Light source device

Abstract

To provide a light source device capable of suppressing an influence of a debris.SOLUTION: A light source device according to one embodiment of the present invention includes a beam intake section, a plate member, a raw material supply section, and a radiation extraction section. The beam intake section captures an energy beam. The plate member has a front surface and a back surface, is arranged at a position where the taken-in energy beam is incident on the surface, and rotates with a direction perpendicular to the surface as a rotation axis direction. The raw material supply section generates plasma by supplying a plasma raw material to an incident region on the surface where the energy beam is incident. The radiation extraction section extracts radiation from the generated plasma and emits it. In addition, the plate member is arranged such that a normal axis in the incident region of the surface comes off from an interaxial region formed between an incident axis of the energy beam incident on the incident region and an exit axis of the radiation extracted from the plasma.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a light source device that can be used to emit X-rays, extreme ultraviolet light, and the like. [Background technology]

[0002] Traditionally, X-rays have been used for medical, industrial and research purposes. 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 non-destructive testing to observe the inside of materials such as structures and welds, and for non-destructive tomographic testing. In research fields, 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] X-rays can be generated using an X-ray tube, which has a pair of electrodes (anode and cathode) inside it. When a current is passed through the cathode filament to heat it, and a high voltage is applied between the anode and cathode, negative thermions generated from the filament collide at high speed with a target on the surface of the anode, generating X-rays from the target. There is also known a technique for extracting high-intensity X-rays in an X-ray tube by using a liquid metal jet as the target on the anode side and irradiating this target with an electron beam.

[0004] Extreme ultraviolet light (hereinafter also referred to as "EUV (Extreme Ultra Violet) 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 been used as exposure light in recent years. Here, the substrate of the mask for EUV lithography, on which the 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. Then, an EUV mask is constructed by patterning a material that absorbs radiation with a wavelength of 13.5 nm on the multilayer film.

[0005] The size of unacceptable defects in EUV masks is significantly smaller than that in 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 allows for defect detection with a resolution better than 10 nm.

[0006] Generally, EUV light source devices include DPP (Discharge Produced Plasma) light source devices, LDP (Laser Assisted Discharge Produced Plasma) light source devices, and LPP (Laser Produced Plasma) light source devices. DPP-type EUV light source devices apply a high voltage between electrodes to which a discharge gas containing EUV-radiating species (gas-phase plasma raw material) is supplied, generating a high-density, high-temperature plasma through discharge, and utilize the extreme ultraviolet light emitted from this 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 laser beam) such as a laser beam to vaporize the raw material, and then generates high-temperature plasma by discharge.

[0008] The LPP light source device focuses laser light onto droplets of tin (Sn) or lithium (Li), which are the target material for EUV radiation, and excites the target material to generate plasma.

[0009] In this way, it is possible to use a DPP type (LDP type) or LPP type light source device as an EUV light source device that generates EUV light in the soft X-ray region. On the other hand, in EUV light source devices, DPP type (LDP type) devices ultimately generate plasma by discharge between electrodes, so debris caused by the EUV raw material is likely to be generated. The LPP method targets tiny tin droplets, the EUV raw material, and focuses the excitation laser light onto them, so the light source structure is complex.It is also difficult to stably drop and supply tin droplets, making it difficult to stably generate EUV light.

[0010] Patent Document 1 proposes a method of obtaining X-rays by applying a liquid target material for X-ray generation to a disk-shaped rotating body and irradiating the applied liquid material with an energy beam (laser beam). This method makes it possible to obtain high-intensity X-rays with a relatively simple configuration. When the method described in Patent Document 1 is applied to an EUV light source device, it corresponds to the so-called LPP method, but there is no need to supply the liquid EUV raw material as droplets. This makes it easy to supply the EUV raw material and enables the liquid EUV raw material to be reliably irradiated with a laser beam, making it possible to obtain EUV radiation with a device with a relatively simple configuration. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] Patent No. 6658324 Summary of the Invention [Problem to be solved by the invention]

[0012] In the light source devices that emit X-rays, EUV light, etc., it is important to suppress the influence of debris.

[0013] In view of the above circumstances, an object of the present invention is to provide a light source device that can suppress the influence of debris. [Means for solving the problem]

[0014] In order to achieve the above object, a light source device according to one aspect of the present invention includes a beam intake section, a plate member, a raw material supply section, and a radiation extraction section. The beam intake section intakes an energy beam. The plate member has a front surface and a back surface, is disposed at a position where the captured energy beam is incident on the front surface, and rotates around a direction perpendicular to the front surface as a rotation axis. The raw material supply unit generates plasma by supplying plasma raw material to an incident region on the surface where the energy beam is incident. The radiation extraction section extracts and emits radiation from the generated plasma. Furthermore, the plate member is positioned so that the normal axis at the incident region of the surface is offset from the inter-axial region formed between the incident axis of the energy beam incident on the incident region and the exit axis of the radiation extracted from the plasma.

[0015] In this light source device, plasma raw material is supplied to the surface of a rotatable plate member and an energy beam is irradiated onto the surface, thereby generating plasma and emitting radiation. The plate member is arranged so that the normal axis in the incident region where the energy beam is incident is offset from the inter-axial region between the incident axis of the energy beam and the emission axis of the radiation. This provides a light source device that can suppress the influence of debris that accompanies plasma generation.

[0016] The light source device may further include a chamber that accommodates the plate member. In this case, the beam capture unit may have an incident chamber connected to the chamber and an incident-side aperture that allows the energy beam to enter the chamber from the incident chamber. The plate member may be positioned such that the normal axis is deviated from an opening of the incident-side aperture.

[0017] The light source device may further include a chamber that houses the plate member. In this case, the radiation extraction unit may include an exit chamber connected to the chamber and an exit aperture that allows the radiation from the chamber to enter the exit chamber. The plate member may be configured such that the normal axis is deviated from an opening of the exit aperture.

[0018] The light source device may further include a gas supply unit that blows gas in a direction from the inter-axis region toward the normal axis so that the normal axis is located downstream of the inter-axis region.

[0019] The chamber may be maintained at a reduced pressure compared to the entrance chamber.

[0020] A gas may be supplied into the injection chamber to increase the pressure therein.

[0021] The chamber may be maintained at an atmosphere that is reduced in pressure compared to the emission chamber.

[0022] A gas may be supplied into the emission chamber to increase the pressure therein.

[0023] The inter-axial region may include a three-dimensional region formed by a trajectory when a two-dimensional region between the incident axis and the exit axis on a plane containing the incident axis and the exit axis is moved along the normal direction of the plane.

[0024] At least one of the angle between the entrance axis and the normal axis or the angle between the exit axis and the normal axis may be configured to be in the range of 30 degrees to 60 degrees.

[0025] The angle between the entrance axis and the normal axis and the angle between the exit axis and the normal axis may each be configured to be in the range of 30 degrees to 60 degrees.

[0026] The beam capture section may have an incident-side protrusion that protrudes toward the incident region and has the incident-side aperture provided at a tip of the protruding side.

[0027] The incident-side protrusion may have a cone shape whose cross-sectional area decreases toward the protruding side.

[0028] The radiation extraction section may have an emission-side protrusion that protrudes toward the incident region and has the emission-side aperture provided at a tip of the protruding side.

[0029] The emission-side protrusion may have a cone shape whose cross-sectional area decreases toward the protrusion side.

[0030] The light source device may further include a voltage application unit that applies a voltage to the emission-side protrusion.

[0031] The radiation may be X-rays or extreme ultraviolet light.

