Debris reduction device and light source device equipped therewith

Abstract

To provide a debris reduction device which can be improved in probability of capturing of debris, and a light source device therewith.SOLUTION: A debris reduction device according to one embodiment of the present technique includes a fixed foil trap. The fixed foil trap has a casing portion, a plurality of foils, an inflow port, and a pressure increase mechanism. The casing portion has an incident port into which light emitted from a light source enters, an ejection port through which light entered from the entrance progresses, and an internal space through which the light progresses. A plurality of foils are fixed to a region of the interior space through which the light progresses. The inflow port is configured to communicate with the internal space of the casing portion, and a transparent gas that is transparent to light flows into the inflow port. A pressure increase mechanism includes at least one of: an incidence-side member placed at the incident port in such a manner that an opening area of the incident port is reduced without blocking the progress of the light; and an ejection side member that is arranged at the entrance port in such a manner that the opening area of the ejection port is reduced without blocking the progress of the light, and consequently the pressure increase mechanism increases the pressure of the internal space.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present technology relates to a debris reduction device for capturing debris and a light source device equipped with the same.

Background Art

[0002] In recent years, with the miniaturization and high integration of semiconductor integrated circuits, the short wavelength of the light source for exposure has been progressing. As a next-generation light source for semiconductor exposure, in particular, the development of an extreme ultraviolet light source device (hereinafter also referred to as "EUV light source device") that emits extreme ultraviolet light (hereinafter also referred to as "EUV (Extreme Ultra Violet) light") with a wavelength of 13.5 nm has been advanced.

[0003] In an EUV light source device, several methods for generating EUV light (EUV emission) are known. One of these methods is to generate plasma by heating and exciting an extreme ultraviolet radiation species (hereinafter also referred to as EUV radiation species), and extract EUV light from the plasma.

[0004] An EUV light source device adopting such a method is classified into an LPP (Laser Produced Plasma) method and a DPP (Discharge Produced Plasma) method according to the plasma generation method.

[0005] A DPP-type EUV light source device applies a high voltage between electrodes to which a discharge gas containing an EUV radiation species (gas-phase plasma raw material) is supplied, generates high-density plasma by discharge, and uses the extreme ultraviolet light radiated therefrom.

[0006] Patent Document 1 discloses a DPP (Laser Assisted Discharge Produced Plasma) type light source device. In this light source device, a liquid plasma material containing EUV emitting species (for example, tin (Sn) or lithium (Li)) is supplied to the electrode surface that generates the discharge, and an energy beam such as a laser beam is irradiated onto the material to vaporize it, after which plasma is generated by discharge. Such a method is sometimes referred to as the LDP (Laser Assisted Discharge Produced Plasma) method.

[0007] Furthermore, LPP-type EUV light sources irradiate a target material with laser light, exciting the target material and generating plasma.

[0008] As mentioned above, EUV light sources are used as light sources for semiconductor exposure equipment (lithography equipment) in semiconductor device manufacturing. Alternatively, EUV light sources are used as light sources for inspection equipment for masks used in lithography. In other words, EUV light sources are used as light sources for other optical systems (utilizing equipment) that utilize EUV light.

[0009] In EUV light source devices, debris is emitted from the plasma. This debris includes particles of the plasma raw material (tin particles if the plasma raw material is tin). Furthermore, when plasma is generated using the DPP or LDP method, the debris includes material particles of the discharge electrodes that are sputtered during plasma generation.

[0010] When debris reaches the user's equipment, it can damage or contaminate the reflective coatings of optical elements within the equipment, degrading its performance. Therefore, a debris mitigation device (also known as a DMT (Debris Mitigation Tool)) has been proposed to capture dispersed debris and prevent it from entering the user's equipment.

[0011] Foil traps are commonly used as debris reduction devices. The light source device described in Patent Document 1 employs a debris reduction device that uses a foil trap. This technology includes a rotating foil trap and a fixed foil trap that does not rotate.

[0012] A rotary foil trap consists of multiple foils (thin films or thin flat plates) arranged radially around a centrally located axis of rotation. By rotating these multiple foils around the axis of rotation, it captures debris flying from the plasma. Here, the axis of rotation is, for example, an axis that penetrates approximately the center of the plasma.

[0013] A fixed foil trap captures high-speed moving debris (especially ions, neutral atoms, and electrons of plasma raw materials that move at high speed) that could not be captured by a rotating foil trap. The fixed foil trap has a central axis coaxial with the rotation axis of the rotating foil trap and comprises multiple foils (thin films or thin flat plates) arranged radially from this central axis.

[0014] The multiple wheels of a fixed wheel trap divide the space in which they are placed into smaller sections, thereby lowering the conductance in those sections and increasing the pressure. In other words, high-speed debris that could not be captured by a rotating wheel trap will have a lower velocity because the probability of collision increases in the pressure-enhanced region of the fixed wheel trap, making it easier to capture by the wheels and support structures of the fixed wheel trap.

[0015] Furthermore, the EUV light emitted from the EUV light source is appropriately shaped depending on the device being used. For example, when the EUV light source is used as the light source for a mask inspection device, an aperture member (corresponding to a heat shield, which will be described later) having an opening of a predetermined shape is placed between the high-temperature plasma and the device being used.

[0016] Patent Document 2 discloses a debris trap having an aperture member. In this debris trap, a fixed foil trap is positioned on the main beam of the EUV light extracted from the aperture member and has a shape corresponding to the region through which the EUV light passes. [Prior art documents] [Patent Documents]

[0017] [Patent Document 1] Patent No. 6075096 [Patent Document 2] Patent No. 6759732 [Overview of the project] [Problems that the invention aims to solve]

[0018] As mentioned above, fixed-wheel traps capture debris moving at high speed in areas where the pressure between the wheels increases. The probability of capturing this debris depends on the pressure between the wheels. Therefore, the object of the present invention is to provide a debris reduction device that can improve the probability of capturing debris, and a light source device equipped therewith.

