a shield and may only have the function of a two-stage film thickness adjustment mechanism. In this case, the skimmer 22a corresponds to an embodiment of a first film thickness adjustment mechanism according to the present technology. The skimmer 22b corresponds to an embodiment of a second film thickness adjustment mechanism according to the present technology.

[0108] [Embodiment of Film Thickness Adjustment Mechanism + Shield] The skimmer 22b may not have the function of a film thickness adjustment mechanism, but may have only the function of a shield. That is, the skimmer 22a may have only the functions of a single film thickness adjustment mechanism and a shield as a whole. In this case, the skimmer 22a corresponds to an embodiment of the first film thickness adjustment mechanism according to the present technology. The skimmer 22b also corresponds to an embodiment of the shield according to the present technology.

[0109] As described above, in the plasma generation mechanism 6 according to this embodiment, the skimmers 22b and 22a are arranged in this order from the upstream side of the rotation of the rotor 20. This reduces the liquid pressure acting on each of the skimmers 22b and 22a due to the plasma raw material 1, allowing the film thickness to be adjusted with precision.

[0110] The rotating body is slightly eccentric. Also, there may be variations in thickness depending on the location. Therefore, in order to maintain a constant thickness of the liquid material applied to the rotating body, the skimmer is supported by an elastic body and moves slightly to accommodate these variations. However, as the rotation speed of the rotating body increases, the amount of liquid material adhering to the rotating body increases. This increases the amount of liquid material removed by the skimmer when adjusting the film thickness, and the skimmer is subjected to a large liquid pressure. If the liquid pressure exceeds the elastic force of the elastic body supporting the skimmer, it becomes difficult to obtain the desired film thickness.

[0111] In this embodiment, the film thickness is adjusted in two stages by the two skimmers 22a and 22b, so the amount of liquid material removed by each skimmer is smaller than when the film thickness is adjusted by a single skimmer. Therefore, the liquid pressure that each skimmer receives is also smaller. This makes it less likely for the skimmers to stack, even at high rotation speeds, and allows the film thickness to be adjusted with precision.

[0112] Furthermore, in the plasma generation mechanism 6 according to this embodiment, the skimmer 22b has the function of blocking liquid splashes, which prevents the liquid source from adhering to the rotating body and the like even at high rotation speeds, allowing the film thickness to be adjusted with precision.

[0113] As the rotation speed of the rotor increases, the liquid raw material begins to splash higher from the part of the rotor that rises above the liquid surface. If this material adheres to the rotor, the film thickness at that point will fluctuate significantly, making it difficult to adjust the film thickness. Furthermore, if the splashed liquid raw material adheres to undesirable parts of the plasma generation mechanism, it can lead to internal contamination.

[0114] In this embodiment, the skimmer 22b blocks splashing, thereby suppressing splashing on the portion of the rotor 20 above the skimmer 22b. Furthermore, the plasma raw material 1 scraped off by the upper skimmer 22a is received by the skimmer 22b, so splashing is less likely to occur than if the plasma raw material 1 were to fall directly into the liquid. This suppresses fluctuations in film thickness, allowing the film thickness to be adjusted with precision. Contamination of the various mechanisms of the plasma generation mechanism 6 is also suppressed.

[0115] In this embodiment, the skimmer 22b is positioned so as to divide the rotor 20 when viewed from the direction of the rotation axis H. This allows the skimmer 22b to be positioned stably. It also makes it possible to shield the liquid from splashing at the part of the rotor 20 where it enters the plasma raw material 1 (the left side of Figure 2).

[0116] In this embodiment, the skimmer 22b is disposed facing the side surface 39 of the rotor 20. This also blocks liquid splashes near the side surface 39, making it possible to further suppress contamination of the plasma generation mechanism 6. Note that the skimmer 22b may not face the side surface 39, but may face only the surface 41. In this case, it is possible to realize the plasma generation mechanism 6 with a simple configuration.

[0117] In this embodiment, the skimmer 22b is configured to have a plate-like shape, which further suppresses contamination of the plasma generating mechanism 6 and allows for accurate adjustment of the film thickness.