[0032] The light source device may further include a thickness adjustment mechanism that adjusts the thickness of the plasma raw material supplied to the surface. [Effects of the Invention]

[0033] As described above, according to the present invention, it is possible to suppress the effects of debris. 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 applicable. [Brief explanation of the drawings]

[0034] [Figure 1] 1 is a schematic diagram illustrating an example of the configuration of a light source device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a schematic diagram showing a configuration example of a raw material supply mechanism. [Figure 3] 10A and 10B are schematic diagrams showing other configuration examples of a container applicable to a light source device. [Figure 4] FIG. 2 is a schematic diagram for explaining the arrangement of a rotating body. [Figure 5] FIG. 2 is a schematic diagram for explaining the inter-axis region in detail. [Figure 6] FIG. 10 is a schematic diagram showing another example of the arrangement of the rotating body. DETAILED DESCRIPTION OF THE INVENTION

[0035] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0036] [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 one embodiment of the present invention. FIG. 1 is a diagram showing a schematic cross section of the light source device 1 taken horizontally at a position at a predetermined height from the installation surface, as viewed from above. In FIG. 1, in order to make it easier to understand the configuration and operation of the light source device 1, cross sections of parts that do not need to be explained are omitted. In the following explanation, the X direction will 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-to-back 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 upward side, and the negative side is the downward side). Of course, the application of the present technology is not limited to the direction in which the light source device 1 is used.

[0037] The light source device 1 is an LPP type light source device, and is capable of emitting radiation R ranging from hard X-rays with wavelengths of 30 nm or less to soft X-rays (including EUV light), for example. Therefore, the light source device 1 can be used as an X-ray generator or an EUV light source device (EUV radiation generator). Of course, the present technology can also be applied to light source devices that emit radiation in other wavelength bands.

[0038] The light source device 1 includes a housing 2, a vacuum chamber 3, an energy beam entrance chamber 4, a radiation exit chamber 5, a raw material supply mechanism 6, and a control unit . The housing 2 is configured so that its outer shape is roughly cubic. The housing 2 has an exit hole 8 formed on the front surface, an entrance hole 9 formed on the right side surface, two through holes 10 and 11 formed on the rear surface, and a through hole 12 formed on the left side surface. The material of the housing 2 is not limited, and for example, a metal housing is used.

[0039] In this embodiment, the emission axis EA of the radiation R is set to pass through the emission hole 8 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 8. In this embodiment, the incidence axis IA of the energy beam EB is set so as to extend obliquely leftward from the incidence hole 9 on the right side surface toward the rear side. 1, a beam source 13 that emits an energy beam EB is installed outside the housing 2. The beam source 13 is installed so that the energy beam EB enters the inside of the housing 2 along an incident axis IA. An electron beam or a laser beam can be used as the energy beam EB. The beam source 13 may be configured in any way that can emit the energy beam EB.

[0040] The vacuum chamber 3, the energy beam incident chamber (hereinafter simply referred to as the incident chamber) 4, and the radiation exit chamber (hereinafter simply referred to as the exit chamber) 5 are spatially connected to one another. That is, the vacuum chamber 3 and the incident chamber 4 are linked to one another. Similarly, the vacuum chamber 3 and the exit chamber 5 are linked to one another. In this embodiment, the vacuum chamber 3, the entrance chamber 4, and the exit chamber 5 are formed by the chamber main body 14, an outer protrusion 15 that protrudes forward from the front surface of the chamber main body 14, and two inner protrusions 16 and 17 that protrude inward from the inner surface of the chamber main body 14. The chamber body 14, the outer protrusion 15, and the two inner protrusions 16 and 17 are made of, for example, a metal material.

[0041] The chamber main body 14 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, respectively. The chamber body 14 is also disposed so that the front right corner between the front surface and the right side surface is positioned on the incident axis IA of the energy beam EB.

[0042] 1, an emission hole 18 is formed in the front surface of the chamber body 14. The emission hole 18 is formed at a position aligned with the emission hole 8 in the front surface of the housing 2 on the emission axis EA of the radiation R. An outer protrusion 15 is configured to protrude forward from the periphery of the emission hole 18 of the chamber body 14. The outer protrusion 15 is configured to protrude farther forward than the emission hole 8 of the housing 2 so as to be inscribed within the emission hole 8 of the housing 2. Furthermore, an inner protrusion 16 is formed on the inner side of the chamber body 14 so as to protrude inward from the periphery of the emission hole 18 . The space surrounded by the outer protrusion 15 and the inner protrusion 16 functions as the emission chamber 5. The outer protrusion 15 and the inner protrusion 16, which are members that constitute the emission chamber 5, can also be called the emission chamber. The outer protrusion 15 and the inner protrusion 16 may be formed integrally with the chamber body 14 or may be formed separately and then connected to the chamber body 14 .

[0043] 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 the cross-sectional area is large in the center in the direction of the exit axis EA of the radiation R and becomes smaller as it approaches the front and rear ends. In other words, the exit chamber 5 has a shape that narrows as it approaches the front and rear ends.

[0044] An entrance window 19 is formed in the front right corner of the chamber body 14. The entrance window 19 is formed at a position aligned with the entrance hole 9 on the right side surface of the housing 2 on the entrance axis IA of the energy beam EB. Furthermore, an inner protrusion 17 is configured on the inner side of the right front corner of the chamber body 14 so as to protrude from a position surrounding the entrance window 19 along the direction of the entrance axis IA of the energy beam EB. Of the internal space of chamber main body 14, the space surrounded by inner protrusion 17 functions as incident chamber 4. Inner protrusion 17 and the front right corner of chamber main body 14, which constitute incident chamber 4, can also be called the incident chamber itself. The inner protrusion 17 may be integrally formed with the chamber body 14 or may be formed separately and then connected to the chamber body 14 .

[0045] 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 as it approaches the end on the inner side of the chamber body 14 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 as it approaches the end on the inner side.

[0046] Of the internal space of the chamber body 14, the space excluding the internal space of the inner protrusion 16 which functions as the emission chamber 5 and the internal space of the inner protrusion 17 which 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. As shown in FIG. 1, the chamber body 14 has a portion that protrudes from the housing 2 to the outside through a through-hole 12 on the left side of the housing 2, and its tip is connected to an exhaust pump 20. The vacuum chamber 3 is evacuated by the exhaust pump 20, reducing the pressure in the vacuum chamber 3. This suppresses the attenuation of the radiation R generated in the vacuum chamber 3. The inside of the vacuum chamber 3 does not necessarily have to be a vacuum atmosphere as long as it is a reduced pressure atmosphere relative to the entrance chamber 4 and the exit chamber 5. Also, an inert gas may be supplied into the vacuum chamber 3. The specific configuration of the exhaust pump 20 is not limited, and any pump such as a vacuum pump may be used.

[0047] The raw material supply mechanism 6 is a mechanism for generating plasma P in the plasma generation region 21 in the vacuum chamber 3 and emitting radiation R (X-rays, EUV light). The raw material supply mechanism 6 is disposed inside the vacuum chamber 3 and includes a disk-shaped rotor 22 for supplying raw material, and a container 24 for accommodating a liquid-phase plasma raw material (radiation raw material) 23. 1, an incident area 25 onto which the energy beam EB is incident is set on a disk-shaped rotor 22. The rotor 22 is disposed in the vacuum chamber 3 so that the incident area 25 is located at the intersection of the incident axis IA and the exit axis EA. Plasma raw material 23 is supplied to an incident region 25 of the rotor 22, and an energy beam EB is incident on the incident region 25, thereby generating plasma P. The region (space) in the vacuum chamber 3 where the plasma P is generated is the plasma generation region 21. Therefore, the plasma generation region 21 is a region corresponding to the position of the incidence region 25 of the rotor 22. Other details of the raw material supply mechanism 6 will be described later.

[0048] The control unit 7 controls the operation of each of the components of the light source device 1. For example, the control unit 7 controls the operation of the beam source 13 and the exhaust pump 20. The control unit 7 also controls the operation of various motors, a plasma raw material circulation device, an external voltage source, and the like, which will be described later. The control unit 7 has hardware circuits necessary for a computer, such as a CPU, memory (RAM, ROM), etc. 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 implemented by a programmable logic device (PLD) such as a field programmable gate array (FPGA), or other devices such as an application specific integrated circuit (ASIC). In FIG. 1, the control unit 7 is illustrated as a schematic functional block, but the position where the control unit 7 is configured may be designed arbitrarily. In this embodiment, the CPU of the control unit 7 executes the program according to this embodiment, thereby performing the plasma generation method and the radiation emission method according to this embodiment.

[0049] The various chambers that make up the light source device 1 and the raw material supply mechanism 6 will be described in detail below.