[0019] In light of the above circumstances, the objective of this technology is to provide a debris reduction device that can improve the probability of capturing debris, and a light source device equipped therewith. [Means for solving the problem]

[0020] To achieve the above objective, a debris reduction device according to one embodiment of this technology is equipped with a fixed wheel trap. The aforementioned fixed-type foil trap comprises a housing, a plurality of foils, an inlet hole, and a pressure increasing mechanism. The housing portion has an inlet into which light emitted from the light source enters, an outlet into which the light that entered from the inlet exits, and an internal space through which the light travels. The plurality of foils are fixed in a region through which the light in the internal space travels. The inflow hole is configured to communicate with the internal space in the housing portion, and a transparent gas that is transparent to the light flows in. The pressure increasing mechanism includes at least one of an incident side member disposed at the incident port so that the opening area of the incident port becomes smaller without blocking the progress of the light, or an emission side member disposed at the emission port so that the opening area of the emission port becomes smaller without blocking the progress of the light, and increases the pressure in the internal space.

[0021] In this debris reduction device, a plurality of foils are arranged in the internal space of the housing portion. Also, a transparent gas flows into the internal space. Further, a pressure increasing mechanism for increasing the pressure in the internal space is arranged. Thereby, it becomes possible to improve the capture probability of debris.

[0022] At least one of the incident side member or the emission side member may be a lid member having a plate shape and an opening through which the light passes.

[0023] At least one of the incident side member or the emission side member may be a block member having a block shape, having an opening through which the light passes, and arranged so as to fill the internal space.

[0024] The fixed foil trap may have an electromagnetic field generation unit that generates an electric field or a magnetic field that moves charged particles excited by the light among the particles contained in the transparent gas in a direction away from the plurality of foils.

[0025] The internal space may include a buffer space in which the plurality of foils do not exist. In this case, the inflow hole may be configured to communicate with the buffer space.

[0026] The fixed foil trap may be disposed between each of the light source and a utilization device that uses the light emitted from the light source, and between the light source and a monitoring device that monitors the state of the light emitted from the light source.

[0027] The light source may be plasma.

[0028] The debris reduction device may further include a cover member having an inlet into which light emitted from the light source enters, an outlet into which the light that entered from the inlet exits, and an internal space through which the light travels, and a plurality of rotating wheels rotatably mounted with respect to the region of the internal space through which the light travels.

[0029] The rotary foil trap may include at least one of an inlet-side member positioned at the inlet so as to reduce the opening area of ​​the inlet without obstructing the propagation of light, or an outlet-side member positioned at the outlet so as to reduce the opening area of ​​the outlet without obstructing the propagation of light, and may have a pressure increasing mechanism to increase the pressure in the internal space.

[0030] The fixed wheel trap and the rotating wheel trap may be positioned so that the outlet of the rotating wheel trap and the inlet of the fixed wheel trap face each other. In this case, the debris reduction device may further include a connecting member that connects the outlet of the rotating wheel trap and the inlet of the fixed wheel trap.

[0031] The debris reduction device may further include an aperture member positioned between the light source and the rotating wheel trap, having an opening for extracting a portion of the light emitted from the light source.

[0032] A light source device according to one embodiment of this technology comprises a debris reduction device having a plasma generation chamber that excites a light-emitting raw material to generate plasma, a light extraction unit that extracts light emitted from the plasma, and the fixed foil trap.

[0033] The debris reduction device may further include the rotary wheel trap. [Effects of the Invention]

[0034] According to the present invention, it is possible to improve the probability of capturing debris. However, the effects described herein are not necessarily limited and may be any of the effects described herein. [Brief explanation of the drawing]

[0035] [Figure 1] This is a schematic diagram showing an example of the configuration of a light source device according to one embodiment of this technology. [Figure 2] This is a schematic diagram showing an example of the configuration of a light source device according to one embodiment of this technology. [Figure 3] This is a schematic diagram showing an example of the configuration of a rotary foil trap. [Figure 4] This is a schematic diagram showing an example of the configuration of a fixed foil trap in the reference example. [Figure 5] This is a schematic diagram showing an example of the configuration of a fixed foil trap in the reference example. [Figure 6] This is a schematic diagram showing an example of a fixed foil trap configuration. [Figure 7] This is a schematic diagram showing an example of a fixed foil trap configuration. [Figure 8] This is a schematic diagram showing an example of a fixed foil trap configuration. [Figure 9] This is a schematic diagram showing an example of the configuration of a pressure regulating plate. [Figure 10] This is a schematic diagram showing an example of the configuration of a pressure regulating plate. [Figure 11] This is a schematic diagram showing the flow of argon gas in the comparative example of a debris reduction device. [Figure 12] This is a schematic diagram showing the flow of argon gas in the debris reduction device of this technology. [Figure 13] This is a schematic diagram showing an example of the configuration of a cavity limiting member. [Figure 14] This is a schematic diagram showing an example of the configuration of a cavity limiting member. [Figure 15] This is a schematic diagram showing an example of the configuration of a cavity limiting member. [Figure 16]This is a schematic diagram showing an example of the configuration of a spatial connection member. [Figure 17] This is a schematic diagram showing an example of the configuration of the front closure section. [Figure 18] This is a schematic diagram showing an example configuration in which a fixed foil trap is placed between a rotary foil trap and a monitoring device. [Figure 19] This is a schematic diagram showing an example of the configuration of a magnetic field application means. [Figure 20] This is a schematic diagram showing an example of the configuration of a magnetic field application means. [Figure 21] This is a schematic diagram showing an example of the configuration of a magnetic field application means. [Figure 22] This is a schematic diagram showing an example of a buffer space configuration. [Modes for carrying out the invention]

[0036] The embodiments of this technology will be described below with reference to the drawings.

[0037] [Light source device] Figures 1 and 2 are schematic diagrams showing examples of the configuration of a light source device. Figure 1 shows a schematic cross-section of the light source device 1 when it is cut horizontally at a predetermined height from the installation surface, viewed from the positive Z-direction. Hereafter, the X-direction will be described as the left-right direction (the positive X-axis is the right side, and the negative X-axis is the left side), the Y-direction as the depth direction (the positive Y-axis is the front side, and the negative Y-axis is the back side), and the Z-direction as the up-down direction (the positive Z-axis is the top side, and the negative Z-axis is the bottom side). Of course, the application of this technology is not limited to the orientation in which the light source device 1 is used.