[0118] In this embodiment, the shield and the second film thickness adjustment mechanism are configured as a single member, which makes it possible to realize the plasma generation mechanism 6 with a simple configuration.

[0119] Second Embodiment A more detailed embodiment of the plasma generation mechanism 6 according to the present technology will be described as a second embodiment. In the following description, the description of the same parts as those in the configuration and operation of the plasma generation mechanism 6 described in the above embodiment will be omitted or simplified.

[0120] [Variations of the Lower Skimmer] Figure 4 is a schematic diagram showing an example of the configuration of the plasma generation mechanism 6. Figure 5 is a top view of the plasma generation mechanism 6. The configuration of this example is almost the same as the configuration of Figure 2, but the shape of the skimmer 22b is different. In this example, the upper surface 35 and the lower surface 36 of the skimmer 22b are L-shaped. Furthermore, the skimmer 22b is arranged so as to face only the right half of the surface 41 of the disk portion 44 and only the right side surface 39. In other words, the skimmer 22b of this example has the shape of the right half of the skimmer 22b in Figure 2 when cut in center, and does not have a portion facing the left half of the surface 41 of the disk portion 44 or the left side surface 39.

[0121] When viewed from the direction of the rotation axis H, the skimmer 22b is disposed along the liquid surface at a position upstream of the irradiation position I in the rotation direction of the rotor 20. Specifically, the irradiation position I is in the 9 o'clock direction, and the skimmer 22b is disposed between the 4 o'clock position and the 6 o'clock position. On the other hand, the skimmer 22b is not disposed at a position downstream of the irradiation position I (the 6 o'clock to 9 o'clock positions at the bottom left of FIG. 2).

[0122] There is no need to adjust the film thickness downstream of irradiation position I, and splashing is relatively unlikely to occur from the liquid surface on the left side. Therefore, even if the left half of skimmer 22b in Figure 2 is omitted, there is no significant effect on the operation of plasma generation mechanism 6. By configuring skimmer 22b with only the right half as in this example, it is possible to realize plasma generation mechanism 6 with a simple configuration.

[0123] 6 is a schematic diagram showing an example of the configuration of the plasma generation mechanism 6. In this example, the skimmer 22b does not function as a shield, but only functions as a film thickness adjustment mechanism. Instead, a cover member 60 is provided that functions as a shield. The shape of the cover member 60 is not limited, and it can be configured to have a shape that allows the lower surface to block liquid splashes, for example.

[0124] The shield and the second film thickness adjustment mechanism are composed of different members, and the second film thickness adjustment mechanism is disposed above the shield. In other words, it can be said that the second film thickness adjustment mechanism is disposed downstream of the shield. Specifically, the cover member 60 corresponds to the shield, and the skimmer 22b corresponds to the second film thickness adjustment mechanism. As shown in FIG. 6 , the skimmer 22b is disposed above the cover member 60.

[0125] Depending on the arrangement of other mechanisms in the plasma generation mechanism 6, it may be advantageous to separate the cover member 60 from the skimmer 22b. Furthermore, by arranging the skimmer 22b above the cover member 60, it becomes possible to first prevent liquid splashing with the cover member 60 before adjusting the film thickness, thereby adjusting the film thickness with even greater precision.

[0126] In addition, when the cover member 60 and the skimmer 22b are separate, a configuration in which only the cover member 60 spans left and right, a configuration in which only the skimmer 22b spans left and right, or a configuration in which both the cover member 60 and the skimmer 22b span left and right may be adopted.

[0127] <Third embodiment> [Variations of upper skimmer] Fig. 7 is a schematic diagram showing a configuration example of the plasma generation mechanism 6. Fig. 8 is a cross-sectional view taken along line A-A in Fig. 7. Fig. 8 shows the cross-section taken along line A-A in Fig. 7 as viewed from the left side (positive side in the X direction).