[0050] [Incidence chamber] The incident chamber 4 is defined by an inner protrusion 17 at the front right corner of the chamber body 14. An incident window 19 is disposed at the front right corner of the chamber body 14, and the energy beam EB emitted from the beam source 13 passes through the incident window 19 and enters the interior of the incident chamber 4 along the incident axis IA. The incidence axis IA of the energy beam EB can also be said to be the optical axis (principal axis) of the energy beam EB incident on the interior of the incidence chamber 4.

[0051] The entrance window 19 is made of a material that is transmissive to the energy beam EB, and is designed to have a thickness that can withstand the pressure difference between the inside and outside of the entrance chamber 4 . When the energy beam EB is an electron beam, a metal film such as titanium or aluminum can be used. When the energy beam EB is a laser beam, for example, a glass material (quartz glass) can be used. Alternatively, any material that can transmit the energy beam EB may be used.

[0052] The inner protrusion 17 protrudes toward an incident region 25 on the surface 22a of the rotor 22, and an incident-side aperture 26 is formed at the tip of the protruding side. The entrance aperture 26 is arranged to be aligned with the entrance window 19 on the entrance axis IA of the energy beam EB. The entrance-side aperture 26 allows the energy beam EB to enter the vacuum chamber 3 from the entrance chamber 4. That is, the energy beam EB traveling along the entrance axis IA from the entrance window 19 passes through the entrance-side aperture 26 and enters the rotor 22 arranged in the vacuum chamber 3.

[0053] Inside the injection chamber 4, a capture mechanism is arranged to capture the scattered plasma raw material 23 and debris. 1, the capture mechanism is a rotary window 27, which is a plate-shaped rotating member that transmits the energy beam EB and captures the plasma raw material 23 and debris. The rotary window 27 is configured in the shape of, for example, a disk. A rotating shaft of a motor (not shown) is attached to the center of the rotating window 27. The motor rotates the rotating shaft, thereby rotating the rotating window 27. The motor is controlled and driven by the control unit 7. The motor is formed outside the housing 2, and the rotating shaft is connected to the rotary window 27 through a through-hole (not shown) formed in the housing 2 and the chamber main body 14. A mechanical seal is used when the rotating shaft is introduced into the chamber main body 14, and rotation of the rotary window 27 is permitted while maintaining the atmosphere inside the injection chamber 4 (a gas atmosphere described below). In addition, the rotation axis for rotating the rotating window 27 is positioned at a position offset from the incident axis IA of the energy beam EB, which allows the energy beam EB to travel through the beam transmission region of the rotating window 27 without being interfered with by the rotation axis of the rotating window 27. By rotating the rotating window 27, it is possible to increase the effective area of ​​the beam transmission region of the rotating window 27, thereby extending the life of the rotating window 27 and reducing the frequency of replacement of the rotating window 27. Countermeasures for the scattered plasma raw material 23 and debris will be explained in detail later.

[0054] 1, a gas injection path 28 is installed in chamber body 14 so as to connect to incidence chamber 4. Gas is supplied into incidence chamber 4 via gas injection path 28 from a gas supply device (not shown). The gas to be supplied is a gas that has a high transmittance to the energy beam EB, and for example, a rare gas such as argon (Ar) or helium (He) is used. The gas is supplied to increase the pressure inside incidence chamber 4. That is, by supplying gas into incidence chamber 4 from gas injection path 28, the internal pressure of incidence chamber 4 can be maintained at a pressure that is sufficiently higher than the internal pressure of vacuum chamber 3. Inner protrusion 17 has a cone shape whose cross-sectional area decreases toward the protrusion side (the side where entrance-side aperture 26 is formed). At its tip, entrance-side aperture 26 is provided. This configuration is advantageous for supplying gas to increase the internal pressure of entrance chamber 4. Furthermore, by configuring the inner protrusion 17 in a cone shape, it is possible to reduce the space occupied by the inner protrusion 17 within the chamber body 14, thereby improving the degree of freedom in the layout design of other components, etc. As a result, it is possible to miniaturize the device.

[0055] In this embodiment, the incident chamber 4, the inner protrusion 17, the incident-side aperture 26, etc., form a beam intake section that intakes the energy beam. In this embodiment, the inner protrusion 17 functions as an incident side protrusion.

[0056] [Exit chamber] The exit chamber 5 has a cone shape with the exit axis EA as its central axis, and a utilization device such as a mask inspection device is connected to the front end (the front end of the outer protrusion 15). In the example shown in Fig. 1, an application chamber 30 is connected as a chamber that forms part of the utilization device. The pressure inside the application chamber 30 may be atmospheric pressure. If necessary, the inside of the application chamber 30 may be purged by introducing a gas (e.g., an inert gas) through the gas injection path 31. The gas inside the application chamber 30 may be exhausted by an exhaust means (not shown).

[0057] 1, a gas injection path 32 is provided in the outer protrusion 15 so as to connect to the emission chamber 5. Gas is supplied into the emission chamber 5 via the gas injection path 32 from a gas supply device (not shown). The gas to be supplied is a gas that has a high transmittance to the radiation R, and for example, a rare gas such as argon or helium is used. Argon and helium can be used as gases that have high transmittance for both the energy beam EB and the radiation R. Therefore, the same gas may be supplied to both the entrance chamber 4 and the exit chamber 5. In this case, the gas supply device can be shared, which simplifies the device. Of course, different gases may be supplied to the entrance chamber 4 and the exit chamber 5. The gas is supplied to increase the pressure inside the emission chamber 5. That is, by supplying gas into the emission chamber 5 from the gas injection path 32, the internal pressure of the emission chamber 5 can be maintained at a pressure sufficiently higher than the internal pressure of the vacuum chamber 3.

[0058] A collector (condensing mirror) 33 is disposed inside the exit chamber 5 to guide and condense the radiation R that has entered the exit chamber 5 into the utilization device (inside the application chamber 30). In Fig. 1, the components of the radiation R that enter the exit chamber 5 and are condensed are shown by hatching. The outer surface of the collector 33 contacts the inner surface of the exit chamber 5 (the inner surface of the outer protrusion 15) for cooling and alignment purposes. For example, a single-shell grazing incidence reflector is used as the collector 33. The main body of the collector 33 is made of a metal member (for example, aluminum (Al), nickel (Ni), or stainless steel).

[0059] The reflective coating on the inner reflective surface of the collector 33 is optional, but a suitable reflective coating material for reflecting the radiation R is, for example, ruthenium (Ru). Instead of having a structure in which the collector 33 has a body coated with expensive Ru, the body may be made of glass (silicon dioxide: SiO2) and the inside may be polished to form a radiation reflecting surface. Although the reflectivity of the reflective surface of this glass collector is lower than that of a collector made of a metal member with a Ru coating, the material cost is much lower than that of the Ru-coated collector, and frequent replacement is possible.

[0060] The inner protrusion 16 that constitutes the exit chamber 5 protrudes toward the incident region 25 on the surface 22a of the rotor 22, and an exit-side aperture 34 is formed at the tip of the protruding side. The exit aperture 34 is arranged on the exit axis EA of the radiation R so as to be aligned with the exit hole 18 of the chamber body 14 and the exit hole 8 of the housing 2. The exit aperture 34 allows the radiation R to enter the exit chamber 5 from the vacuum chamber 3. That is, a portion of the radiation R emitted from the plasma P passes through the exit aperture 34 and enters the collector 33. The radiation R is guided by the collector 33 and collected in the application chamber 30. By appropriately designing the opening area of ​​the exit aperture 34, it is possible to control the divergence angle of the radiation R incident on the collector 33. The emission axis EA of the radiation R can also be said to be the optical axis (main axis) of the radiation R taken into the extraction chamber 5 from the plasma P.

[0061] The inner protrusion 16 has a cone shape whose cross-sectional area decreases toward the protrusion side (the side where the output aperture 34 is formed). Therefore, the inner protrusion 16 can also be called a collector cone. The cone-shaped internal protrusion 16 has an exit aperture 34 at its tip, which is advantageous for supplying gas to increase the internal pressure of the exit chamber 5 . Furthermore, by configuring the inner protrusion 16 in a cone shape, it is possible to reduce the space occupied by the inner protrusion 16 within the chamber body 14, thereby improving the degree of freedom in the layout design of other components, etc. As a result, it is possible to miniaturize the device.