[0038] Figure 2 is a schematic diagram showing the debris reduction device 3 portion of the light source device 1. Figure 2 illustrates a cross-section of the light source device 1 when cut along the XZ plane, as viewed from the front.

[0039] Light source device 1 is an LDP-type EUV light source device that emits extreme ultraviolet (EUV) light. Light source device 1 can be used, for example, as a light source device for a lithography apparatus in semiconductor device manufacturing, or as a light source device for an inspection apparatus for masks used in lithography. For example, when light source device 1 is used as a light source device for a mask inspection apparatus, a portion of the EUV light emitted from the plasma is extracted and guided to the mask inspection apparatus. The mask inspection apparatus then uses the EUV light emitted from light source device 1 as inspection light to perform blank inspection or pattern inspection of the mask.

[0040] The light source device 1 includes a light source unit 2, a debris reduction device 3, a debris containment unit 4, a debris guide unit 5, a control unit 12, a pulse power supply unit 13, a laser source 14, a focusing lens 15, a movable mirror 16, and a connection chamber 21.

[0041] [Light source section] The light source unit 2 includes a chamber 11, containers CA and CB, discharge electrodes EA and EB, and motors MA and MB. In Figure 1, the light source unit 2 is illustrated by a dashed rectangle.

[0042] Chamber 11 is a housing that accommodates various mechanisms of the light source unit 2. In this embodiment, Chamber 11 has a rectangular parallelepiped shape. Chamber 11 is made of a rigid body such as metal. Of course, the specific shape and material of Chamber 11 are not limited.

[0043] The inside of the chamber 11 is maintained in a reduced pressure atmosphere below a predetermined pressure by a vacuum pump (not shown). Feedthroughs FA and FB are positioned on the left side wall 11a of the chamber 11. Feedthroughs FA and FB are sealing members that allow the insertion of wires and the like into the chamber 11 while maintaining the reduced pressure atmosphere inside the chamber 11.

[0044] A transparent window 20 is positioned on the front side wall 11b of the chamber 11. A first window portion 17, which is a through-hole, is formed on the right side wall 11c of the chamber 11. In this embodiment, the transparent window 20 is made of a material that is transparent to the laser beam. The shape of the first window portion 17 and the specific configuration of the transparent window 20, such as the material and shape, are not limited.

[0045] Containers CA and CB are vessels for storing plasma raw materials. In this embodiment, containers CA and CB are made of conductive material. Plasma raw material SA is stored in container CA. Plasma raw material SB is stored in container CB. Plasma raw materials SA and SB are heated liquid phase raw materials. In this embodiment, tin (Sn) is used as plasma raw materials SA and SB. Alternatively, other raw materials capable of generating plasma, such as lithium (Li), may be used.

[0046] The discharge electrodes EA and EB have a disc shape. The discharge electrodes EA and EB are made of high-melting-point metals such as molybdenum (Mo), tungsten (W), or tantalum (Ta). The specific materials of the discharge electrodes EA and EB are not limited.

[0047] For example, discharge electrode EA is used as the cathode and discharge electrode EB is used as the anode. Discharge electrodes EA and EB are positioned spaced apart from each other. Furthermore, discharge electrodes EA and EB are positioned so that a portion of their respective peripheral edges are close together. The gap between the peripheral edges of discharge electrodes EA and EB at the closest point to each other becomes the discharge region D formed by discharge electrodes EA and EB.

[0048] Furthermore, the discharge electrode EA is positioned so that its lower part (the far side in Figure 1) is immersed in the plasma raw material SA stored in the container CA. Similarly, the discharge electrode EB is positioned so that its lower part is immersed in the plasma raw material SB.

[0049] Motor MA rotates the discharge electrode EA. Motor MA has a rotation axis JA. The base of motor MA is located outside the left side of chamber 11, and the rotation axis JA, connected to the base, extends from the outside to the inside of chamber 11. The inside end of the rotation axis JA of chamber 11 is connected to the center (center of the circular surface) of the discharge electrode EA.

[0050] The gap between the rotating shaft JA and the wall of the chamber 11 is sealed by a sealing member PA. For example, a mechanical seal is used as the sealing member PA. The sealing member PA maintains a reduced pressure atmosphere inside the chamber 11 while supporting the rotating shaft JA so that it can rotate freely.

[0051] Similarly, the motor MB has a rotating shaft JB, which is connected to the center of the discharge electrode EB. The gap between the rotating shaft JB and the wall of the chamber 11 is sealed by a sealing member PB.

[0052] Furthermore, the discharge electrodes EA and EB are positioned so that their respective axes (the direction of extension of the rotation axis) are not parallel. Specifically, as shown in Figure 1, discharge electrode EA is positioned with its front side (lower side in Figure 1) tilted to the right and its back side (upper side in Figure 1) tilted to the left. On the other hand, discharge electrode EB is positioned with its front side tilted to the left and its back side tilted to the right. The spacing between the rotation axes JA and JB in the depth direction (vertical direction and Z direction in Figure 1) is also narrower on the motor MA and MB side and wider on the discharge electrode EA and EB side. In addition, discharge electrode EB, motor MB and rotation axis JB are positioned slightly to the left of discharge electrode EA, motor MA and rotation axis JA.

[0053] The light source unit 2 corresponds to one embodiment of the plasma generation chamber according to this technology.

[0054] The control unit 12 controls the operation of each part of the light source device 1. For example, the control unit 12 controls the rotational drive of motors MA and MB, causing the discharge electrodes EA and EB to rotate at a predetermined speed. The control unit 12 also controls the operation of the pulse power supply unit 13 and the irradiation timing of the laser beam by the laser source 14.