[0128] The configuration of this example is similar to that of Figure 2, but the shape of the skimmer 22a is different. In this example, the skimmer 22a is composed of a buffer 64 and an edge 65. The buffer 64 has a rectangular plate shape. As shown in Figure 7, the buffer 64 has a rectangular surface consisting of a lower side parallel to the X direction, a right side parallel to the Z direction, a left side parallel to approximately the 1 o'clock direction, and an upper side parallel to approximately the 10 o'clock direction, and is connected to the cover structure 40 so that this surface is parallel to the X and Z directions. Of course, the specific shape and connection form of the buffer 64 are not limited.

[0129] The edge 65 is a protrusion formed on the inner surface (negative surface in the Y direction) of the buffer 64, and protrudes toward the surface 41 of the disk portion 44. In other words, the edge 65 protrudes toward the negative side in the Y direction (the far side in FIG. 7). In FIG. 7, the edge 65 is schematically illustrated by a dashed line. In this way, the skimmer 22a (the buffer 64 and the edge 65) is disposed so as to face the surface 41 as a whole.

[0130] In this embodiment, the buffer 64 holds the plasma raw material 1 adhered to the surface 41. The edge 65 adjusts the film thickness. Figure 8 shows, in gray, a schematic representation of the plasma raw material 1 adhered to the surface 41 of the disk 44 at a predetermined film thickness. As the disk 44 rotates, the plasma raw material 1 adhered to the surface 41 moves toward the top of Figure 8. Specifically, the plasma raw material 1 first penetrates between the surface 41 and the buffer 64 from below. Eventually, the plasma raw material 1 reaches the edge 65, and the portion of the plasma raw material 1 that cannot pass between the surface 41 and the edge 65 is scraped off by the edge 65. Meanwhile, the plasma raw material 1 that passes between the surface 41 and the edge 65 moves above the edge 65, adhering to the surface 41 at a predetermined film thickness (indicated by the arrow in Figure 8). In this way, the film thickness is adjusted only by the edge 65, not by the entire skimmer 22a. This allows for more precise film thickness adjustment.

[0131] The plasma raw material 1 scraped off by the edge 65 is discharged mainly to the right of the skimmer 22a, as shown in Figure 7. In this example, the edge 65 is configured to have a downward slope on the left side. If the plasma raw material 1 is discharged to the left, the centrifugal force of the rotation may cause the discharged plasma raw material 1 to return to the adjusted film thickness, which could result in fluctuations in the film thickness. By configuring it as in this example, the plasma raw material 1 is less likely to be discharged to the left, making it possible to suppress the effect on the film thickness. Of course, the specific shape of the edge 65 is not limited.

[0132] Furthermore, a portion of the plasma raw material 1 scraped off by the edge 65 is not discharged from the skimmer 22a, but is retained between the surface 41 and the buffer 64. In other words, a certain amount of plasma raw material 1 remains accumulated in the buffer 64.

[0133] If the film thickness before passing over edge 65 is greater than the distance between surface 41 and edge 65, the film thickness is adjusted and reduced. On the other hand, there may be cases where the film thickness before passing over edge 65 is already smaller than the distance between surface 41 and edge 65, and the film thickness is not adjusted. In other words, in such cases, the film thickness after adjustment will be smaller than the desired film thickness. In this example, because buffer 64 is provided, even in such cases, the plasma raw material 1 accumulated in buffer 64 flows between surface 41 and edge 65, and the film thickness is adjusted in the direction of increasing.

[0134] In other words, if the buffer 64 is not provided, the film thickness can only be adjusted in a decreasing direction, whereas if the buffer 64 is provided, the film thickness can also be adjusted in an increasing direction. This makes it possible to adjust the film thickness to a desired thickness even if there are areas with a small film thickness or areas where the plasma raw material 1 is not applied at all. The buffer 64 corresponds to an embodiment of a holding portion according to the present technology. The edge 65 corresponds to an embodiment of a protrusion according to the present technology.