[0062] As shown in FIG. 1, a filter membrane 35 is provided between the emission chamber 5 and the application chamber 30 . The filter film 35 serves to physically separate (physically separate the spaces) the plasma generation region 21 in the vacuum chamber 3 from the application chamber 30, and prevents the scattered plasma raw material 23 and debris from entering the application chamber 30 (this point will be explained in more detail later). The filter film 35 is made of a material that transmits the radiation R generated in the plasma generation region 21. When the radiation R is X-rays, the filter film 35 is made of, for example, a beryllium thin film that has a very high transmittance for X-rays. When the radiation R is EUV light, the filter film 35 is made of, for example, zirconium (Zr).

[0063] Although gas is supplied into the emission chamber 5, the atmosphere is reduced pressure because it is spatially connected to the vacuum chamber 3. On the other hand, the pressure inside the application chamber 30 may be atmospheric pressure as described above. In this case, a pressure difference occurs between the emission chamber 5 and the application chamber 30. Therefore, the thickness of the filter film 35 is set to a value that can withstand this pressure difference. In other words, the filter film 35 is configured so as not to destroy the reduced pressure atmosphere in the emission chamber 5, which is spatially connected to the vacuum chamber 3.

[0064] Inside the emission chamber 5, a shielding member (central shielding) 36 is arranged. The shielding member 36 is arranged on the emission axis EA of the radiation R so as to be aligned with the emission hole 18 of the chamber body 14, the emission hole 8 of the housing 2, and the filter film 35. Among the radiation R emitted from the plasma P and entering the exit chamber 5, there may be radiation components that are not collected by the collector 33 and travel within the exit chamber 5. At least a portion of these uncollected radioactive components travels while diverging. Such radiation components are usually not used in the utilization device and are often unnecessary. In this embodiment, the shielding member 36 can block radiation components that are not collected by the collector 33 .

[0065] In this embodiment, the extraction chamber 5, the outer protrusion 15, the inner protrusion 16, the exit aperture 34, etc. constitute a radiation extraction section that extracts and emits radiation from the generated plasma. In this embodiment, the inner protrusion 16 also functions as an emission side protrusion.

[0066] [Raw material supply mechanism] FIG. 2 is a schematic diagram showing an example of the configuration of the raw material supply mechanism 6. As shown in FIG. Fig. 2 shows the rotor 22 and the container 24 as viewed from the direction of arrow A in Fig. 1. Therefore, Fig. 2 shows the surface 22a side of the rotor 22.

[0067] As shown in FIGS. 1 and 2, the raw material supply mechanism 6 includes a disk-shaped rotor 22, a container 24, a motor 38, a rotating shaft 39, a skimmer 40, and a plasma raw material circulation device 41.

[0068] The disk-shaped rotor 22 has a front surface 22a and a back surface 22b, and an incident area 25 onto which the energy beam EB is incident is set at a predetermined position on the front surface 22a. In other words, of the two main surfaces of the rotor 22, the main surface onto which the incident area 25 onto which the energy beam EB is incident is set is the front surface 22a. The main surface on the opposite side is the back surface 22b. The rotor 22 is made of a high melting point metal such as tungsten (W), molybdenum (Mo), or tantalum (Ta). A portion of the lower side of the rotor 22 is immersed in plasma raw material 23 stored in a container 24 .

[0069] When X-rays are emitted as the radiation R, an X-ray raw material is used as the plasma raw material 23. The X-ray raw material is a metal that is liquid at room temperature, and for example, gallium (Ga) or a gallium alloy such as Galinstan (registered trademark), which is a eutectic alloy of gallium, indium (In) and tin (Sn), can be used. When EUV light is emitted as the radiation R, an EUV raw material is used as the plasma raw material 23. As the raw material for emitting EUV light, for example, liquid tin (Sn) or lithium (Li) is used. Since Sn and Li are solid at room temperature, a temperature control means (not shown) is provided in the container 24. For example, when the EUV raw material is Sn, the container 24 is maintained at a temperature equal to or higher than the melting point of Sn.

[0070] A rotation shaft 39 of a motor 38 is connected to the center of the rear surface 22b of the rotor 22. The operation of the motor 38 is controlled by the control unit 7, and the rotor 22 is rotated via the rotation shaft 39. The rotation shaft 39 is disposed so as to extend in a direction perpendicular to the front surface 22a of the rotor 22. Therefore, the rotor 22 rotates in the direction perpendicular to the front surface 22a. The rotating shaft 39 passes through the through-hole 10 in the housing 2 and is introduced into the vacuum chamber 3 via a mechanical seal 42. The mechanical seal 42 allows the rotating shaft 39 to rotate while maintaining the reduced pressure atmosphere inside the vacuum chamber 3.

[0071] Rotor 22 rotates around rotation shaft 39 with a portion of the lower side of rotor 22 immersed in plasma raw material 23 stored in container 24. As a result, plasma raw material 23 is pulled up from the raw material storage portion of container 24 and transported so that it fits onto surface 22a of rotor 22 due to its wettability with surface 22a. Therefore, motor 38 and rotation shaft 39 function as a raw material supply unit that applies raw material to at least a portion of surface 22a of rotor 22. 2, in this embodiment, an incident region 25 onto which the energy beam EB is incident is set near the periphery of the surface 22a of the rotor 22. The configuration and operation of the raw material supply unit (motor 38 and rotating shaft 39) are appropriately designed so that the plasma raw material 23 is supplied to this incident region 25.

[0072] Skimmer 40 is provided at a predetermined position on the periphery of rotor 22 as a film thickness adjusting member for adjusting the film thickness of plasma raw material 23 supplied onto surface 22a of rotor 22 to a predetermined film thickness. The skimmer 40 is, for example, a structure having a channel structure, and is arranged with a predetermined gap therebetween so as to sandwich the rotor 22. The skimmer 40 functions as a scraper that scrapes off part of the plasma raw material 23 applied to the surface 22a of the rotor 22.

[0073] The distance between surface 22a of rotor 22 and skimmer 40 corresponds to the film thickness of plasma raw material 23 in incident region 25, where energy beam EB is incident, on surface 22a of rotor 22. Skimmer 40 is positioned so that the film thickness of plasma raw material 23 in incident region 25 on surface 22a of rotor 22 can be adjusted to a predetermined film thickness. The distance between surface 22a of rotor 22 and skimmer 40 is set appropriately. As a result, when liquid plasma raw material 23 applied to rotor 22 in the raw material storage portion of container 24 passes through skimmer 40 due to the rotation of rotor 22, the film thickness on rotor 22 is adjusted to a predetermined thickness.

[0074] The plasma raw material 23 on the rotor 22, whose film thickness has been adjusted by the skimmer 40, is transported to the incident region 25 where the energy beam EB is incident as the rotor 22 rotates. That is, the rotation direction of the rotor 22 is the direction in which the plasma raw material 23 on the rotor 22 is transported to the incident region 25 after passing through the skimmer 40. Then, in the incident region 25, the energy beam EB is irradiated onto the plasma raw material 23 on the rotor 22, and plasma P is generated. Skimmer 40 makes it possible to supply plasma raw material 23 almost uniformly to incident region 25. By stabilizing the thickness of plasma raw material 23 in incident region 25, it becomes possible to stabilize the intensity of radiation R emitted from plasma P. In this embodiment, the skimmer 40 realizes a thickness adjustment mechanism that adjusts the thickness of the plasma raw material supplied to the surface.

[0075] The plasma raw material circulation device 41 replenishes the container 24 with plasma raw material 23 as needed when the plasma raw material 23 is consumed in the operation of generating radiation R. The plasma raw material circulation device 41 also functions as a temperature adjustment mechanism (cooling mechanism) for the plasma raw material 23.