[0055] For example, the control unit 12 is realized by a controller that has hardware necessary for the configuration of a computer, such as a processor (CPU, GPU, DSP, etc.), memory (ROM, RAM, etc.), and storage devices (HDD, etc.). Specifically, the control unit 12 is realized as a functional block when the controller's CPU executes a program related to this technology (for example, an application program).

[0056] The pulse power supply unit 13 generates a discharge in the discharge region D by supplying pulse power to the discharge electrodes EA and EB. Power supply lines QA and QB are connected to the pulse power supply unit 13. Power supply line QA is inserted into the chamber 11 via feedthrough FA and connected to container CA. Power supply line QB is inserted into the chamber 11 via feedthrough FB and connected to container CB.

[0057] The laser source 14 emits an energy beam that vaporizes the plasma raw materials SA and SB. The laser source 14 is located outside the chamber 11. For example, an Nd:YVO4 (Neodymium-doped Yttrium Orthovanadate) laser device is used as the laser source 14. In this case, the laser source 14 emits a laser beam LB in the infrared region with a wavelength of 1064 nm. Of course, the specific configuration of the laser source 14, such as the type of device and the wavelength of the laser beam LB that is irradiated, is not limited as long as it is possible to vaporize the plasma raw materials SA and SB.

[0058] The focusing lens 15 is positioned outside the chamber 11, on the optical path of the laser beam LB. The spot diameter of the laser beam LB is adjusted when the laser beam LB emitted by the laser source 14 enters the focusing lens 15.

[0059] The movable mirror 16 is positioned outside the chamber 11, on the optical path of the laser beam LB. The movable mirror 16 is positioned behind the focusing lens 15 on the optical path of the laser beam LB. That is, the laser beam LB that has passed through the focusing lens 15 is incident on the movable mirror 16.

[0060] The laser beam LB incident on the movable mirror 16 is reflected by the movable mirror 16 and passes through the transparent window 20 of the chamber 11. The laser beam LB then reaches the periphery of the discharge electrode EA near the discharge region D inside the chamber 11. The irradiation position of the laser beam LB on the discharge electrode EA can be adjusted by changing the orientation of the movable mirror 16.

[0061] The connection chamber 21 is a housing that accommodates mechanisms such as the debris reduction device 3. The connection chamber 21 has a rectangular parallelepiped shape, with one of its six faces being entirely a rectangular opening. The connection chamber 21 is connected to the chamber 11 such that the frame forming the opening abuts against the right side wall 11c of the chamber 11.

[0062] The connecting chamber 21 is constructed of a rigid body, such as metal. Of course, the specific shape and material of the connecting chamber 21 are not limited. The inside of the connecting chamber 21 is maintained in a reduced pressure atmosphere below a predetermined pressure.

[0063] A second window section 27 is formed in the upper part of the right side wall 21a of the connection chamber 21. The second window section 27 is a through-hole of a predetermined shape. An EUV light guide hole 28 is formed in the lower part of the right side wall 21a. A guide tube 29 is also formed extending downward to the right from the EUV light guide hole 28. Furthermore, an opening 37 for connecting the debris containment section 4 is formed in the lower side wall 21b.

[0064] [Operation of the light source] The light source unit 2 excites light-emitting raw materials (plasma raw materials SA and SB) to generate plasma P. The light source unit 2 also generates EUV light 6 using plasma P as the emission point. The following describes the specific details regarding the generation of plasma P and EUV light 6 by the light source unit 2.

[0065] First, the control unit 12 controls the operation of the pulse power supply unit 13, and the pulse power supply unit 13 supplies pulse power to the container CA. The pulse power is supplied via the power supply line QA.

[0066] Container CA is made of a conductive material. Plasma raw material SA is stored in container CA, and the lower part of the discharge electrode EA is immersed in the plasma raw material SA. Therefore, the pulse power supply unit 13, container CA, plasma raw material SA, and discharge electrode EA are all electrically connected to each other. That is, pulse power is supplied to the discharge electrode EA by the pulse power supply unit 13. Similarly, pulse power is supplied to the discharge electrode EB by the pulse power supply unit 13.

[0067] Furthermore, the control unit 12 controls the rotational drive of the motor MA, causing the discharge electrode EA to rotate. As the discharge electrode EA rotates, the plasma raw material SA is transported to the vicinity of the discharge region D while adhering to the surface of the discharge electrode EA. Similarly, the plasma raw material SB is transported to the vicinity of the discharge region D while adhering to the surface of the discharge electrode EB.

[0068] Furthermore, the control unit 12 controls the operation of the laser source 14, and the laser source 14 emits the laser beam LB. The laser beam LB is emitted to the right and reaches the movable mirror 16 via the focusing lens 15. The movable mirror 16 then reflects the laser beam LB toward the back (upper side in Figure 1), and it travels into the chamber 11 through the transparent window 20, reaching the periphery of the discharge electrode EA near the discharge region D.

[0069] The discharge electrode EB is positioned with its front side (lower side in Figure 1) tilted to the left. Furthermore, the discharge electrode EB is positioned slightly to the left of the discharge electrode EA. Therefore, the optical path of the laser beam LB is not obstructed by the discharge electrode EB. This arrangement of the discharge electrode EB facilitates the irradiation of the discharge electrode EA with the laser beam LB.

[0070] The plasma raw material SA, transported to the vicinity of the discharge region D by the discharge electrode EA, is vaporized by irradiation with the laser beam LB, becoming gaseous plasma raw material SA in the discharge region D. Similarly, the plasma raw material SB also becomes gaseous plasma raw material SB in the discharge region D.

[0071] Furthermore, when pulsed power is supplied to the discharge electrodes EA and EB, a discharge occurs between the discharge electrodes EA and EB (discharge region D). Due to the discharge, the gaseous plasma raw materials SA and SB present in the discharge region D are heated and excited by the current, generating plasma P.

[0072] Furthermore, EUV light 6 is emitted from the plasma P. A portion of the emitted EUV light 6 (light directed to the right) passes through the first window 17 and is emitted into the connection chamber 21. Figure 1 illustrates an example of the optical path of the EUV light 6 that has passed through the first window 17 with a dashed arrow. Plasma P corresponds to one embodiment of the light source according to this technology.