[0135] Figure 9 is a schematic diagram showing an example of the configuration of the plasma generation mechanism 6. In this example, an outlet is provided in the buffer 64 of Figure 7. In Figure 9, the outlet 68 is schematically shown by a white circle. The buffer 64 is provided opposite the surface 41, and the plasma raw material 1 is discharged from the outlet.

[0136] In this example, three discharge ports 68 are provided in the buffer 64. Each discharge port 68 has a circular shape and is arranged in a row along the left-right direction. Of course, the specific shape, number, and arrangement of the discharge ports 68 are not limited. For example, the discharge ports 68 may be rectangular, or may be arranged in a vertical or diagonal direction, or in a grid pattern.

[0137] As the rotor 20 rotates, plasma raw material 1 accumulates in the buffer 64. The amount of plasma raw material 1 held by the buffer 64 gradually increases, and is eventually discharged from the right side of the skimmer 22a. Furthermore, since an outlet 68 is provided in this example, plasma raw material 1 is also discharged from the outlet 68 at the same time.

[0138] When the rotation speed of the rotor 20 is high, the plasma raw material 1 accumulates in the buffer 64 at a high speed, and discharge from the right side alone may not be enough to keep up, resulting in saturation of the plasma raw material 1 held in the buffer 64. Saturation of the plasma raw material 1 may affect the operation of various mechanisms, including the skimmer 22a. By providing an outlet 68 as in this example, the discharge capacity of the buffer 64 for the plasma raw material 1 is improved, making it possible to prevent saturation. Furthermore, it becomes more difficult for the plasma raw material 1 to be discharged from the left side of the skimmer 22a, minimizing the effect on the film thickness.

[0139] <Fourth embodiment> [Block-shaped skimmer] Fig. 10 is a schematic diagram showing a configuration example of a plasma generation mechanism 6. Fig. 11 is a schematic diagram showing a configuration example of a block member 71. In this example, the plasma generation mechanism 6 has a block member 71. In Fig. 10, the block member 71 is schematically shown with a diagonal line pattern. Fig. 11 shows an example of a specific shape of the block member 71.

[0140] The block member 71 has skimmers 22a and 22b and a cover member 72. The skimmers 22a and 22b have a rectangular plate shape. The cover member 72 has a front surface 73 and a back surface that are fan-shaped with a central angle of approximately 90 degrees, and a side surface 75 that is configured along the front surface 73. Of course, the specific shape of the cover member 72 is not limited, and any shape may be adopted as long as the present technology is feasible. Furthermore, the cover member 72 is made of a rigid material such as metal, but the specific material is not limited.

[0141] Skimmer 22a is arranged parallel to the XY directions so as to cover almost the entire upper surface of side surface 75. Similarly, skimmer 22b is arranged parallel to the YZ directions so as to cover the entire left surface of side surface 75.

[0142] The block member 71 is positioned so that the rear (negative side in the Y direction) sides of the skimmers 22a and 22b face the surface 41 of the disk portion 44 at a predetermined distance. This predetermined distance is set appropriately depending on the desired film thickness. As shown in FIG. 10 , the block member 71 is positioned so that approximately half of its lower side is immersed in the plasma raw material 1 contained in the source container 21. That is, the block member 71 has an immersed portion immersed in the plasma raw material 1 contained in the source container 21 and an exposed portion exposed from the plasma raw material 1 contained in the source container 21. Of the block member 71 (shaded portion) in FIG. 10 , the portion below the liquid surface corresponds to the immersed portion, and the portion above corresponds to the exposed portion. That is, as the height of the liquid surface changes, the shapes of the immersed portion and the exposed portion also change. The cover member 72 is positioned between the rotor 20 and the cover structure 40.