[0076] As shown in FIG. 2, plasma raw material circulation device 41 includes raw material inlet pipeline 44, raw material outlet pipeline 45, raw material storage tank 46, raw material drive unit (pump) 47, and temperature adjustment mechanism 48. The raw material storage tank 46 stores the plasma raw material 23 . The raw material inlet pipe 44 and the raw material outlet pipe 45 are installed between the raw material storage tank 46 and the container 24 so as to communicate between the raw material storage tank 46 and the container 24 . Raw material driver 47 is installed in raw material inlet pipeline 44. When raw material driver 47 is driven, plasma raw material 23 stored in raw material storage tank 46 flows out into raw material inlet pipeline 44, making it possible to circulate plasma raw material 23 through a circulation system consisting of raw material storage tank 46, raw material inlet pipeline 44, container 24, and raw material outlet pipeline 45. For example, an electromagnetic pump capable of transporting liquid metal (plasma raw material 23) by magnetic force is used as raw material driver 47. Of course, other types of pumps may also be used.

[0077] In this embodiment, the raw material storage tank 46 and the raw material driving unit 47 are disposed outside the vacuum chamber 3 and also outside the housing 2. A raw material inlet pipe 44 and a raw material outlet pipe 45 extending from the plasma raw material circulation device 41 to the container 24 pass through the through-hole 11 in the housing 2, are introduced into the vacuum chamber 3 via a sealing member 49, and are connected to the container 24. The seal member 49 allows the raw material inlet pipe 44 and the raw material outlet pipe 45 to pass through the vacuum chamber 3 from the outside to the inside while maintaining the reduced pressure atmosphere inside the vacuum chamber 3 .

[0078] Of the plasma raw material 23 applied to the surface 22a of the rotor 22, the portion irradiated with the energy beam EB is consumed. Therefore, in order to stably generate radiation R (X-rays or EUV light) for a long period of time, it is necessary to store a large amount of plasma raw material 23 in the container 24. On the other hand, due to the size of the vacuum chamber 3 of the light source device 1, there are restrictions on the size of the container 24 that can be accommodated inside the vacuum chamber 3, and it is often difficult to store a large amount of plasma raw material 23 in the container 24. Therefore, a raw material storage tank 46 capable of storing a large volume of plasma raw material 23 is installed outside the vacuum chamber 3, and the raw material storage portion of the container 24 can be replenished with plasma raw material 23 via a raw material inlet pipe 44. This allows the amount of plasma raw material 23 in the raw material storage portion of the container 24 to be kept constant for a long period of time, and as a result, the radiation R can be generated stably for a long period of time. That is, plasma raw material circulation device 41 circulates plasma raw material 23 between the raw material storage portion of container 24 and raw material storage tank 46 so that the amount of plasma raw material 23 in the raw material storage portion of container 24 remains constant.

[0079] Furthermore, when the plasma raw material 23 applied to the surface 22a of the rotor 22 is irradiated with the energy beam EB, radiation R is emitted from the plasma raw material 23 (target), and at the same time the rotor 22 itself is heated. This heated rotor 22 exchanges heat with the plasma raw material 23 in the container 24 every time it passes through the raw material storage section of the container 24 in which the plasma raw material 23 is stored. Therefore, if left as is, the temperature of the plasma raw material 23 inside the container 24 will gradually change. If the viscosity of the plasma raw material 23 changes with temperature, the wettability of the plasma raw material 23 with respect to the rotor 22 will change as the temperature of the plasma raw material 23 changes, and the state of adhesion of the plasma raw material 23 to the rotor 22 will change. As a result, the output of the radiation R may also change.

[0080] The plasma raw material circulation device 41 according to this embodiment includes a relatively large raw material storage tank 46 outside the vacuum chamber 3 (outside the housing 2). Therefore, even if plasma raw material 23 whose temperature has changed in the raw material storage portion of container 24 flows into raw material storage tank 46 via raw material discharge pipe 45, the temperature of plasma raw material 23 in raw material storage tank 46 does not change significantly and is kept almost constant. Then, the plasma raw material 23 , which is maintained at a substantially constant temperature, is flowed into the container 24 via the raw material inlet pipe 44 . In this way, by circulating the plasma raw material 23 using the plasma raw material circulation device 41, the temperature of the plasma raw material 23 inside the container 24 is kept almost constant. Therefore, the state of adhesion of the plasma raw material 23 to the rotor 22 is stabilized, and the output of the radiation R can be stabilized.

[0081] Furthermore, the temperature of the plasma raw material 23 in the raw material storage tank 46 may be adjusted by a temperature adjustment mechanism 48 provided inside the raw material storage tank 46 . Because raw material storage tank 46 is installed outside vacuum chamber 3 (outside housing 2), it is possible to use a large-capacity temperature adjustment mechanism 48 that is not affected by the size of vacuum chamber 3. This makes it possible to reliably adjust the temperature of plasma raw material 23 to a predetermined temperature in a short period of time.

[0082] In this way, by using plasma raw material circulation device 41 having temperature adjustment mechanism 48, it is possible to supply plasma raw material 23 to the raw material storage portion of container 24 while maintaining the temperature of plasma raw material 23 constant. For example, suppose a liquid metal whose temperature in its liquid state is lower than room temperature is used as the plasma raw material 23. Even in this case, it is possible to supply the liquid phase plasma raw material 23 to the container 24 while maintaining the temperature lower than room temperature. Furthermore, suppose that a liquid metal whose temperature in its liquid state is higher than room temperature is used as plasma raw material 23. Even in this case, it is possible to supply liquid-phase plasma raw material 23 to container 24 while maintaining the temperature higher than room temperature.

[0083] As shown in FIG. 1, in this embodiment, a radiological diagnostic section 29 is configured in an area spatially connected to the vacuum chamber 3 on the front side of the chamber body . The radiological diagnosis section 29 is configured at a position where the radiation R emitted in a direction different from the emission axis EA of the radiation R is incident. The radiological diagnosis unit 29 is a part that diagnoses the physical state of the radiation R, and is configured, for example, by a detector that detects the presence or absence of the radiation R and a measuring device that measures the output of the radiation.

[0084] In this embodiment, the rotating body 22 realizes a plate member that has a front surface and a back surface, is positioned so that the captured energy beam is incident on the front surface, and rotates with a direction perpendicular to the front surface as the rotation axis direction. Furthermore, the raw material supply mechanism 6 provides a raw material supply section that generates plasma by supplying plasma raw material to the incident region on the surface where the energy beam is incident. The vacuum chamber 3 also functions as a chamber for accommodating the plate member.

[0085] [Radiation R generation process] [Raw material supply] The rotor 22 rotates around a rotation axis 39 with a portion of the lower side of the rotor 22 immersed in the plasma raw material 23 stored in a container 24 . The plasma raw material 23 is pulled up from the raw material storage portion of the container 24 so that it fits onto the surface 22a of the rotor 22 due to its wettability with the surface 22a of the rotor 22. Then, in the state where it is coated on the surface 22a of the rotor 22, it is transported to an incident region 25 where the energy beam EB is incident. As shown in FIG. 2, the rotation direction of the rotor 22 is such that the plasma raw material supplied to the surface 22a of the rotor 22 is pulled up from the raw material storage portion of the container, passes through the skimmer 40, and reaches the plasma generation region 21 (incident region 25).

[0086] [Plasma generation] Plasma raw material 23, which has passed through skimmer 40 and has its thickness adjusted to a predetermined thickness on rotor 22, reaches incident region 25 on rotor 22. An energy beam EB is emitted from beam source 13 along incident axis IA toward incident region 25. Energy beam EB passes through incident hole 9, incident window 19, rotary window 27, and incident-side aperture 26, and enters incident region 25 to which plasma raw material 23 has been supplied. When the energy beam EB is incident on the incident region 25, the plasma raw material 23 present in the incident region 25 is heated and excited, generating high-temperature plasma P. Radiation R of a predetermined wavelength is emitted from the high-temperature plasma P generated in the plasma generation region 21.

[0087] [Extraction of radiation R] The radiation R emitted from the high-temperature plasma P travels in various directions. Of these, the radiation R that enters the extraction chamber 5 passes through the extraction chamber 5 and is guided to an application device (application chamber 30) such as a mask inspection device. In other words, of the radiation R emitted from the high-temperature plasma P, the component that enters the extraction chamber 5 is extracted to the outside along the extraction axis EA.