[0073] In this embodiment, the interiors of chamber 11 and connecting chamber 21 are maintained in a reduced pressure atmosphere below a predetermined pressure. This makes it possible to generate a discharge for heating and exciting the plasma raw materials SA and SB effectively. It also makes it possible to suppress the attenuation of EUV light 6.

[0074] From the plasma P, debris DB is emitted at high speed in various directions along with EUV light 6. Debris DB contains tin particles, which are the plasma raw materials SA and SB. Debris DB also contains material particles of the discharge electrodes EA and EB, which are sputtered as the plasma P is generated. Specifically, debris DB contains ions, neutral atoms, and electrons that move at high speed. These debris DB gain large kinetic energy through the contraction and expansion processes of the plasma P. A portion of the debris DB passes through the first window 17 and is emitted into the interior of the connection chamber 21.

[0075] [Debris reduction device] The debris reduction device 3 captures debris DB emitted from the plasma P. The debris reduction device 3 includes a rotating wheel trap 22, a heat shield 23, and a fixed wheel trap 24. All of these mechanisms are located inside the connection chamber 21.

[0076] The heat shield 23 is a plate-shaped component and is arranged parallel to the YZ plane. The heat shield 23 is also positioned between the plasma P and the rotating wheel trap 22. An aperture KA is formed at the top of the heat shield 23. An aperture KB is formed at the bottom of the heat shield 23. EUV light 6 emitted by the plasma P is incident on the left side of the heat shield 23 and passes through apertures KA and KB. Therefore, the shape of the EUV light 6 emitted to the right side of the heat shield 23 corresponds to the shape of apertures KA and KB.

[0077] In this way, a portion of the EUV light 6 emitted from the plasma P is extracted by apertures KA and KB. For example, the shapes of apertures KA and KB can be appropriately set to a circular shape or other shape to match the shape of the EUV light 6 to be extracted. Of course, the specific shapes of apertures KA and KB are not limited.

[0078] Furthermore, the heat shield 23 is made of a high-melting-point metal such as tungsten (W) or molybdenum (Mo). The specific material, shape, and other configurations of the heat shield 23 are not limited. The heat shield 23 corresponds to one embodiment of the aperture member according to this technology.

[0079] The rotary wheel trap 22 captures debris DB emitted from the plasma P. The rotary wheel trap 22 includes a cover member 25, a plurality of rotating wheels 51, an outer ring 52, a central support column 53, and a motor MC. Figure 3 is a schematic diagram showing an example of the configuration of the rotary wheel trap 22. Figure 3 shows the rotating wheel trap 22, including the multiple rotating wheels 51, the outer ring 52, and the central support column 53, as viewed from the left side (the side where the EUV light 6 is incident) in Figures 1 and 2.

[0080] The outer ring 52 is a ring-shaped component. The outer ring 52 is positioned concentrically with the central support 53. The rotating wheel 51 is a thin film or a thin flat plate. Each rotating wheel 51 is positioned between the outer ring 52 and the central support 53. Each rotating wheel 51 is arranged radially with approximately equal angular spacings relative to the central support 53. Therefore, each rotating wheel 51 lies on a plane containing the central axis JM of the central support 53. The rotating wheel 51, outer ring 52, and central support 53 are configured such that as you move from the outer circumference towards the center, the position of each component protrudes to the right side in Figures 1 and 2 (towards the back in Figure 3).

[0081] The rotating wheel 51, outer ring 52, and central support 53 are made of a high-melting-point metal such as tungsten or molybdenum. The specific composition of the materials for the rotating wheel 51, outer ring 52, and central support 53 is not limited.

[0082] The motor MC rotates the rotating wheel 51, the outer ring 52, and the central support column 53. The motor MC has a rotating shaft JC. The base of the motor MC is located on the right side outside the connection chamber 21, and the rotating shaft JC connected to the base extends from the outside to the inside of the connection chamber 21. The inner end of the rotating shaft JC on the connection chamber 21 is connected to the center of the right side face of the central support column 53.

[0083] The gap between the rotating shaft JC and the wall of the connecting chamber 21 is sealed by the sealing member PC. The sealing member PC maintains the reduced pressure atmosphere in the connecting chamber 21 while supporting the rotating shaft JC so that it can rotate freely.

[0084] The central axis JM of the central support column 53 coincides with the central axis of the rotation axis JC. That is, the rotation axis JC can be considered as the rotation axis of the rotating wheel 51, the outer ring 52, and the central support column 53. The rotating wheel 51, the outer ring 52, and the central support column 53 rotate together as a unit driven by the motor MC.

[0085] The cover member 25 is a member that surrounds the rotating wheel 51, the outer ring 52, and the central support column 53. In this embodiment, the cover member 25 has a shape that is generally similar to the rotating wheel 51, the outer ring 52, and the central support column 53.

[0086] The cover member 25 has an internal space 8, in which the rotating wheel 51, outer ring 52, and central support column 53 are arranged. A through hole 7 protruding to the right is formed in the center of the right side surface of the cover member 25, into which the rotating shaft JC of the motor MC is inserted. In addition, a discharge pipe 26 protruding downwards is formed at the lower part of the cover member 25.

[0087] Furthermore, an opening KI is formed on the left side of the cover member 25. The opening KI extends over almost the entire area of ​​the left side of the cover member 25. An opening KOA is formed on the upper part of the right side of the cover member 25. An opening KOB is formed on the lower part of the right side of the cover member 25.

[0088] The apertures KI, KOA, and KOB all have shapes that do not obstruct the propagation of EUV light 6. In Figure 2, the region through which EUV light 6 propagates is shown by a dashed line. The shapes of apertures KI, KOA, and KOB include the region through which EUV light 6 propagates. That is, the EUV light 6 passes through aperture KI, travels through the internal space 8 of the cover member 25, passes through apertures KOA and KOB, and travels to the outside of the rotating wheel trap 22, but the propagation of EUV light 6 is not obstructed by the cover member 25 during this time.