[0143] In this example, the film thickness is finally adjusted by the skimmer 22a, but prior to that, the skimmer 22b adjusts the film thickness. In the portion of the skimmer 22b above the liquid surface (thick line portion 74 in Figure 10), the skimmer 22b scrapes off the plasma raw material 1 adhering to the surface 41 of the disk 44, thereby achieving the usual film thickness adjustment. Meanwhile, the portion of the skimmer 22b below the liquid surface serves to limit the amount of plasma raw material 1 that moves as it is pulled by the disk 44 due to shear stress, to the distance between the skimmer 22b and the disk 44. In other words, when the disk 44 passes through the cover member 72, the plasma raw material 1 located farther from the disk 44 than the distance between the skimmer 22b and the disk 44 does not follow the movement of the disk 44. As a result, the velocity of the plasma raw material 1 at a greater distance is slower than the velocity of the plasma raw material 1 scraped off by the skimmer 22b and adhering to the disk 44. Therefore, the plasma raw material 1 located at a distance hardly moves, and splashing of the liquid is kept to a minimum.

[0144] Splashing is also blocked by the cover member 72. Specifically, of the exposed portion of the cover member 72, the surface 73 blocks splashing toward the front side in FIG. 10 , and the side surface 75 blocks splashing toward the right side, upper left side, etc. In this way, the cover member 72, which functions as a shield, is disposed over a wide area, so that splashing can be further suppressed.

[0145] Depending on the arrangement of other mechanisms in the plasma generation mechanism 6, restrictions may be placed on the arrangement of the skimmers 22a and 22b, making it impossible to adopt the arrangement shown in FIG. 2 . In such cases, by adopting an arrangement such as this example without arranging the skimmer 22a above, it is possible to ensure space for arranging other mechanisms above. The block member 71 corresponds to an embodiment of a first member according to the present technology. The cover member 72 corresponds to an embodiment of a shield according to the present technology.

[0146] Fig. 12 is a schematic diagram showing a configuration example of the plasma generation mechanism 6. In this example, the plasma generation mechanism 6 also has a block member 78. In Fig. 12, the block member 78 is schematically shown with a diagonal line pattern.

[0147] Block member 78 has skimmers 22a and 22b and a cover member 79. Cover member 79 consists of a surface 80, which is a fan-shaped section with a central angle of approximately 150 degrees, with a circular center cut out, and side surfaces. Cover member 79 is positioned opposite surface 41 of disk portion 44, approximately from the 11 o'clock to 4 o'clock position. In other words, the entire block member 78 is exposed to the plasma raw material 1 contained in raw material container 21.

[0148] The portion of the surface 80 near the end in the 11 o'clock direction forms an inclined surface 81 that is inclined toward the depth (negative side in the Y direction). The inclined surface 81 has a generally rectangular shape. In Figure 12, the boundary between the inclined surface 81 and the surface of the surface 80 that is not the inclined surface 81 is indicated by a dashed line. The inclined surface 81 is the surface that faces the cover structure 40 in the depth direction (Y direction). Note that the specific shape, inclination angle, etc. of the inclined surface 81 are not limited.

[0149] In this example, the skimmer 22b also has a rectangular plate shape and is disposed so as to close the end of the side surface at the 4 o'clock direction. As shown in Fig. 12, the skimmer 22b is disposed parallel to the XY plane.

[0150] In this example, the film thickness of the plasma raw material 1 is first adjusted by skimmer 22b, and then the film of plasma raw material 1 reaches the position of inclined surface 81. The plasma raw material 1 then passes between inclined surface 81 and surface 41. In other words, the tip of inclined surface 81 functions as skimmer 22a. The distance between the tip of inclined surface 81 and surface 41 is set appropriately according to the desired film thickness.

[0151] The distance between the surface 41 of the disk portion 44 and the surface 80 of the cover member 79 in the intermediate portion (the position between the skimmers 22a and 22b) may be arbitrary. For example, if the distance in the intermediate portion is increased, a cavity will be formed in the intermediate portion. The plasma raw material 1 may accumulate in the cavity, interfering with the operation of the plasma generation mechanism 6. To prevent this, the distance may be set so that the cavity is as small as possible. This method is promising from the viewpoint of workability. Alternatively, the distance may be continuously changed, or all portions may have the same minimum distance. This degree of freedom in the distance allows for a sloped structure including the sloped surface 81.

