Light source device and film thickness adjustment mechanism

Abstract

The present invention applies a liquid raw material with a constant film thickness even at a high rotational speed.　In a light source device according to the present technology, a contact member is brought into contact with an irradiation surface that is irradiated with an energy beam. The contact member is supported in a manner movable in a direction orthogonal to the irradiation surface and is pressed against the irradiation surface. The cross-sectional area of the contact member on a plane parallel to the irradiation surface increases from the position of contact between the contact member and the irradiation surface toward the contact member side. This makes it possible to apply a liquid raw material with a constant film thickness even at a high rotational speed.

Description

Light source device and film thickness adjustment mechanism

[0001] The present invention relates to a light source device that generates X-rays, extreme ultraviolet light, etc., and a film thickness adjusting mechanism that adjusts the film thickness of a liquid raw material.

[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] JP 2014-216286 A

[0010] For example, in the light source device of Patent Document 1, it is necessary to change the frequency of the energy beam to obtain a sufficient amount of light. However, in this case, the amount of heat generated by irradiation also increases, so a measure to dissipate the heat is required. Therefore, a measure is taken to improve cooling efficiency, for example, by increasing the rotation speed of the rotor so that each area of ​​the rotor is immersed in the plasma raw material for a short period of time.

[0011] However, as the rotation speed of the rotor increases, the film thickness of the source material fluctuates. To address this, for example, grooves can be provided on the surface of the rotor, but this may not be enough to suppress the film thickness fluctuation of the source material.

[0012] In view of the above circumstances, an object of the present invention is to provide a light source device and a film thickness adjustment mechanism that are capable of applying a liquid material at a constant film thickness even at a high rotation speed.

[0013] In order to achieve the above object, a light source device according to one aspect of the present technology converts a liquid raw material into plasma by irradiating it with an energy beam to extract radiation, and includes a beam source, a first rotating body, and a film thickness adjustment mechanism. The beam source irradiates the energy beam. The first rotating body has an irradiation surface to which the liquid raw material adheres and which is irradiated with the energy beam. The film thickness adjustment mechanism includes an abutting member and a support member. The abutting member abuts against the irradiation surface. The support member supports the abutting member so that the abutting member can move in a direction perpendicular to the irradiation surface. The abutting member is pressed against the irradiation surface, and a cross-sectional area in a plane parallel to the irradiation surface increases from the contact position of the abutting member and the irradiation surface toward the abutting member.

[0014] In this light source device, a contact member is in contact with the irradiation surface that is irradiated with the energy beam. The contact member is supported so as to be movable in a direction perpendicular to the irradiation surface and is pressed against the irradiation surface. The cross-sectional area of ​​the contact member in a plane parallel to the irradiation surface increases from the contact position between the contact member and the irradiation surface toward the contact member. This makes it possible to apply the liquid source with a constant film thickness even at high rotation speeds.

[0015] The contact member may be a second rotating body having a central axis that is an axis in a direction in which the contact member is movable.

[0016] The abutment member may have a spherical shape.

[0017] The contact member may have a bullet-like shape, and a tip thereof may contact the irradiation surface.

[0018] The contact member may have a cylindrical shape, and a side surface of the contact member may contact the irradiation surface.

[0019] The support member may have an elastic body that presses the contact member against the irradiation surface.

[0020] The support member may support the contact member so as to be movable in the direction of gravity. In this case, the contact member may be pressed against the irradiation surface by its own weight.

[0021] The first rotating body may have a disk shape including a circular first surface, a circular second surface opposite to the first surface, and a side surface.

[0022] The irradiation surface may be the first surface.

[0023] The irradiation surface may be the side surface.

[0024] The irradiation surface may have a groove formed therein. In this case, the energy beam may be irradiated onto the groove. The abutting member may abut against the groove.

[0025] The groove may have the same shape as the contact member.

[0026] The cross section of the groove may have a shape different from the cross section of the contact member.

[0027] The groove may have a cross section that is at least one of a triangular shape, a rectangular shape, a semicircular shape, and a trapezoidal shape.

[0028] The contact member may have a cross-sectional area in a plane perpendicular to a rotation direction of the first rotor that increases toward a downstream side in the direction of rotation.

[0029] The contact member may have a flat tapered surface on the upstream side of the first rotor in the direction of rotation.

[0030] The contact member may have a curved tapered surface on the upstream side of the rotation of the first rotor.

[0031] The contact member may rotate in conjunction with the rotation of the first rotating body.

[0032] The support member may have a cylindrical shape.

[0033] The light source device may further include a container capable of containing the liquid raw material. In this case, the rotating body may be immersed in the liquid raw material contained in the container.

[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] A film thickness adjustment mechanism according to one aspect of the present technology includes a first rotating body, a contact member, and a support member. The first rotating body has an attachment surface to which a liquid precursor is attached. The contact member contacts the attachment surface. The support member supports the contact member so that the contact member can move in a direction perpendicular to the attachment surface. The contact member is pressed against the attachment surface, and a cross-sectional area of ​​the contact member in a plane parallel to the attachment surface increases from a contact position between the contact member and the attachment surface toward the contact member.

[0038] According to the present invention, it is possible to apply a liquid source to a constant film thickness even at a high rotation speed. Note that the effects described here are not necessarily limited to those described herein, and any of the effects described in this disclosure may be applied.

[0039] 10A is a schematic diagram showing a configuration example of a light source device according to a first embodiment of the present invention. FIG. 2B is a schematic diagram showing a configuration example of a rotor and skimmer. FIG. 2C is a cross-sectional view taken along line B-B in FIG. 2B. FIG. 13A is an enlarged view of the vicinity of a sphere. FIG. 13B is an enlarged view of the vicinity of a sphere. FIG. 2D is a cross-sectional view of a bullet-shaped abutment member. FIG. 14 is a schematic diagram showing a configuration example of a groove. FIG. 15 is a schematic diagram showing variations of the groove. FIG. 16 is a cross-sectional view showing a configuration example of a rotor and skimmer. FIG. 17 is a cross-sectional view taken along line D-D in FIG. 9. FIG. 10A is an enlarged view of FIG. 10A. FIG. 18 is a schematic diagram showing a configuration example of an LDP light source device. FIG. 19 is an enlarged view of a skimmer. FIG. 2D is a cross-sectional view taken along line E-E in FIG. 2B. FIG. 19 is an enlarged view of the vicinity of the abutment member in FIG. 2A. FIG. 20 is an enlarged view of the vicinity of the abutment member in FIG. 2B. FIG. 21 is a schematic diagram showing variations of the abutment member.