[0089] The specific shapes of openings KI, KOA, and KOB are not limited. Opening KI corresponds to one embodiment of the inlet of the cover member according to this technology. Openings KOA and KOB correspond to one embodiment of the outlet of the cover member according to this technology.

[0090] Figures 4 and 5 are schematic diagrams showing an example configuration of the fixed foil trap 24 in the reference example. The fixed foil trap 24 in this technology will be described later in the first embodiment.

[0091] Figure 4 shows the fixed wheel trap 24 as viewed from the positive side in the Z direction (upper side of Figure 2). Note that the housing portion 60 is not shown in Figure 4. Figure 5 shows a cross-section of the fixed wheel trap 24 when cut in the YZ plane, as viewed from the negative side in the X direction (left side of Figure 2). Note that in Figure 2 the fixed wheel trap 24 is positioned at a slight incline, but for the sake of easier understanding of the explanation, in Figures 4 and 5, the fixed wheel trap 24 is assumed to be not inclined with respect to the X, Y, and Z directions.

[0092] The fixed-type foil trap 24 has a housing 60 and a plurality of foils 61. The housing 60 has a rectangular parallelepiped shape. A rectangular inlet 62 is formed on the left side of the housing 60. A rectangular outlet 63 is formed on the right side of the housing 60. The housing 60 also has an internal space 9, which is enclosed by four surfaces: the front, back, top, and bottom (right, left, top, and bottom in Figure 6).

[0093] The fixed wheel trap 24 is positioned so that the opening KOA of the rotary wheel trap 22 and the inlet 62 of the fixed wheel trap 24 face each other. The specific configuration of the housing 60, such as its shape and material, is not limited.

[0094] The multiple foils 61 are thin films or thin flat plates. Each foil 61 is placed in the internal space 9 of the housing 60. Each foil 61 is placed at equal intervals in the Y direction. Furthermore, as shown in Figure 4, each foil 61 is arranged radially such that the spacing between the foils 61 increases towards the positive side in the Z direction. That is, the central foil 61 is placed parallel to the XZ plane, and the other foils 61 are placed at a slight inclination in the Y direction. The upper and lower edges of the foils 61 (the front edge and the back edge in Figure 4) are fixed to the inner surface of the housing 60.

[0095] The foil 61 is made of a high-melting-point metal such as tungsten or molybdenum. The specific composition of the foil 61, including the material, number, and arrangement, is not limited.

[0096] The debris containment section 4 is a container for containing debris DB. The debris containment section 4 includes a debris containment container 31 and heater wiring 34. The debris containment container 31 has a rectangular parallelepiped shape. A rectangular opening surrounded by a flange 32 is formed on the upper surface of the debris containment container 31. The debris containment container 31 is connected to the connection chamber 21 such that the flange 32 overlaps the opening 37 of the connection chamber 21. Specifically, for example, the flange 32 is fixed to the connection chamber 21 by screws. The gap between the flange 32 and the connection chamber 21 is sealed by a gasket 33. Of course, the specific configuration of the debris containment container 31, such as the material and shape, and the method of connection to the connection chamber 21, is not limited.

[0097] The heater wiring 34 heats the debris containment container 31. In this embodiment, the heater wiring 34 is wrapped around the debris containment container 31. However, it is not limited to this, and other heating means may be embedded in the debris containment container 31.

[0098] The debris guide section 5 guides the debris DB to the debris containment section 4. The debris guide section 5 has a receiving plate member 18 and a support base 44. The support base 44 is located in the lower left corner inside the connection chamber 21, tilted to the lower right.

[0099] The receiving plate member 18 is a member that serves as a receiving plate for the debris DB. The receiving plate member 18 is placed on the support base 44. The receiving plate member 18 has a rectangular shape. The receiving plate member 18 is positioned so that its left side penetrates the first window portion 17 and slightly protrudes into the interior of the chamber 11. The receiving plate member 18 is also positioned so that its right side is located near the opening 37. The specific configuration of the receiving plate member 18, such as its shape and material, is not limited.

[0100] [Progression of EUV light] The propagation of EUV light 6 emitted from the light source unit 2 will now be explained. In the light source unit 2, EUV light 6 emitted from the plasma P passes through the first window unit 17 and propagates into the interior of the connection chamber 21. The EUV light 6 first reaches the heat shield plate 23. A portion of the EUV light 6 is blocked by the heat shield plate 23, and a portion passes through the apertures KA and KB. Therefore, EUV light 6 with a shape corresponding to the shape of the apertures KA and KB is emitted to the right of the heat shield plate 23.

[0101] Next, the EUV light 6 enters the rotating wheel trap 22 through the opening KI of the cover member 25. In the internal space 8 of the cover member 25, multiple rotating wheels 51 are mounted so as to be rotatable relative to the region of the internal space 8 through which the EUV light 6 travels. That is, multiple rotating wheels 51 rotate in the region through which the EUV light 6 travels. For example, the rotation of the rotating wheels 51 is controlled by the drive of the motor MC by the control unit 12.

[0102] Each rotating wheel 51 is positioned parallel to the direction of propagation of the EUV light 6. Therefore, the EUV light 6 is blocked only by the thickness of the rotating wheel 51, and the majority of the EUV light 6 is emitted outside the rotating wheel trap 22. This arrangement of the rotating wheels 51 makes it possible to maximize the proportion (also called transmittance) of EUV light 6 that passes through the rotating wheel trap 22.

[0103] EUV light 6 emitted from the aperture KOA to the outside of the rotating foil trap 22 enters the entrance port 62 of the fixed foil trap 24. It then travels through the internal space 9 of the housing 60. In the internal space 9, multiple foils 61 are fixed in the region of the internal space 9 through which the EUV light 6 travels.

[0104] Each foil 61 is positioned parallel to the direction of propagation of the EUV light 6. Therefore, the EUV light 6 is blocked only by the thickness of the foil 61, and the majority of the EUV light 6 is emitted outside the fixed foil trap 24.