[0152] In this example, the cover member 79 can shield a wide area, such as the front, right, and upper sides of FIG. 12 , from liquid splashing. The faster the disk 44 rotates, the more plasma raw material 1 splashes above the liquid surface, and the structure shown in FIG. 2 may not be able to completely prevent liquid splashing. In such cases, arranging the cover member 79 as shown in FIG. 12 can cover the area above the liquid surface and reduce the adverse effects of liquid splashing on the surface irradiated with the energy beam EB. Furthermore, depending on the placement of the skimmers 22a and 22b, they may block the energy beam EB or the radiation R. By providing an inclined surface 81 as in this example and using its tip as the skimmer 22a, it is possible to prevent light from being blocked. That is, the inclined surface 81 is arranged to provide a wide space for the entrance of the energy beam EB or the extraction of the radiation R. This allows light to be stably incident on, for example, a tool or measuring instrument. The block member 78 corresponds to an embodiment of a second member according to the present technology. The cover member 79 corresponds to an embodiment of a shield according to the present technology.

[0153] <Other Embodiments> The present technology is not limited to the above-described embodiments and can realize various other embodiments. [Arrangement on the Back Side] In FIG. 2 , a skimmer 22b may be arranged facing the back side 42 of the disk portion 44. In the portion of the disk portion 44 where the liquid surface is elevated (the right side), splashing occurs not only near the front side 41 and the side surface 39 but also near the back side 42. By additionally arranging a skimmer 22b on the back side 42 side, splashing can be more effectively blocked. Also, in FIGS. 10 and 11 , for example, the skimmer 22a may have a U-shape and be arranged so that the disk portion 44 is sandwiched between the U-shape. In this case, the skimmer 22a faces not only the front side 41 of the disk portion 44 but also the back side 42. This makes it possible to suppress excessive adhesion of plasma raw material 1 to the back side 42 and splashing near the back side 42. Since film thickness adjustment is not required on the back side 42, precise adjustment of the distance between the back side 42 and the skimmer 22a is not necessary.

[0154] [Other Film Thickness Adjusting Mechanisms and Shielding Body] In addition to the configuration shown in Fig. 2 etc., other film thickness adjusting mechanisms may be provided. This allows for more accurate film thickness adjustment. Similarly, other shielding bodies may be provided. This allows for more effective shielding of liquid splashes.

[0155] [Types of Plasma Raw Material] The plasma raw material 1 can be tin, lithium, gadolinium, terbium, gallium, bismuth, indium, or an alloy containing at least one of these materials. For example, if EUV light is extracted as the radiation R and the EUV light is used in a microscope, bismuth is used as the material. Furthermore, if X-rays are generated as the radiation R, indium is used as the material. By using these materials, it is possible to generate high-quality radiation R. The specific type of plasma raw material 1 is not limited. For example, since the plasma raw material 1 also serves as a lubricant between metals, the type of plasma raw material 1 may be determined taking this role into consideration.

[0156] [Types of Energy Beam and Radiation] There are no particular limitations on the specific types of the energy beam EB and the radiation R. For example, laser light can be used as the energy beam EB. This makes it possible to generate high-quality radiation R. Furthermore, for example, extreme ultraviolet light (EUV light) or X-rays can be generated as the radiation R. This makes it possible to use the radiation R efficiently.

[0157] The configurations of the plasma generation mechanism, the rotor, the raw material container, the skimmer, the cover structure, the cover member, the buffer, the edge, the outlet, the block member, and the light source device described with reference to the drawings are merely one embodiment, and can be arbitrarily modified without departing from the spirit of the present technology. In other words, any other configurations for implementing the present technology may be adopted.