[0040] Hereinafter, embodiments of the present technology will be described with reference to the drawings.

[0041] <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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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 .

[0052] 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.

[0053] 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).

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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 using 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.

[0065] 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 containing liquid plasma raw material 1. The rotor 20 and raw material container 21 are disposed inside the vacuum chamber 3.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] [Skimmer] Fig. 2 is a schematic diagram showing an example configuration of the rotor 20 and the skimmer 40. Fig. 2A shows the rotor 20 as viewed slightly obliquely from the rear of the paper in Fig. 1 (negative side in the Z direction). Fig. 2B shows the rotor 20 as viewed from the direction of arrow A in Fig. 1 (positive side in the Y direction). Fig. 3 is a cross-sectional view taken along line B-B in Fig. 2B. Fig. 3 shows the cross-section of the rotor 20 as viewed from the direction of arrow B in Fig. 2B (rear of the paper in Fig. 1, negative side in the Z direction).

[0073] The rotating body 20 has a disk portion 44 and a shaft portion 45. The disk portion 44 has a disk shape and is composed of a circular front surface 41, a circular back surface 42 which is the surface opposite to the front surface 41, and a side surface 43. The rotating body 20 is disposed so that the front surface 41 and the back surface 42 are generally parallel to the XZ plane. The front surface 41 is located on the positive side of the Y direction, and the back surface 42 is located on the negative side of the Y direction.

[0074] The shaft portion 45 has an elongated cylindrical shape and is disposed so that its circular surface (upper or lower surface) abuts against the center of the back surface 42 of the rotating body 20. In Figures 2A and 3, the rotation axis H of the rotating body 20 is indicated by a dashed line. In Figure 2B, the rotation axis H is indicated by a black circle. The rotation axis H is parallel to the Y axis, and the shaft portion 45 extends along the rotation axis H. When the shaft portion 45 rotates around the rotation axis H, the rotating body 20 (disk portion 44 and shaft portion 45) rotates integrally.

[0075] 2A and 2B, the direction of rotation of the rotating body 20 is indicated by an arrow. As such, the rotating body rotates counterclockwise when viewed from the positive side of the Y direction. This direction corresponds to the direction of rotation in which the right side of the rotating body 20 faces the back and the left side faces the front in FIG. 3.

[0076] The rotor 20 is made of a rigid material such as metal. Alternatively, a material with low reactivity with the plasma raw material 1, the energy beam EB, and the radiation R may be used as appropriate to prevent deterioration due to reaction with these. The specific configuration of the rotor 20 is not limited thereto. For example, within the scope of feasibility of the present technology, the rotor 20 may be configured to have a polygonal shape or to rotate clockwise.

[0077] The rotating body 20 corresponds to an embodiment of a first rotating body according to the present technology. 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.

[0078] 3 shows a schematic diagram of the plasma raw material 1 attached to the disk portion 44 using a hatched pattern. In this embodiment, the plasma raw material 1 is attached to the entire disk portion 44 with a predetermined film thickness. Note that while FIG. 3 shows the film thickness as being roughly the same at any position, in reality the film thickness varies depending on the position where the plasma raw material 1 is attached.

[0079] The portion of surface 41 that is not immersed in raw material container 21 corresponds to an embodiment of the attachment surface, that is, the surface to which plasma raw material 1 adheres. Also, the surface to which plasma raw material 1 adheres corresponds to an embodiment of the irradiation surface, that is, the surface to which energy beam EB is irradiated.

[0080] Furthermore, in this embodiment, a skimmer 40 is provided for the rotor 20. The skimmer 40 is indicated by a dashed rectangle in Fig. 3. The skimmer 40 has a sphere 46, a cylindrical body 47, an elastic body 48, and a sphere holder 49.

[0081] The sphere 46 has a spherical shape and is made of a material such as metal. The material, diameter, etc. of the sphere 46 are not limited. The cylinder 47 has a cylindrical shape and is configured so that the diameter of the cylinder is equal to or greater than the diameter of the sphere 46. In this embodiment, the diameter of the cylinder 47 and the diameter of the sphere 46 are approximately the same size, and the sphere 46 is stored inside the cylinder 47 with approximately no gaps. Other specific configurations of the cylinder 47, such as the material, diameter, length, etc., are not limited. For example, as long as the present technology is feasible, a configuration in which the cylinder 47 has a polygonal cylindrical shape can also be adopted.

[0082] The elastic body 48 is a member having elasticity. In this embodiment, a spring is used as the elastic body 48. As shown in FIG. 2B , in this embodiment, two springs are arranged side by side along the Z direction, but the number and arrangement of the elastic bodies 48 are not limited. Furthermore, the specific configuration of the elastic body 48, such as the type and elastic force, is not limited. The sphere retainer 49 is a member having a plate-like shape.

[0083] 3, in this example, a cylindrical body 47 is disposed so as to extend along the Y direction, and accommodates therein, from the top, an elastic body 48, a sphere holder 49, and a sphere 46. Although not shown in the figure, for example, the top surface of the cylindrical body 47 is closed, and the top end of the elastic body 48 is fixed to this top surface.

[0084] The elastic body 48 presses the sphere 46 against the surface 41. Specifically, the sphere 46 receives the elastic force (downward force) of the elastic body 48 via the sphere retainer 49, and is pressed against the surface 41. As a result, when the rotating body 20 is not rotating, the lower end of the sphere 46 is in contact with the surface 41.