[0105] The EUV light 6 emitted from the outlet 63 of the fixed foil trap 24 passes through the second window section 27 and is emitted toward the utilization device 42. The utilization device 42 is a device that utilizes the EUV light 6. In other words, considering the overall operation of the light source device 1, it can be said that the light emitted from the plasma P is extracted by the second window section 27 and utilized by the utilization device 42. The second window section 27 corresponds to one embodiment of the light extraction unit according to this technology.

[0106] Meanwhile, the EUV light 6 that has passed through aperture KB passes through the lower part of the rotating foil trap 22 and is emitted from aperture KOB. Furthermore, the EUV light 6 enters the EUV light guide hole 28 and passes inside the guide tube 29.

[0107] A monitoring device 43 is provided at the outlet of the guide tube 29. The monitoring device 43 is a detector that detects EUV light 6 or a measuring instrument that measures the intensity of EUV light 6. For example, the emission intensity and emission timing of EUV light 6 may be controlled based on the monitoring results from the monitoring device 43.

[0108] [Debris capture] The specific details regarding the capture of debris DB by the debris reduction device 3 will be explained. Debris DB is emitted from the plasma P along with EUV light 6. The debris DB is emitted in various directions, and some of it passes through the first window section 17 and enters the inside of the connection chamber 21.

[0109] A portion of the debris DB that enters the connection chamber 21 accumulates on the left side of the heat shield 23. The debris DB accumulated on the heat shield 23 melts due to radiation from the plasma P, and when it reaches a certain amount, it turns into droplets and moves to the bottom of the heat shield 23 by gravity. The debris DB then detaches from the heat shield 23 and is contained in the debris containment container 31 located below the heat shield 23. Figure 2 schematically illustrates how the debris DB, which has turned into droplets on the heat shield 23, flows into the debris containment container 31.

[0110] The placement of the heat shield 23 reduces the amount of debris DB advancing into the rotating wheel trap 22. This reduces the load on the rotating wheel trap 22. In addition, the heat shield 23 suppresses heat conduction from the plasma P to the rotating wheel trap 22, preventing overheating of the rotating wheel trap 22. Furthermore, since the heat shield 23 is made of a high melting point material, deformation due to the heat of the plasma P is minimal.

[0111] On the other hand, some of the debris DB passes through openings KA and KB and proceeds to the right side of the heat shield 23. These debris DBs enter the rotating wheel trap 22. Inside the rotating wheel trap 22, the rotating wheel 51 is rotating, and the rotating wheel 51 actively collides with the debris DBs. As a result, the debris DBs are captured by the rotating wheel 51.

[0112] The debris DB captured by the rotating wheel 51 moves radially along the rotating wheel 51 due to centrifugal force, detaches from the end of the rotating wheel 51, and adheres to the inner surface of the cover member 25. In this way, since the rotating wheel 51 is surrounded by the cover member 25, scattering of the debris DB into the connection chamber 21 is prevented.

[0113] The cover member 25 is heated by a heating means (not shown), or by secondary radiation from the heat shield plate 23 that receives EUV radiation. When the cover member 25 is heated, the debris DB adhering to the inner surface of the cover member 25 does not solidify and maintains a liquid state. The debris DB adhering to the inner surface of the cover member 25 is collected at the bottom of the cover member 25 by gravity and discharged from the bottom of the cover member 25 through the discharge pipe 26 to the outside of the cover member 25 and into the debris containment container 31. Figure 2 schematically illustrates how the debris DB discharged from the discharge pipe 26 flows into the debris containment container 31.

[0114] The rotating wheel trap 22 captures debris DB moving at relatively low speeds. Therefore, debris DB moving at high speeds may not be captured by the rotating wheel trap 22, but may pass through the opening KOA and proceed to the right of the rotating wheel trap 22. These debris DBs enter the fixed wheel trap 24 from the entrance 62. Then, the debris DBs collide with the wheels 61. In this way, debris DBs moving at high speeds that were not captured by the rotating wheel trap 22 are captured by the fixed wheel trap 24.

[0115] [Collection of waste materials] Of the plasma raw material SA (tin) adhering to the discharge electrode EA and transported to the discharge region D, only a small amount of plasma raw material SA vaporizes upon irradiation with the energy beam and is used to generate plasma P. Therefore, most of the plasma raw material SA adhering to the discharge electrode EA is returned to container CA unused, but some of it falls due to gravity and does not return to container CA. Furthermore, due to some malfunction, some of the liquid-phase plasma raw material SA stored in container CA may overflow from container CA. Similarly, some of the plasma raw material SB may overflow from container CB.

[0116] As the waste material falls in the direction of gravity, it is received by the receiving plate member 18. The receiving plate member 18 is heated by a heating means (not shown) and maintained at a temperature above the melting point of tin (approximately 232°C), which is the waste material. Therefore, the waste material, still in liquid phase, moves along the receiving surface of the inclined receiving plate member 18 and flows into the debris containment container 31.

[0117] Figure 2 schematically illustrates the state in which the debris containment container 31 is filled with waste materials and debris DB. Since the waste materials are tin, and the majority of the debris DB is also tin, the debris containment container 31 can also be called a tin recovery container.

[0118] While the light source device 1 is operating, power is supplied to the heater wiring 34, and the inside of the debris containment container 31 is heated to a temperature above the melting point of tin. Consequently, the tin accumulated inside the debris containment container 31 becomes liquid.

[0119] When tin solidifies inside the debris containment container 31, the accumulated material in areas of the debris containment container 31 where debris DB is likely to fall grows like stalagmites in a cave. When the accumulated debris DB grows into a stalagmite-like structure, for example, the discharge pipe 26 of the cover member 25 may be blocked by the debris DB, causing the debris DB to accumulate inside the cover member 25. Furthermore, the debris DB accumulated inside the cover member 25 may come into contact with the rotating wheel trap 22, hindering its rotation or damaging it.

[0120] Alternatively, a portion of the openings KOA and KOB provided in the cover member 25 may be blocked by debris DB accumulated inside the cover member 25, thereby hindering the propagation of EUV light 6 in the openings KOA and KOB.