[0158] In the present disclosure, when the word "approximately" is used, this is used merely to facilitate understanding of the description, and the use or non-use of the word "approximately" does not have any special meaning. That is, in the present disclosure, concepts that define shape, size, positional relationship, state, etc., such as "center," "central," "uniform," "equal," "same," "orthogonal," "parallel," "symmetrical," "extended," "axial direction," "rectangular," "cubic," "rectangular parallelepiped," "polygonal," "circular," "cylindrical," "disk-shaped," "ring-shaped," "rod-shaped," "plate-shaped," "L-shaped," and "cone-shaped," are concepts that include "substantially center," "substantially central," "substantially uniform," "substantially equal," "substantially the same," "substantially orthogonal," "substantially parallel," "substantially symmetrical," "substantially extended," "substantially axial direction," "substantially rectangular," "substantially cubic," "substantially rectangular parallelepiped," "substantially polygonal," "substantially circular," "substantially cylindrical," "substantially disk-shaped," "substantially ring-shaped," "substantially rod-shaped," "substantially plate-shaped," "substantially L-shaped," and "substantially cone-shaped," etc. For example, states that fall within a predetermined range (e.g., a range of ±10%) based on standards such as "perfectly centered," "perfectly central," "perfectly uniform," "perfectly equal," "perfectly the same," "perfectly orthogonal," "perfectly parallel," "perfectly symmetrical," "perfectly extended," "perfectly axial," "perfectly rectangular," "perfectly cubic," "perfectly rectangular," "perfectly polygonal," "perfectly circular," "perfectly cylindrical," "perfectly disc-shaped," "perfectly ring-shaped," "perfectly rod-shaped," "perfectly plate-shaped," "perfectly L-shaped," and "perfectly cone-shaped" are also included. Therefore, even if the word "approximately" is not added, a concept expressed by adding "approximately" may be included. Conversely, a state expressed by adding "approximately" does not exclude a perfect state.

[0159] In the present disclosure, expressions using "than", such as "greater than A" and "smaller than A", are expressions that comprehensively include both concepts that include the case where it is equivalent to A and concepts that do not include the case where it is equivalent to A. For example, "greater than A" is not limited to cases that do not include equivalent to A, but also includes "A or greater". Furthermore, "smaller than A" is not limited to "less than A" but also includes "A or less". When implementing the present technology, specific settings and the like can be appropriately adopted from the concepts included in "greater than A" and "smaller than A" so that the effects described above can be achieved.

[0160] It is also possible to combine at least two of the features of the present technology described above. That is, the various features described in each embodiment may be arbitrarily combined without distinguishing between the embodiments. Furthermore, the various effects described above are merely examples and are not intended to be limiting, and other effects may also be achieved.

[0161] 6: Plasma generation mechanism 20: Rotating body 21: Raw material container 22a, 22b: Skimmer 36: Lower surface 39: Side surface 40: Cover structure 41: Front surface 42: Back surface 43: Immersion area 46: Adhesion area 60, 72, 79: Cover member 64: Buffer 65: Edge 68: Discharge port 71, 78: Block member 81: Inclined surface 100: Light source device

Claims

1. A light-emitting unit that uses irradiation of an energy beam to convert a liquid raw material into plasma and generate radiation, comprising: a housing section through which the energy beam can pass; a container section arranged inside the housing section and capable of containing the liquid raw material; a rotor that can rotate about a rotation axis that is in a direction intersecting the direction of gravity and has a first region immersed in the liquid raw material contained in the container section, and a second region that is downstream of the first region in the rotation direction of the rotor, to which the liquid raw material adheres and includes the irradiation position of the energy beam; a first film thickness adjustment mechanism that is arranged at a position upstream of the irradiation position and adjusts the film thickness of the liquid raw material adhered to the second region to a first film thickness; and a shield that is arranged between the first film thickness adjustment mechanism and the liquid surface of the liquid raw material contained in the container section, and between the second region and the housing section, and has an opposing surface that faces the liquid surface in the vertical direction.

2. A light-emitting unit that uses irradiation of an energy beam to convert a liquid raw material into plasma and generate radiation, comprising: a container capable of containing the liquid raw material; a rotor that is rotatable about a rotation axis that is in a direction intersecting the direction of gravity and has a first region that is immersed in the liquid raw material contained in the container; and a second region that is downstream of the first region in the rotation direction of the rotor, to which the liquid raw material adheres and that includes the irradiation position of the energy beam; a first film thickness adjustment mechanism that is located upstream of the irradiation position and adjusts the film thickness of the liquid raw material adhered to the second region to a first film thickness; and a second film thickness adjustment mechanism that is located upstream of the first film thickness adjustment mechanism and faces a first surface of the second region that is the surface that includes the irradiation position, and adjusts the film thickness to a second film thickness that is thicker than the first film thickness.