[0085] The sphere 46 corresponds to an embodiment of a contact member according to the present technology. The cylindrical body 47, the elastic body 48, and the sphere holder 49 correspond to an embodiment of a support member according to the present technology. The rotating body 20 and the skimmer 40 correspond to an embodiment of a film thickness adjusting mechanism according to the present technology.

[0086] [Adjusting Film Thickness] Sphere 46 is supported by cylindrical body 47, elastic body 48, and sphere retainer 49 so that it can move in the Y direction. Specifically, when rotor 20 rotates, the liquid pressure of the plasma raw material 1 adhering to surface 41 acts on the lower part of sphere 46. As a result, sphere 46 is subjected to an upward force as shown in FIG. 3. Meanwhile, sphere 46 is subjected to a downward force from elastic body 48, and when the upward force of the plasma raw material 1 exceeds the downward force of elastic body 48, sphere 46 moves upward. The downward force of elastic body 48 gradually increases as sphere 46 moves upward, and sphere 46 eventually comes to rest at a position where the force of the plasma raw material 1 and the force of elastic body 48 are balanced.

[0087] That is, during rotation, sphere 46 does not come into contact with surface 41 but floats slightly, allowing plasma raw material 1 to flow in. Conversely, when rotation stops, the upward force of plasma raw material 1 no longer acts on sphere 46, so sphere 46 comes into contact with surface 41 and remains stationary. In this way, sphere 46 moves up and down as rotor 20 rotates. However, because sphere 46 is fixed by cylindrical body 47, it does not move left and right or in the depth direction.

[0088] The direction (Y direction) in which the sphere 46 is movably supported corresponds to one embodiment of a direction perpendicular to the irradiation surface (surface 41, i.e., a plane parallel to the XZ plane). Note that a case in which the cylindrical body 47 is disposed at an angle with respect to the Y direction and the sphere 46 moves at an angle is also included in the case in which the sphere 46 is supported movably in the Y direction. In other words, a case in which the sphere 46 is movable in a direction including a Y direction component is included in the scope of the present technology. A bearing mechanism may be provided between the sphere 46 and the cylindrical body 47 to allow the sphere 46 to move smoothly.

[0089] When the force that the sphere 46 receives from the elastic body 48 is large, the gap between the sphere 46 and the surface 41 becomes small. For example, this state can occur when the spring constant of the spring that is the elastic body 48 is large. Conversely, when the force that the sphere 46 receives from the elastic body 48 is small, the gap becomes small.

[0090] Furthermore, the gap will be smaller if the force acting on the sphere 46 from the plasma raw material 1 is small. For example, if the rotation of the rotor 20 is slow, the liquid pressure will decrease, and this condition can occur. Conversely, if the rotation of the rotor 20 is fast, the gap will be larger.

[0091] The size of the gap also depends on the shape and material of each component of the rotor 20 and skimmer 40, as well as the material of the plasma raw material 1. That is, by appropriately determining these components, it is possible to control the size of the gap to a desired value. In other words, it is possible to adjust the film thickness of the plasma raw material 1 at the position of the skimmer 40 to a desired value.

[0092] In this embodiment, light source device 100 is configured so that the distance between the center of rotation and the tip of sphere 46 and the distance between the center of rotation and irradiation position I are approximately equal. Therefore, the portion of surface 41 that was located at the position of skimmer 40 moves to irradiation position I due to the rotation of rotor 20. In other words, plasma raw material 1 adjusted to the desired film thickness at that portion moves to irradiation position I.

[0093] As a result, the energy beam EB is irradiated onto the plasma raw material 1, which has adhered to the desired thickness, at irradiation position I. It is possible that the thickness may increase during rotation due to centrifugal force, etc., but in that case, by taking into account the amount of increase in thickness and adjusting the thickness at the skimmer 40 position to be smaller in advance, it is possible to obtain the desired thickness at irradiation position I. The amount of increase in thickness is determined by factors such as the rotation speed of the rotor 20, and can be determined by calculation or trial taking these values ​​into account.

[0094] 4 is an enlarged view of the vicinity of the sphere 46. In this embodiment, the cross-sectional area of ​​the abutting member abutting against the surface 41 in a plane parallel to the surface 41 increases from the contact position between the abutting member and the surface 41 toward the abutting member.

[0095] 4A, a plane 52 is shown by a dashed line. The plane 52 is a plane parallel to the XZ plane and corresponds to a plane parallel to the surface 41. The distance between the plane 52 and the surface 41 is d １In FIG. 4A, a cross section of the sphere 46 cut by a plane 52 is shown with a diagonal line pattern. The cross section area of ​​the cross section is S １ It is as follows.

[0096] Similarly, in FIG. 4B, the distance between plane 52 and surface 41 is d １ Greater than d ２ Here, the cross-sectional area S ２ is the cross-sectional area S in FIG. １ That is, if the distance between the surface 41 and the plane 52 increases, the cross-sectional area of ​​the sphere 46 when cut by the plane 52 also increases.

[0097] Therefore, the sphere 46 has a property that the cross-sectional area increases as the plane 52 moves from the contact position toward the contact member (toward the sphere 46, the positive side in the Y direction). For simplicity, this property may be referred to as the property of increasing cross-sectional area hereinafter. In this example, the sphere 46 is used as the contact member, but any shape of contact member having the property of increasing cross-sectional area may be used.

[0098] 5 is a cross-sectional view of a bullet-shaped abutment member. In this example, the abutment member has a bullet-shaped shape, and the tip abuts against the surface 41. The bullet body 55 shown in FIG. 5 also has the property of increasing the cross-sectional area, so an abutment member having such a shape may also be used.