[0088] [Measures against scattered plasma raw materials 23 and debris] In the step of supplying plasma raw material 23, when rotor 22 rotates, centrifugal force may cause plasma raw material 23 adhering to surface 22a of rotor 22 to scatter. Furthermore, in the process of generating plasma P, when the energy beam EB is irradiated onto the plasma raw material 23 applied to the rotor 22, part of the plasma raw material 23 is vaporized. At that time, part of the plasma raw material 23 (particles of the plasma raw material 23) is released as debris. For example, ions, neutral particles, electrons, etc. are emitted as debris along with the radiation R. Furthermore, the generation of plasma P may cause the rotor 22 to be sputtered, and material particles of the rotor 22 may be emitted as debris.

[0089] The light source device 1 according to this embodiment employs a technique that can suppress the effects of scattered plasma raw material 23 and debris generated by the radiation of the energy beam EB. This point will be explained below.

[0090] If the scattered plasma raw material 23 or debris enters the injection chamber 4 through the injection-side aperture 26, the plasma raw material 23 or debris may adhere to the injection window 19. In this case, if the energy beam EB is, for example, a laser beam, the intensity of the laser beam will be reduced by the plasma raw material 23 or debris adhering to the injection window 19. As a result, there is a risk that the intensity of the radiation R extracted from the plasma P will be reduced.

[0091] In the light source device 1 according to this embodiment, the vacuum chamber 3 is maintained at an atmosphere that is reduced in pressure compared to the entrance chamber 4. Therefore, the gas supplied from the gas injection path 28 into the entrance chamber 4 flows from the entrance-side aperture 26 toward the vacuum chamber 3. This makes it possible to prevent scattered plasma raw material 23 and debris from entering the entrance chamber 4 through the entrance-side aperture 26. Furthermore, inner protrusion 17 that constitutes injection chamber 4 is cone-shaped, and an injection-side aperture 26 is provided at its tip. Therefore, by supplying gas into injection chamber 4 from gas injection path 28, it is possible to maintain the internal pressure of injection chamber 4 at a pressure that is sufficiently higher than the internal pressure of vacuum chamber 3. This makes it more difficult for plasma raw material 23 and debris to enter injection chamber 4 through injection-side aperture 26. Furthermore, the formation of the entrance side aperture 26 itself is advantageous in suppressing the entrance of the plasma raw material 23 and debris into the entrance chamber 4 .

[0092] A rotary window 27 is also placed inside the injection chamber 4. This makes it possible to sufficiently prevent plasma raw material 23 and debris from adhering to the injection window 19. Furthermore, because the intrusion of plasma raw material 23 and debris into the injection chamber 4 is prevented, the life of the rotary window 27 can be extended, and the frequency with which the rotary window 27 needs to be replaced can be reduced.

[0093] The vacuum chamber 3 is maintained at an atmosphere that is reduced in pressure compared to the exit chamber 5. Therefore, the gas supplied from the gas injection path 32 into the exit chamber 5 flows from the exit-side aperture 34 toward the vacuum chamber 3. This makes it possible to prevent scattered plasma raw material 23 and debris from entering the exit chamber 5 through the exit-side aperture 34. Furthermore, the outer protrusion 15 and inner protrusion 16 that make up the extraction chamber 5 are cone-shaped, and an extraction-side aperture 34 is provided at the tip of the inner side. Therefore, by supplying gas into the extraction chamber 5 from the gas injection path 32, it is possible to maintain the internal pressure of the extraction chamber 5 at a pressure that is sufficiently higher than the internal pressure of the vacuum chamber 3. This makes it more difficult for the plasma raw material 23 and debris to enter the extraction chamber 5 through the extraction-side aperture 34. Furthermore, the formation of the exit aperture 34 itself is advantageous in suppressing the entrance of the plasma raw material 23 and debris into the exit chamber 5 . Furthermore, by forming the inward protrusion 16, it is possible to position the exit aperture 34 close to the generated plasma P. This makes it possible to reduce the opening area of ​​the exit aperture 34 for taking in the necessary radiation R. As a result, this is advantageous in suppressing the intrusion of the plasma raw material 23 and debris into the exit chamber 5.

[0094] For example, if the radiation R is EUV light and the plasma raw material is Sn, most of the scattered plasma raw material 23 and debris will be Sn. Since Sn has a melting point of approximately 232°C, it may solidify and deposit on the outer or inner surface of the inner protrusion 16. As the deposition progresses, the exit aperture 34 may become clogged with the deposited Sn. To prevent such a problem, the inner protrusion 16 may be heated by a heating means or temperature control means (not shown) to maintain the temperature at or above the melting point of the plasma raw material 23. This makes it possible to prevent the exit aperture 34 from being blocked.

[0095] 1, an external voltage source 51 may be provided to apply a positive or negative voltage to the inner protrusion 16. Applying a voltage to the inner protrusion 16 generates an electric field that can repel ionic debris from the inner protrusion 16 or divert the debris from its path into the extraction chamber 5. In this case, the inner protrusion 16 is electrically insulated from other components such as the vacuum chamber 3 by an insulator (not shown) made of a ceramic material or the like. The operation of the external voltage source 51 is controlled by the control unit 7. In this embodiment, an external voltage source 51 serves as a voltage application unit that applies a voltage to the emission-side protrusion.

[0096] A filter film 35 is provided at the front end of the extraction chamber 5. The filter film 35 can block scattered plasma raw material 23 and debris from entering the application chamber 30. If the plasma raw material 23 and debris accumulate on the surface of the filter film 35 (the surface on the side of the emission chamber 5), the transmittance of the radiation R will gradually decrease. The filter film 35 may be configured to be movable, such as rotatable, so that when a certain amount of debris accumulates on the filter film 35, the area free of debris is exposed to the extraction chamber 5. Alternatively, a replaceable configuration may be adopted. By adopting such a configuration, it is possible to suppress the effects of scattered plasma raw material 23 and debris.

[0097] In addition, a shielding member 36 is disposed in the emission chamber 5. The shielding member 36 can prevent debris traveling along the emission axis EA or its vicinity from reaching the filter film 35. In particular, some of the debris moves at relatively high speeds, and if it directly collides with the filter membrane 35, it may damage the filter membrane 35. In this embodiment, the shielding member 36 can prevent debris and the like from colliding with the filter membrane 35, and can prevent damage to the filter membrane 35. As a result, the life of the filter membrane 35 can be extended.

[0098] FIG. 3 is a schematic diagram showing another example of the configuration of a container applicable to the light source device 1. In FIG. In the example shown in FIG. 3, the container 24 is configured as a cover-like structure, and is capable of surrounding almost the entire rotating body 22. An opening 52 is formed in the container 24 at a position corresponding to the incident region 25 set on the surface 22a of the rotor 22. An energy beam EB is incident on the incident region 25 through the opening 52, generating plasma P. Radiation R is extracted from the plasma P through the opening 52 and emitted via the extraction chamber 5. By configuring the container 24 as a cover-like structure, the plasma raw material 23 scattered from the rotor 22 adheres to the inner wall of the container 24, except for the opening 52 of the container 24. The plasma raw material 23 adhering to the inner wall then moves to the raw material storage section at the bottom of the container 24. Therefore, the plasma raw material 23 hardly scatters in the space outside the container 24 and inside the vacuum chamber 3. As a result, it is possible to sufficiently prevent the scattered plasma raw material 23 from adhering to the inner wall of the vacuum chamber 3.

[0099] [Arrangement of Rotating Body 22] In the light source device 1, a new technology is also adopted for the arrangement of the rotor 22 as a measure against debris. 4 to 6 are schematic diagrams for explaining the arrangement of the rotor 22. FIG.

[0100] In the light source device 1, the arrangement configuration of the rotating body 22 is appropriately determined based on the relative positions of the incident axis IA of the energy beam EB incident on the incident region 25 of the rotating body 22, the exit axis EA of the radiation R extracted from the plasma P, and the normal axis NA in the incident region 25 of the surface 22a of the rotating body 22. The normal axis NA is an axis extending along the normal direction from the point of incidence of the energy beam EB on the incident region 25 .