3. A light-emitting unit as described in claim 1, wherein the shielding body is disposed upstream of the first film thickness adjustment mechanism, facing a first surface which is a surface of the second region that includes the irradiation position, and includes a second film thickness adjustment mechanism that adjusts the film thickness to a second film thickness which is thicker than the first film thickness.

4. A light-emitting unit as described in claim 2, further comprising a housing section through which the energy beam can pass, the storage section being disposed inside the housing section, and the second film thickness adjustment mechanism being disposed between the first film thickness adjustment mechanism and the liquid surface of the liquid raw material contained in the storage section, and between the second region and the housing section, and including a shield having an opposing surface facing the liquid surface in the vertical direction.

5. A light-emitting unit according to claim 3 or 4, wherein the second region comprises the first surface, a second surface opposite to the first surface, and a side surface of the rotating body.

6. A light-emitting unit according to claim 5, wherein the shield and the second film thickness adjustment mechanism are arranged so as to divide the rotating body along the liquid surface when viewed from the direction of the rotation axis.

7. A light-emitting unit as described in claim 5, wherein the shield and the second film thickness adjustment mechanism are arranged along the liquid surface at a position upstream of the irradiation position in the rotation direction of the rotating body when viewed from the direction of the rotation axis.

8. A light-emitting unit according to claim 5, wherein the shield is disposed opposite the side surface.

9. The light-emitting unit according to claim 5, wherein the shield is disposed opposite the second surface.

10. A light-emitting unit according to claim 3 or 4, wherein the shielding body and the second film thickness adjustment mechanism are formed by a single member.

11. A light-emitting unit according to claim 10, wherein the shield and the second film thickness adjustment mechanism have a plate-like shape.

12. A light-emitting unit according to claim 3 or 4, wherein the shield and the second film thickness adjustment mechanism are made of different materials, and the second film thickness adjustment mechanism is disposed downstream of the shield.

13. A light-emitting unit as described in claim 5, wherein the first film thickness adjustment mechanism is disposed opposite the first surface, and the first film thickness adjustment mechanism has a protrusion that protrudes toward the first surface and adjusts the film thickness to a first film thickness, and a holding portion that holds the liquid raw material adhered to the first surface.

14. A light-emitting unit according to claim 13, wherein the holding section is provided opposite the first surface and has an outlet for discharging the liquid raw material to the outside of the holding section.

15. A light-emitting unit as described in claim 2, further comprising: a housing portion through which the energy beam can pass and in which a container portion is disposed; and a first member having an immersion portion immersed in the liquid raw material contained in the container portion and an exposure portion exposed from the liquid raw material contained in the container portion, the first film thickness adjustment mechanism, the second film thickness adjustment mechanism, and a shielding body disposed between the rotating body and the housing portion.

16. A light-emitting unit as described in claim 2, further comprising: a housing portion through which the energy beam can pass and in which a container portion is disposed; and a second member exposed from the liquid raw material contained in the container portion, the second member including the first film thickness adjustment mechanism, the second film thickness adjustment mechanism, and a shield disposed between the rotating body and the housing portion.

17. A light-emitting unit according to claim 16, wherein the first film thickness adjustment mechanism has an inclined surface facing the shielding body.

18. A light-emitting unit according to claim 1 or 2, wherein the energy beam is a laser beam.

19. A light-emitting unit according to claim 1 or 2, wherein the radiation is extreme ultraviolet light or X-rays.

20. A light-emitting unit according to claim 1 or 2, wherein the liquid raw material is tin, lithium, gadolinium, terbium, gallium, bismuth, indium, or an alloy containing at least one of these materials.

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