[0099] Alternatively, a conical or pyramidal shape with only a spherical tip, or a shape with a flat tip but with an increasing cross-sectional area, may be employed; the specific shape of the contact member is not limited. In the example using the sphere 46, the cross-sectional area of ​​the upper half of the sphere 46 decreases toward the positive Y-axis direction. This type of contact member with an increasing cross-sectional area only near the contact position is also within the scope of the present technology. Similarly, the cross-sectional area of ​​the projectile body 55 does not change midway through the projectile body, and such a contact member is also within the scope of the present technology.

[0100] The abutment member may be a rotating body having a central axis that is an axis in the direction in which the abutment member can move. In the examples of FIGS. 2 to 5, the direction in which the abutment member can move is the Y direction. Since the sphere 46 and the cannonball body 55 are both rotating bodies having a central axis that is the Y axis, they are rotating bodies having a central axis that is an axis in the direction in which the abutment member can move. The rotating body is not limited to these, and for example, a cone or a truncated cone can also be the above rotating body. The sphere 46 and the cannonball body 55 correspond to an embodiment of a second rotating body according to the present technology.

[0101] As described above, in the light source device 100 according to this embodiment, an abutting member abuts against the surface 41 of the rotating body 20 that is irradiated with the energy beam EB. The abutting member is supported so as to be movable in a direction perpendicular to the surface 41, and is pressed against the surface 41. The cross-sectional area of ​​the abutting member in a plane parallel to the surface 41 increases from the contact position between the abutting member and the surface 41 toward the abutting member. This makes it possible to apply the liquid source with a constant film thickness even at high rotation speeds.

[0102] In an EUV light source device, the frequency of the energy beam EB must be increased to obtain high output. However, in this case, the amount of heat generated by irradiation also increases, so some measure to dissipate the heat is necessary. For example, by increasing the rotation speed of the rotor 20, each area of ​​the rotor 20 is immersed in the plasma raw material 1 for a short time, thereby increasing the cooling efficiency.

[0103] The speed of such a rotor is preferably 10 m / sec or higher. However, when rotor 20 rotates at such a high speed, the plasma raw material 1 collides with the contact member at high speed. Furthermore, the amount of plasma raw material 1 lifted from raw material container 21 by rotor 20 also increases, so more plasma raw material 1 collides with the contact member. These two factors increase the liquid pressure that plasma raw material 1 exerts on the skimmer.

[0104] If the liquid pressure increases, the skimmer moves significantly, making it difficult to control the film thickness. In the worst case, stacking may occur, causing the light source device 100 to stop functioning.

[0105] In this embodiment, a member with an increasing cross-sectional area is used as the contact member. This allows the plasma raw material 1 to be gradually pushed aside by the contact member, so the liquid pressure that the contact member receives from the plasma raw material 1 becomes relatively small. This makes it possible to eliminate problems such as skimmer 40 movement or stacking.

[0106] For example, if a flat plate-shaped member (a member that does not have the property of increasing cross-sectional area) is used as the contact member, the surface of the contact member facing the direction in which the plasma raw material 1 approaches (the surface on the near side in Figure 3) is flat, so the plasma raw material 1 will collide with the entire surface. In other words, the liquid pressure that the contact member receives will be large.

[0107] On the other hand, in this embodiment, the plasma raw material 1 is pushed away while avoiding areas other than the tip of the sphere 46, so the liquid pressure received by the contacting member is smaller than when a flat-shaped member is used, making it possible to prevent problems caused by liquid pressure.

[0108] Furthermore, by using a sphere 46 or a projectile 55 as the contact member, the portion that comes into contact with the plasma raw material 1 is a point, making it possible to precisely adjust the film thickness at one location. This effect can also be achieved with various other contact members whose tips make contact at a point, and any suitable shape can be adopted. This configuration is particularly effective in an LPP-type light source device, in which the irradiation area of ​​the energy beam EB is relatively small. As an example, in the LPP system, the irradiation surface is a circle with a diameter of approximately tens to hundreds of μm, and the portion where the film thickness is adjusted is a circle with a diameter of 1 mm or less. Of course, the shapes of the irradiation surface and the portion where the film thickness is adjusted are not limited to these.

[0109] By using a contact member with a spherical tip, it is possible to reduce the frictional force acting on the tip and suppress wear of the contact member. Of course, the use of a contact member with a sharp tip is not excluded from the scope of this technology.

[0110] In this embodiment, the contact member is supported by a cylindrical body 47, and a rotating body having a central axis that is the axis in which the contact member can move is used as the contact member. In other words, the contact member is supported so that it cannot move in any direction other than the direction of the rotation axis. This suppresses wobble of the sphere 46 due to the influence of the hydraulic pressure.

[0111] In this embodiment, the contact member is pressed by the elastic body 48. This allows the contact member to operate stably. Furthermore, since a constant force acts on the contact member, it becomes possible to adjust the film thickness with even higher precision.

[0112] In this embodiment, a disk-shaped member is used as the rotor 20, and the energy beam EB is irradiated onto the circular surface 41. A raw material container 21 is also arranged, and the rotor 20 is immersed in the plasma raw material 1 contained in the raw material container 21. This makes it possible to realize a high-quality LPP type light source device 100.

[0113] Second Embodiment A more detailed embodiment of the light source device 100 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 light source device 100 described in the above embodiment will be omitted or simplified.

[0114] [Groove portion] Fig. 6 is a schematic diagram showing an example of the configuration of the groove portion. Fig. 6A shows the vicinity of the skimmer 40 of the disk portion 44 as viewed obliquely from the front right side in Fig. 2A. Fig. 6B is a cross-sectional view as seen from the positive side in the Z direction, similar to Fig. 3.

[0115] In this example, grooves 58 are formed on the front surface 41 and the back surface 42 of the disk portion 44, the energy beam EB is irradiated onto the grooves 58, and the abutment member abuts against the grooves 58. The grooves 58 have a predetermined width, and when viewed from a direction perpendicular to the disk portion 44 (the Y direction), they have a ring shape centered on the rotation axis H of the rotating body 20. The grooves 58 are formed at positions that overlap both the abutment position of the sphere 46 and the irradiation position I of the energy beam EB.