[0101] As shown in FIG. 4, in the light source device 1, the rotating body 22 is arranged so that the incident axis IA, the exit axis EA, and the normal axis NA are all different from one another. In addition, the rotor 22 is positioned so that the normal axis NA at the incident region 25 of the surface 22a is offset from the inter-axial region 54 formed between the incident axis IA of the energy beam EB incident on the incident region 25 and the exit axis EA of the radiation R extracted from the plasma P. That is, the rotor 22 is arranged so that the normal axis NA does not pass through an inter-axial region 54 between the incident axis IA and the exit axis EA.

[0102] When plasma raw material 23 is supplied onto a flat surface and irradiated with energy beam EB, the debris released when plasma raw material 23 is vaporized is released most largely along the normal direction of the area where energy beam EB is incident. In other words, a large amount of debris is released along the normal axis NA extending along the normal direction. In the light source device 1 according to this embodiment, the normal axis NA is positioned differently from the entrance axis IA and the exit axis EA, which allows the entrance-side aperture 26 and the exit-side aperture 34 to be located away from the direction in which a large amount of debris is emitted as the plasma P is generated. As a result, it is possible to prevent debris from entering the entrance chamber 4 and the exit chamber 5.

[0103] Furthermore, the rotor 22 is disposed so that the normal axis NA is offset from the opening of the entrance-side aperture 26. This makes it possible to further suppress the intrusion of debris into the entrance chamber 4. Similarly, the rotor 22 is disposed so that the normal axis NA is offset from the opening of the exit aperture 34. This makes it possible to further suppress the intrusion of debris into the exit chamber 5. 4, in this embodiment, the normal axis NA is configured to deviate from the opening of the entrance-side aperture 26 and the opening of the exit-side aperture 34. Therefore, the intrusion of debris into the entrance chamber 4 and the exit chamber 5 is sufficiently suppressed.

[0104] 1 and 4, in this embodiment, a gas nozzle 55 is installed to extend in the left-right direction on the rear side of incidence chamber 4. Gas nozzle 55 is installed on the right side surface of chamber body 14 via a seal member or the like. The gas nozzle 55 is connected to a gas supply device (not shown) and supplies gas into the chamber body 14 .

[0105] In the example shown in Figures 1 and 4, when viewing the light source device 1 from above, the normal axis NA of the incident region 25 of the rotating body 22 is located at a position off to the left of the inter-axial region 54 between the incident axis IA and the exit axis EA. Gas is then sprayed from gas nozzle 55 from the right side of inter-axial region 54 toward the left side along the left-right direction. That is, the gas is sprayed in a direction that intersects with incident axis IA, exit axis EA, and normal axis NA, and ultimately reaches normal axis NA. This makes it possible to move the debris that is emitted most in large quantities along the normal axis NA in the incident area 25 in a direction away from the incident axis IA and the exit axis EA. As a result, it is possible to further suppress the intrusion of debris into the injection chamber 4 and the extraction chamber 5. Note that by increasing the gas flow rate, it is possible to enhance the effect of suppressing the intrusion of debris into the injection chamber 4 and the extraction chamber 5.

[0106] In this way, the gas is blown in a direction from the inter-axial region 54 toward the normal axis NA so that the normal axis NA is located downstream of the inter-axial region 54. This makes it possible to sufficiently prevent debris emitted in conjunction with the generation of plasma P from entering the entrance chamber 4 and the exit chamber 5. The type of gas used may be a rare gas such as argon or helium, etc. For example, the same type of gas as that supplied to the inside of the entrance chamber 4 and the exit chamber 5 may be used.

[0107] FIG. 5 is a schematic diagram for explaining the inter-shaft region 54 in detail. In the light source device 1, the incident axis IA of the energy beam EB and the exit axis EA of the radiation R are set in a three-dimensional space. As shown in FIG. 5A, first, consider a plane 57 that includes the incident axis IA and the exit axis EA. In the example shown in FIG. 5, plane 57 is a plane that is not parallel to any of the XY plane, the YZ plane, and the ZX plane. Specifically, the plane is inclined downward relative to the XY plane on the near side of the page. Of course, the plane is not limited to this. 5B , a two-dimensional region 58 between the incident axis IA and the exit axis EA on a plane 57 including the incident axis IA and the exit axis EA is moved along the normal direction of the plane 57. A three-dimensional region formed by the trajectory when the two-dimensional region 58 is moved upward and downward along the normal direction to the plane 57 can be defined as an inter-axis region 54. The rotor 22 may be disposed so that the normal axis NA at the incident area 25 (incident point) is out of the inter-axis area . Furthermore, when blowing the gas, the gas should be blown in a direction from the inter-axial region 54 toward the normal axis NA so that the normal axis NA is located downstream of the inter-axial region 54. As long as this condition is satisfied, the direction in which the gas is blown may be set arbitrarily, and for example, the gas may be blown from an oblique direction that intersects with the two-dimensional region 58.

[0108] In the example shown in FIG. 5B, the triangular area connecting the position of the entrance-side aperture 26 on the entrance axis IA, the position of the exit-side aperture 34 on the exit axis EA, and the entrance area 25 is defined as the two-dimensional area 58. Of course, the present invention is not limited to this, and the two-dimensional region 58 may be defined using other points on the incident axis IA and other points on the exit axis EA. Furthermore, two-dimensional region 58 may be defined so as to include all of the extension directions of the incident axis IA and the exit axis EA without defining points on the incident axis IA and the exit axis EA. In this case, two-dimensional region 58 does not have a triangular shape, but becomes a two-dimensional region that expands in the extension directions of the incident axis IA and the exit axis EA.

[0109] Furthermore, by increasing the angle between the incident axis IA of the energy beam EB and the normal axis NA, it becomes possible to prevent the debris, which is most likely to be emitted along the normal axis NA, from entering the injection chamber 4. Similarly, by increasing the angle between the emission axis EA of the radiation R and the normal axis NA, it is possible to prevent the debris, which is emitted in greatest quantity along the normal axis NA, from entering the injection chamber 4. The angle between the incident axis IA and the normal axis NA can be defined, for example, by the intersection angle on a plane including the incident axis IA and the normal axis NA. Similarly, the angle between the exit axis EA and the normal axis NA can be defined, for example, by the intersection angle on a plane including the exit axis EA and the normal axis NA.

[0110] For example, the light source device 1 is configured so that at least one of the angle between the incident axis IA and the normal axis NA or the angle between the exit axis EA and the normal axis NA is within the range of 30 to 60 degrees, thereby making it possible to suppress the influence of debris. Furthermore, the light source device 1 may be configured so that the angle between the incident axis IA and the normal axis NA and the angle between the exit axis EA and the normal axis NA are each within the range of 30 to 60 degrees. In this case, it is still possible to suppress the effect of debris.

[0111] As shown in FIG. 6, the positions of the entrance chamber 4 and the exit chamber 5 can be interchanged. In the configuration example shown in Fig. 4, the entrance axis IA is located farther from the normal axis NA than the exit axis EA. Therefore, in the configuration example shown in Fig. 4, it is possible to suppress the intrusion of debris into the entrance chamber 4 to a greater extent than the intrusion of debris into the exit chamber 5. In the configuration example shown in Fig. 6, the exit axis EA is located farther from the normal axis NA than the entrance axis IA, so the configuration example shown in Fig. 6 can more effectively prevent debris from entering the exit chamber 5 than it can prevent debris from entering the entrance chamber 4. In this way, it is possible to design the chamber in which it is desired to more effectively suppress the intrusion of debris, either the entrance chamber 4 or the exit chamber 5, so that it is farther from the normal axis NA. This makes it possible to sufficiently suppress the effects of debris.

[0112] As described above, in the light source device 1 according to this embodiment, the plasma raw material 23 is supplied to the surface 22a of the rotatable rotor 22, and the surface 22a is irradiated with the energy beam EB. This generates the plasma P, and the radiation R is emitted. The rotor 22 is arranged so that the normal axis NA in the incident region 25 where the energy beam EB is incident is deviated from the interaxial region 54 between the incident axis IA of the energy beam EB and the exit axis EA of the radiation R. This makes it possible to suppress the influence of debris that accompanies the generation of plasma P.