[0116] Therefore, the thickness of the film of plasma raw material 1 adhering to the inside of groove 58 is adjusted by sphere 46, and as rotor 20 rotates, energy beam EB is irradiated onto plasma raw material 1 in groove 58.

[0117] Similar to the example shown in FIG. 3 and other figures, the sphere 46 is supported by a cylindrical body 47, an elastic body 48, and a sphere holder 49. Note that the elastic body 48 and the sphere holder 49 are not shown in FIG. 6 . Furthermore, in this example, the cylindrical body 47 is fixed by a fixing member 59. The fixing member 59 has a rectangular frame shape with three sides and is arranged so that the disk portion 44 is sandwiched between the three sides. Openings are formed at the top and bottom of the fixing member 59, and the cylindrical body 47 is fixed by fitting it into each of the two openings. Use of the fixing member 59 makes it possible to stably hold the cylindrical body 47 and the sphere 46. The specific shape and material of the fixing member 59 are not limited. Furthermore, the method of fixing the cylindrical body 47 is not limited to the method using the fixing member 59.

[0118] As shown in FIG. 6B , in this example, the cross section of the groove 58 is rectangular. The sphere 46 has a diameter that allows it to abut against the bottom of the groove 58. Furthermore, when the sphere 46 abuts against the bottom of the groove 58, the sphere 46 also abuts against the boundaries of the groove (the upper left and upper right corners of the upper groove 58 and the lower left and lower right corners of the lower groove 58 in FIG. 6B ). This allows the film thickness at the abutment position between the tip of the sphere 46 and the bottom of the groove 58 to be adjusted to a desired value. The energy beam EB is then irradiated to that position. To achieve this configuration, the shapes of the groove 58 and the sphere 46, the irradiation angle of the energy beam EB, and other configurations are appropriately selected.

[0119] If the diameter of the sphere 46 is small, it is possible that the sphere 46 may come into contact with the bottom of the groove 58 but not with the boundary. Even in such a case, the film thickness at the bottom of the groove 58 is still adjusted, and no problem occurs.

[0120] The grooves 58 formed on the surface 41 of the disk portion 44 allow the sphere 46 to sit more securely and improve positional stability, thereby preventing the sphere 46 from moving in an unexpected direction.

[0121] [Variations of Groove Sections] FIG. 7 is a schematic diagram showing variations of groove sections. Groove section 62 has a triangular cross section when cut in the XY plane. Groove section 63 has a rectangular cross section, similar to groove section 58 shown in FIG. 6B . The cross section of groove section 63 may be either a square or rectangular cross section. Groove section 64 has a semicircular cross section. The cross section may also have a shape equivalent to a portion of a semicircle (e.g., a shape surrounded by a 120-degree arc and a chord). Groove section 65 has a trapezoidal cross section. In this example, the width of the upper base is smaller than the width of the lower base, but the width of the upper base may also be larger than the width of the lower base. In FIG. 7 , the width W and depth D of groove section 62 are indicated by arrows. The values ​​of the width W and depth D of each of groove sections 62 to 65 may be selected appropriately according to the size of sphere 46, etc.

[0122] Of these, the groove 64 has the same shape as the sphere 46. That is, the groove 64 has a hemispherical shape, and the lower side of the sphere 46 also has a hemispherical shape. This makes it possible to further improve the positional stability of the sphere 46. Note that the groove 64 may have a large hemispherical shape and the sphere 46 a small hemispherical shape, for example, and the spheres may have different sizes but the same shape.

[0123] Furthermore, the cross sections of grooves 62, 63, and 65 have a different shape from the cross section of sphere 46. That is, the cross section of each groove has a different shape from the cross section (semicircular) of sphere 46. This allows the raw material not pushed aside by sphere 46 to act as a buffer, making this a more effective configuration for maintaining a constant film thickness. For example, when the rotation speed of rotor 20 is high, the film thickness of plasma raw material 1 may become thin, resulting in an insufficient amount. In such cases, by using a configuration in which the shape of sphere 46 and the shape of the grooves are different, more of the plasma raw material 1 is not pushed aside by sphere 46, and this amount acts as a buffer, making it possible to compensate for the shortage of plasma raw material 1.

[0124] The specific shape of the groove 58 is not limited. For example, if the shape of the groove 62 is used, the contact position between the sphere 46 and the groove 62 will be on the diagonal side of a triangle, and the energy beam EB will be irradiated at an angle relative to that position. This is not limiting, and the energy beam EB may be irradiated onto the plasma raw material 1 accumulated at the bottom in the center of the triangle. In this case, the shapes of the sphere 46 and the groove 62 are adjusted so that the plasma raw material 1 accumulates at the bottom with the desired film thickness. Such cases where the contact position and the irradiation position are slightly different in strict terms are also within the scope of the present technology.

[0125] <Third embodiment> [Pressure due to own weight] Fig. 8 is a cross-sectional view showing an example of the configuration of the rotor 20 and skimmer 40. In this example, the rotor 20 and skimmer 40 are arranged obliquely with respect to the direction of gravity (Z direction). Specifically, the rotor 20 and the like are arranged so that the rotation axis H forms an angle of approximately 45 degrees with respect to the Y axis with respect to the Z axis. Of course, the arrangement angle is not limited to this value.

[0126] The projectile 55 is supported by the cylindrical body 47 so as to be movable in the direction of gravity. In this example, the projectile 55 is movable in the direction of arrow C (a 45-degree diagonal direction), but since this direction includes a component in the direction of gravity, it can be said to be movable in the direction of gravity. Furthermore, since gravity acts on the projectile 55 in the negative direction of the Z axis, the tip of the projectile 55 is pressed against the surface 41 of the disk portion 44 by the force of the 45-degree diagonal component (the force in the downward and right direction of arrow C). In other words, the projectile 55 is pressed against the surface 41 by its own weight.