[0113] In the light source device 1, one of the two main surfaces of the plate-shaped rotor 22 is set as the surface 22a, and an incident area 25 onto which the energy beam EB is incident is set. This makes it easier to design the device and simplifies the device compared to, for example, a case where the energy beam EB is incident on the end face (side face) of the rotor 22. It also makes it possible to improve the degree of freedom in the layout design of each component. Furthermore, if the plasma raw material (radiation raw material) supplied to the rotor 22 is liquid, depending on the rotation speed of the rotor 22, the plasma raw material may detach from the end face of the rotor 22 and scatter as droplets. That is, because the state of the plasma raw material supplied to the end face (side face) of the rotor 22 is unstable, the shape of the plasma raw material (thickness of the plasma raw material) in the region on the end face irradiated with the energy beam EB is likely to be unstable, and as a result, the intensity of the radiation emitted from the plasma may be unstable. Therefore, it is preferable to irradiate the energy beam EB onto the surface 22a of the rotor 22 rather than onto the end face (side face).

[0114] <Other embodiments> The present invention is not limited to the above-described embodiment, and various other embodiments can be realized.

[0115] The configurations of the light source device, the rotating body, the various chambers, the raw material supply mechanism, and the like 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 configuration for implementing the present technology may be adopted.

[0116] In this disclosure, to facilitate understanding of the explanation, words such as "approximately," "almost," and "roughly" are used as appropriate. However, there is no clear difference between using and not using words such as "approximately," "almost," and "roughly." 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," "cylindrical," "cylindrical," "ring-shaped," and "annular," 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 cylindrical," "substantially cylindrical," "substantially ring-shaped," "substantially annular," and the like. For example, this also includes states that fall within a specified range (for example, a range of ±10%) based on criteria such as "perfectly centered," "perfectly central," "perfectly uniform," "perfectly equal," "perfectly the same," "perfectly perpendicular," "perfectly parallel," "perfectly symmetrical," "perfectly extended," "perfectly axial," "perfectly cylindrical," "perfectly cylindrical," "perfectly ring-shaped," and "perfectly annular." Therefore, even if the words "roughly," "almost," "approximately," etc. are not added, it may include concepts that can be expressed by adding "roughly," "almost," "approximately," etc. Conversely, a state expressed by adding "roughly," "almost," "approximately," etc. does not necessarily exclude a complete state.

[0117] In this disclosure, expressions using "than", such as "greater than A" and "smaller than A", are expressions that comprehensively include both concepts that include equivalent to A and concepts that do not include 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 may be appropriately adopted from the concepts included in "greater than A" and "smaller than A" so as to achieve the effects described above.

[0118] 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 distinction between the embodiments. Furthermore, the various effects described above are merely examples and are not limiting, and other effects may also be achieved. [Explanation of symbols]

[0119] EA: Radiation emission axis EB...energy beam IA...Incident axis of energy beam NA: Normal axis in the incident area R...Radiation 1...Light source device 3...Vacuum chamber 4...Energy beam injection chamber 5...Radiation emission chamber 6...Raw material supply mechanism 15...Outer protrusion 16, 17...Inner protrusion 21...Plasma generation region 22...Rotating body 22a...Surface of the rotating body 23...Plasma raw material 24...Container 25...Incidence area 26...Inlet aperture 34...Output aperture 39...Rotation axis 40...Skimmer 41...Plasma raw material circulation device 54…Area between shafts 55...Gas nozzle

Claims

1. a beam capture unit that captures the energy beam; a plate member having a front surface and a back surface, disposed at a position where the captured energy beam is incident on the front surface, and rotating about a rotation axis in a direction perpendicular to the front surface; a raw material supply unit that generates plasma by supplying a plasma raw material to an incident region on the surface where the energy beam is incident; a radiation extraction unit that extracts and emits radiation from the generated plasma; a chamber that accommodates the plate member; Voltage application section and Equipped with the plate member is arranged such that a normal axis of the incident region of the surface deviates from an inter-axial region defined between an incident axis of the energy beam incident on the incident region and an exit axis of the radiation extracted from the plasma; the radiation extraction unit includes an exit chamber connected to the chamber, an exit-side aperture that allows the radiation to enter the exit chamber from the chamber, and an exit-side protrusion that protrudes toward the incident region and has the exit-side aperture provided at a tip of the protruding side, The voltage application unit applies a voltage to the emission-side protrusion. Light source device.

2. The light source device according to claim 1 , The plate member is configured so that the normal axis is offset from the opening of the exit-side aperture. Light source device.

3. 3. The light source device according to claim 1 or 2, further comprising: a chamber for accommodating the plate member; the beam intake unit has an incident chamber connected to the chamber and an incident-side aperture through which the energy beam is incident from the incident chamber into the chamber; The plate member is disposed so that the normal axis is offset from the opening of the entrance-side aperture. Light source device.

4. 3. The light source device according to claim 1 or 2, further comprising: a gas supply unit that blows gas in a direction from the inter-axis region toward the normal axis so that the normal axis is located downstream of the inter-axis region; Light source device.

5. The light source device according to claim 3, A gas for increasing the pressure inside the incident chamber to a value higher than the pressure inside the chamber is supplied into the incident chamber so that the gas flows from the incident-side aperture toward the chamber. Light source device.

6. 3. The light source device according to claim 1, A gas for increasing the pressure inside the emission chamber to be higher than the pressure inside the chamber is supplied into the emission chamber so that the gas flows from the emission side aperture toward the chamber. Light source device.

7. 3. The light source device according to claim 1, The inter-axial region includes a three-dimensional region formed by a locus when a two-dimensional region between the incident axis and the emission axis on a plane including the incident axis and the emission axis is moved along a normal direction of the plane. Light source device.

8. 3. The light source device according to claim 1, At least one of the angle between the incident axis and the normal axis or the angle between the exit axis and the normal axis is configured to be within a range of 30 degrees to 60 degrees. Light source device.

9. The light source device according to claim 8, The angle between the incident axis and the normal axis and the angle between the exit axis and the normal axis are each configured to be within a range of 30 degrees to 60 degrees. Light source device.

10. The light source device according to claim 3, The beam capture unit has an incident-side protrusion that protrudes toward the incident area and has the incident-side aperture provided at a tip of the protruding side. Light source device.

11. The light source device according to claim 10, The incident-side protrusion has a cone shape whose cross-sectional area decreases toward the protrusion side. Light source device.

12. 3. The light source device according to claim 1, The emission-side protrusion has a cone shape whose cross-sectional area decreases toward the protrusion side. Light source device.

13. 3. The light source device according to claim 1, The radiation is X-rays or extreme ultraviolet light. Light source device.

14. 3. The light source device according to claim 1 or 2, further comprising: A thickness adjusting mechanism is provided to adjust the thickness of the plasma raw material supplied to the surface. Light source device.

15. a beam capture unit that captures the energy beam; a plate member having a front surface and a back surface, disposed at a position where the captured energy beam is incident on the front surface, and rotating about a rotation axis in a direction perpendicular to the front surface; a raw material supply unit that generates plasma by supplying a plasma raw material to an incident region on the surface where the energy beam is incident; a radiation extraction unit that extracts and emits radiation from the generated plasma; Gas supply unit and Equipped with the plate member is arranged such that a normal axis of the incident region of the surface deviates from an inter-axial region defined between an incident axis of the energy beam incident on the incident region and an exit axis of the radiation extracted from the plasma; The gas supply unit blows gas in a direction from the inter-axis region toward the normal axis so that the normal axis is located downstream of the inter-axis region. Light source device.

16. 16. The light source device according to claim 15, The gas supply unit blows the gas toward the inter-axis region and the normal axis from a position away from the inter-axis region on the opposite side from the normal axis. Light source device.

17. 17. The light source device according to claim 15 or 16, The inter-axial region includes a three-dimensional region formed by a locus when a two-dimensional region between the incident axis and the emission axis on a plane including the incident axis and the emission axis is moved along a normal direction of the plane. Light source device.

18. 17. The light source device according to claim 15 or 16, At least one of the angle between the incident axis and the normal axis or the angle between the exit axis and the normal axis is configured to be within a range of 30 degrees to 60 degrees. Light source device.

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