[0127] In this case, for example, by selecting a material with a high density as the material for the projectile 55, the weight acting on the projectile 55 increases, making it possible to reduce the film thickness after adjustment. Conversely, by selecting a material with a low density, it is possible to increase the film thickness. Furthermore, by changing the angle of the rotor 20, the magnitude of the oblique component of the weight acting on the projectile 55 changes, and the film thickness also changes. By appropriately selecting various other configurations, such as the size of the projectile 55, it is possible to obtain the desired film thickness. This eliminates the need for mechanisms such as the elastic body 48 and the spherical retainer 49 for pressing the abutting member against the surface 41, making it possible to realize the light source device 100 with a simple configuration.

[0128] <Fourth embodiment> [Application to LDP] Fig. 9 is a schematic diagram showing an example of the configuration of an LDP light source device. Fig. 10A is a cross-sectional view taken along line DD in Fig. 9. Fig. 10B is an enlarged view of Fig. 10A.

[0129] In this example, an LDP-type light source device is used as the light source device. Fig. 9 shows a plasma generation mechanism 67 in an LDP-type light source device. The plasma generation mechanism 67 has two rotors 68 and 69. The rotor 68 has a disk portion 70 and a shaft portion 71. The rotor 69 has a disk portion 72 and a shaft portion 73. The configuration of the rotors 68 and 69 is similar to the configuration of the rotor 20 in the LPP-type light source device 100 shown in Fig. 2 etc., but is of course not limited to this configuration.

[0130] Rotating body 68 is disposed on the right side of FIG. 9, and rotating body 69 is disposed on the left side. Rotating body 68 is immersed in raw material container 79, and rotating body 69 is immersed in raw material container 80. FIG. 10A shows a cross section taken along line D-D in FIG. 9 as viewed from above (positive side in the Z direction). As shown in FIG. 10A, rotating body 68 is disposed with its rotation axis slightly tilted counterclockwise. Similarly, rotating body 69 is disposed with its rotation axis slightly tilted clockwise.

[0131] A skimmer 74 is disposed on the right side of the disk portion 70. A skimmer 66 is disposed on the left side of the disk portion 72. The configuration of the right-side skimmer 74 will be described below. The configuration of the skimmer 66 is similar to that of the skimmer 74. Figure 10B is an enlarged view of the skimmer 74 (the rectangular portion enclosed by the dashed line in Figure 10A).

[0132] Similar to the skimmer 40 shown in FIG. 2 and elsewhere, the skimmer 74 includes a sphere 75, a cylindrical body 76, a fixing member 77, an elastic body, and a sphere holder. The elastic body and sphere holder are not shown in FIG. 10B . The fixing member 77 has a rectangular frame shape with three sides and is arranged so that the disk portion 70 is sandwiched between the three sides. In this example, an opening is formed in the fixing member 77 at a position facing the side surface 78 of the disk portion 70, and the cylindrical body 76 is fixed by fitting into the opening. Furthermore, a sphere 75 is inserted into the cylindrical body 76, and the tip of the sphere 75 abuts against the side surface 78 of the disk portion 70.

[0133] As a result, the film thickness of the plasma raw material 1 adhering to the side surface 78 is adjusted to the desired value by the sphere 75. In an LDP-type light source device, the energy beam EB is irradiated onto the side surface of the rotating body, not onto the surface. The configuration of the present technology is also applicable in such cases, making it possible to precisely adjust the film thickness. In this example, the portion of the side surface 78 that is not immersed in the raw material container 21 is the surface to which the plasma raw material 1 adheres, and corresponds to one embodiment of the irradiation surface irradiated with the energy beam EB, according to the present technology. Note that a groove may be formed in the side surface 78.

[0134] Fifth Embodiment [Film Thickness Adjustment Using a Roller] Fig. 11 is a schematic diagram showing an example of the configuration of an LDP light source device, and Fig. 12 is an enlarged view of a skimmer.

[0135] Figure 11 shows the rotor 68 and the raw material container 79. In this example, the light source device is also an LDP type, and a skimmer 81 is disposed on the side surface 78 of the disk portion 70. Figure 12A is an enlarged view of the skimmer 81 (the rectangular portion enclosed by the dashed line in Figure 11). Figure 12B is an enlarged view in which the fixing member 84 in Figure 12A is made transparent.

[0136] The skimmer 81 has a roller 82, an elastic body 83, and a fixed member 84. The roller 82 has a cylindrical shape and has circular top, bottom, and side surfaces 85. It also has protrusions 86 at the center of the top and bottom surfaces. The elastic body 83 in this example is two springs.

[0137] The fixed member 84 has a rectangular frame shape consisting of three sides, and is arranged so that the three sides sandwich the disk portion 70. Openings 87 are formed in two side portions (surfaces parallel to the XZ plane) of the fixed member 84, and an elastic body 83 is arranged inside the opening 87 so that it faces sideways (with its axis extending in the X direction). Furthermore, the protruding portion 86 of the roller 82 is fitted into the left end of the opening 87, and the protruding portion 86 is pressed to the left by the elastic body 83.

[0138] That is, the entire roller 82 receives a leftward force from the elastic body 83 and is pressed against the side surface 78 of the disk portion 70. As a result, the side surface 85 of the roller 82 is positioned so as to abut against the side surface 78 of the disk portion 70.

[0139] This configuration also makes it possible to adjust the film thickness. By using the roller 82, it becomes possible to adjust the film thickness over a wide area with high precision. Since the light-emitting area of ​​an LDP-type light source device is wide (the energy beam EB is irradiated over a wide range), the configuration using the roller 82 is particularly effective for an LDP-type light source device.

[0140] The specific configuration of the roller 82, such as its size, is not limited. As an example, the thickness (length in the Y direction) of the roller 82 is set to be slightly larger than the thickness of the disk portion 70. Furthermore, if grooves are formed on the side surface 78 of the disk portion 70, rollers 82 smaller than the larger grooves may be brought into contact with the larger grooves, and the film thickness at the contact position between the inside of the grooves and the rollers 82 may be adjusted. Alternatively, rollers 82 larger than the smaller grooves may be brought into contact with the smaller grooves, and the energy beam EB may be irradiated onto the plasma raw material 1 accumulated inside the grooves, similar to the triangular grooves 62 in FIG. 7 . Alternatively, a configuration may be adopted in which the rollers 82 are placed against the surface of the disk portion 70. The rollers 82 correspond to one embodiment of a contact member according to the present technology.

[0141] <Sixth embodiment> [Variations of contact member] Fig. 13A is a cross-sectional view taken along line E-E in Fig. 2B. Figs. 13B and 13C are enlarged views of the vicinity of the contact member in Fig. 13A. In this example, the cross section of the contact member 90 has a rectangular shape with rounded corners on the bottom left and bottom right.

[0142] The cross-sectional area of ​​the abutment member 90 in a plane perpendicular to the rotation direction of the rotating body 20 increases toward the downstream side of the rotation. The rotation direction of the rotating body 20 is the left-right direction in Figure 13, and the plane perpendicular to the rotation direction corresponds to the plane perpendicular to the Z axis, i.e., the XY plane. In Figures 13B and 13C, the XY plane 91 is shown by solid and dashed lines.

[0143] 13B shows a cross section of the contact member 90 cut in the vicinity of the left end thereof on the XY plane 91 by a broken line. Also, FIG. 13C shows a cross section of the contact member 90 cut in the XY plane 91 slightly to the right of the cross section of FIG. 13B by a broken line. Here, the cross section of the contact member 90 has a rounded bottom left corner, so the cross section area S ４ is the cross-sectional area S of FIG. ３ Since the direction of rotation of the rotor 20 is from left to right, the downstream side of the rotation is the right side. Therefore, it can be said that the cross-sectional area of ​​the contact member 90 increases toward the downstream side of the rotation.

[0144] In this example, the cross-sectional area does not change in the center of the abutment member 90, and decreases at the right end as it moves downstream in the direction of rotation. However, cases in which the cross-sectional area increases only at the left end of the abutment member 90 are also included in the scope of this technology.

[0145] As a result, the plasma raw material 1 approaching the contact member 90 is gradually pushed aside by the left end of the contact member 90 as it progresses, so the liquid pressure that the contact member 90 receives is relatively smaller than when a flat contact member is used, making it possible to prevent problems caused by liquid pressure.

[0146] Furthermore, in this example, the abutment member 90 has a curved tapered surface on the upstream side of the rotation of the rotating body 20. The rounded portion at the bottom left corner shown in Figures 13B and 13C is the tapered surface 92. Here, the upstream side of the rotation is the left side, so it can be said that the abutment member 90 has the tapered surface 92 on the upstream side of the rotation.

[0147] This further reduces the liquid pressure that the contact member 90 receives. As an example, the film thickness before the plasma raw material 1 flows in (to the left of the contact member 90) is several hundred microns, and after the flow in (to the right, after film thickness adjustment) is several tens of microns. In this case, it is desirable that the upper end of the tapered surface 92 be positioned higher than the film thickness before the flow in. That is, it is desirable that the distance between the upper end of the tapered surface 92 and the surface 41 of the disk portion 44 is greater than several hundred microns. This allows the entire plasma raw material 1 to flow in while touching the tapered surface 92, thereby achieving even greater effectiveness. Of course, these dimensions are merely examples, and specific values ​​are not limited. Furthermore, the specific shape of the tapered surface 92 is not limited.

[0148] FIG. 14 is a schematic diagram showing variations of the abutment members. Similar to the abutment member 90, the abutment member 95 has a tapered surface 92 on the lower left, but no tapered surface on the lower right. The abutment members 96-99 each have a flat tapered surface 110 on the upstream side (left side) of the rotation of the rotor 20. The tapered surfaces 110 of the abutment members 96 and 97 are tapered surfaces with a small height, while the tapered surfaces 110 of the abutment members 98 and 99 are tapered surfaces extending over the entire left side surface. Furthermore, the abutment members 96 and 98 also have a tapered surface on the right side with the same shape as the left side, while the abutment members 97 and 99 do not have a tapered surface on the right side.

[0149] The flat tapered surface 110 further reduces the hydraulic pressure that the abutting member 90 receives. Furthermore, by not having a tapered surface on the right side, it is possible to reduce the time and cost required to process the abutting member. Abutting members of any shape other than those in this example may also be used.

[0150] <Other Embodiments> The present technology is not limited to the above-described embodiments, and various other embodiments can be realized. [Rotation of Contact Member] The contact member may rotate in conjunction with the rotation of the rotating body 20. For example, in FIG. 12A , when the disk portion 70 rotates counterclockwise, the roller 82 rotates clockwise accordingly. Also, in FIG. 3 , it is possible to adopt either a configuration in which the sphere 46 rolls or a configuration in which the sphere 46 does not roll. The rotation of the contact member reduces the frictional force generated between the contact member and the surface 41 of the disk portion 44, thereby suppressing wear of the contact member and the disk portion 44. Furthermore, it is possible to smoothly rotate the rotating body 20.

[0151] [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.

[0152] [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.

[0153] The configurations of the light source device, plasma raw material, plasma generation mechanism, rotor, skimmer, contact member, cylindrical body, elastic body, projectile body, groove portion, and tapered surface described with reference to the drawings are merely one embodiment, and can be arbitrarily modified within the scope of the present technology. In other words, any other configuration for implementing the present technology may be adopted.

[0154] In the present disclosure, when the word "approximately" is used, this is used merely to facilitate understanding of the explanation, and there is no special meaning in the use or non-use of the word "approximately." 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," "triangular," "rectangular," "square," "rectangular," "polygonal," "circular," "semicircular," "trapezoid," "flat," "curved," "cylindrical," "conical," "pyramidal," "disk," "cubic," "rectangular," "spherical," "cylindrical," "bullet-shaped," "ring-shaped," "cone-shaped," "frame-shaped," etc., are defined as "substantially center," "substantially central," "substantially uniform," "substantially equal," "substantially the same," "substantially perpendicular," etc. The concept includes "intersecting," "substantially parallel," "substantially symmetrical," "substantially extending," "substantially axial," "substantially triangular," "substantially rectangular," "substantially square," "substantially rectangular," "substantially polygonal," "substantially circular," "substantially semicircular," "substantially trapezoidal," "substantially planar," "substantially curved," "substantially cylindrical," "substantially conical," "substantially pyramidal," "substantially disk-shaped," "substantially cubic," "substantially rectangular," "substantially spherical," "substantially cylindrical," "substantially bullet-shaped," "substantially ring-shaped," "substantially cone-shaped," "frame-shaped," and the like. For example, the term "perfectly centered," "perfectly central," "perfectly uniform," "perfectly equal," "perfectly the same," "perfectly orthogonal," "perfectly parallel," "perfectly symmetrical," "perfectly extended," "perfectly axial," "perfectly triangular," "perfectly rectangular," "perfectly square," "perfectly rectangular," "perfectly polygonal," "perfectly circular," "perfectly semicircular," "perfectly trapezoidal," "perfectly flat," "perfectly curved," "perfectly cylindrical," "perfectly conical," "perfectly pyramidal," "perfectly disk-shaped," "perfectly cubic," "perfectly rectangular," "perfectly spherical," "perfectly cylindrical," "perfectly bullet-shaped," "perfectly ring-shaped," "perfectly cone-shaped," "perfectly frame-shaped," etc. are also included. Therefore, even if the word "approximately" is not added, the term may include a concept expressed by adding "approximately."On the other hand, when a state is expressed with the word "abbreviated," it does not necessarily mean that the complete state is excluded.

[0155] 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.

[0156] 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.

[0157] DESCRIPTION OF SYMBOLS 1... Plasma raw material 6, 67... Plasma generation mechanism 8... Beam source 20, 68, 69... Rotating body 21, 79, 80... Raw material container 40, 66, 74, 81... Skimmer 41... Surface 43, 85... Side 44, 70, 72... Disk portion 46... Sphere 47, 76... Cylinder 48, 83... Elastic body 52... Flat surface 55... Projectile body 58, 62 to 65... Groove portion 82... Roller 90, 95 to 99... Contact member 91... XY plane 92, 110... Tapered surface 100... Light source device

Claims

1. A light source device that utilizes irradiation of an energy beam to convert a liquid raw material into plasma and extract radiation, comprising: a beam source that irradiates the energy beam; a first rotor having an irradiation surface to which the liquid raw material adheres and which is irradiated with the energy beam; a contact member that contacts the irradiation surface; and a support member that supports the contact member so that the contact member can move in a direction perpendicular to the irradiation surface, the contact member being pressed against the irradiation surface, and a film thickness adjustment mechanism whose cross-sectional area in a plane parallel to the irradiation surface increases from the contact position of the contact member and the irradiation surface toward the contact member.

2. A light source device according to claim 1, wherein the contact member is a second rotating body having a central axis which is an axis along which the contact member can move.

3. A light source device according to claim 2, wherein the contact member has a spherical shape.

4. A light source device according to claim 2, wherein the contact member has a bullet-like shape, and a tip of the contact member contacts the irradiation surface.

5. A light source device according to claim 1, wherein the contact member has a cylindrical shape and a side surface of the contact member contacts the irradiation surface.

6. A light source device according to claim 1 or 2, wherein the support member has an elastic body that presses the contact member against the irradiation surface.

7. A light source device according to claim 1 or 2, wherein the support member supports the contact member so as to be movable in the direction of gravity, and the contact member is pressed against the irradiation surface by the weight of the contact member itself.

8. A light source device according to claim 1 or 2, wherein the first rotating body has a disk shape consisting of a circular first surface, a circular second surface opposite to the first surface, and a side surface.

9. A light source device according to claim 8, wherein the irradiation surface is the first surface.

10. A light source device according to claim 8, wherein the irradiation surface is the side surface.

11. A light source device according to claim 1 or 2, wherein a groove is formed on the irradiation surface, the energy beam is irradiated onto the groove, and the abutment member abuts against the groove.

12. A light source device according to claim 11, wherein the groove portion has the same shape as the contact member.

13. A light source device according to claim 11, wherein the cross section of the groove portion has a shape different from the cross section of the contact member.

14. A light source device according to claim 11, wherein the groove has a cross section having at least one of the following shapes: triangular, rectangular, semicircular, and trapezoidal.

15. A light source device according to claim 1 or 2, wherein the cross-sectional area of ​​the contact member in a plane perpendicular to the direction of rotation of the first rotating body increases toward the downstream side of the rotation.

16. A light source device according to claim 15, wherein the abutting member has a flat tapered surface on the upstream side of the rotation of the first rotating body.

17. A light source device according to claim 15, wherein the abutting member has a curved tapered surface on the upstream side of the rotation of the first rotating body.

18. A light source device according to claim 1 or 2, wherein the abutment member rotates in conjunction with the rotation of the first rotating body.

19. A light source device according to claim 1 or 2, wherein the support member has a cylindrical shape.

20. A light source device according to claim 1 or 2, further comprising a container capable of containing the liquid raw material, and the rotating body is immersed in the liquid raw material contained in the container.

21. A light source device according to claim 1 or 2, wherein the energy beam is a laser beam.

22. A light source device according to claim 1 or 2, wherein the radiation is extreme ultraviolet light or X-rays.

23. A light source device 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.

24. A film thickness adjustment mechanism comprising: a first rotating body having an adhesion surface onto which liquid raw material adheres; a contact member that contacts the adhesion surface; and a support member that supports the contact member so that the contact member can move in a direction perpendicular to the adhesion surface, wherein the contact member is pressed against the adhesion surface, and the cross-sectional area in a plane parallel to the adhesion surface increases from the contact position of the contact member and the adhesion surface toward the contact member.

Images