[0121] To prevent this from happening, heating keeps the tin in a liquid state. This flattens the tin within the debris storage container 31, allowing it to accumulate while avoiding stalagmite-like growth.

[0122] When recovering the tin accumulated in the debris containment container 31, the power supply to the heater wiring 34 is stopped, and the heating inside the debris containment container 31 is halted. Then, once the temperature of the debris containment container 31 returns to room temperature and the stored tin has solidified, the air pressure inside the connection chamber 21 is returned to atmospheric pressure. After that, the debris containment container 31 is removed from the connection chamber 21, and a new debris containment container 31, which does not contain any tin, is installed in the connection chamber 21.

[0123] The tin inside the removed debris containment container 31 is in a solid phase, but by reheating the debris containment container 31 and converting the tin inside back into a liquid phase, it is possible to remove the tin from the debris containment container 31. In this way, the removed debris containment container 31 can be reused.

[0124] <First Embodiment> Referring to Figures 6 to 12, a more detailed embodiment of the light source device 1 according to this technology will be described. In the following description, parts that are similar to the configuration and operation of the light source device 1 described above will be omitted or simplified.

[0125] [Fixed-type foil trap] The following describes the configuration of the fixed foil trap 24 related to this technology in more detail. Figures 6-8 are schematic diagrams showing examples of the configuration of a fixed wheel trap 24. Figure 6 shows a cross-section of the fixed wheel trap 24 when cut by a plane parallel to the XZ plane, as viewed from the front side of Figure 2. Figure 7 shows the fixed wheel trap 24 as viewed from the direction of arrow A in Figure 6. Figure 8 shows a cross-section of the fixed wheel trap 24 on the BB plane of Figure 6, as viewed from above. Note that the housing portion 60 is not shown in Figure 8.

[0126] The fixed foil trap 24 further includes an inlet 70 and a pressure regulating plate 71. The inlet 70 is a hole for introducing gas into the internal space 9 of the fixed foil trap 24. The inlet 70 is configured to communicate with the internal space 9 of the housing 60. Specifically, five inlet 70 are arranged at equal intervals in the Y direction, slightly to the left of the center (lower side in Figure 8) of the upper surface (front side in Figure 8) and lower surface (back side in Figure 8) of the housing 60. Of course, the specific configuration, such as the number and position of the inlet 70, is not limited. In addition, gas is supplied to the inlet 70 by a gas supply means, for example, which is not shown in Figure 2, via gas piping (not shown) connecting the gas supply means and the inlet 70. If the gas supply means is located outside the connection chamber 21, the gas piping is introduced from the gas supply means into the connection chamber 21 via a feedthrough provided in the connection chamber 21 so as not to disrupt the pressure atmosphere (reduced pressure atmosphere) inside the connection chamber.

[0127] In this embodiment, argon (Ar) gas 80 is introduced through the inlet 70. For example, the control unit 12 controls the operation of a mechanism (not shown) for introducing the argon gas 80 (e.g., the gas supply means described above). The argon gas 80 is a transparent gas that is transparent to EUV light 6. That is, the propagation of EUV light 6 is not hindered by the argon gas 80 (for example, reflection or refraction of the EUV light 6 occurs). Note that other types of transparent gases such as helium (He) or hydrogen (H2) may be introduced.

[0128] The pressure regulating plate 71 is a component that increases the pressure in the internal space 9. The pressure regulating plate 71 is plate-shaped and has a circular opening 72 in the center. The pressure regulating plate 71 is fitted over the entire outlet port 63 of the housing portion 60. That is, the outlet port 63 is sealed by the pressure regulating plate 71 in a state where the portion other than the opening 72 is sealed. In this way, the pressure regulating plate 71 is positioned in the outlet port 63 so that the opening area of ​​the outlet port 63 is reduced.

[0129] Furthermore, the shape of the opening 72 of the pressure adjustment plate 71 is set so as not to obstruct the propagation of EUV light 6. In this embodiment, as shown in Figure 7, since the region in which EUV light 6 propagates at the position of the pressure adjustment plate 71 is circular, the shape of the opening 72 is set to be a circular shape with a diameter slightly larger than the region in which EUV light 6 propagates. As a result, the propagation of EUV light 6 is not obstructed by the pressure adjustment plate 71.

[0130] Furthermore, among the EUV light 6 traveling inside the light source device 1, there may be some EUV light 6 that is ultimately used by the utilization device 42 and some that is not used. In such cases, the pressure adjustment plate 71 should be configured so as not to obstruct the propagation of the necessary light that is ultimately used. In other words, a configuration that does not obstruct the propagation of the necessary light is included in the configuration that does not obstruct the propagation of EUV light 6 in this technology.

[0131] The specific shape of the opening 72 of the pressure adjustment plate 71 is not limited. For example, any shape that does not obstruct the propagation of EUV light 6, such as a rectangular shape, may be adopted. The pressure adjustment plate 71 corresponds to one embodiment of the output side member and cover member according to this technology. Furthermore, the pressure adjustment plate 71 realizes the pressure increase mechanism according to this technology.

[0132] Furthermore, each wheel 61 has an opening 73. As shown in Figure 6, the opening 73 is rectangular in shape and is located in the center of the wheel in the Z direction, at the same position as the inlet hole 70 in the X direction. That is, as shown in Figure 8, each opening 73 forms a buffer space 74 which has a rectangular parallelepiped shape and does not contain any wheel 61. Each inlet hole 70 communicates with the buffer space 74.

[0133] [Configuration with two pressure adjustment plates] Figures 9 and 10 are schematic diagrams showing examples of the configuration of a pressure regulating plate. Figure 10 is a cross-sectional view of the fixed wheel trap 24 on the CC surface shown in Figure 9. Note that the housing portion 60 is not shown in Figure 10. As shown in Figures 9 and 10, pressure adjustment plates may be provided at the inlet 62 and outlet 63 of the housing portion 60, respectively.

[0134] In this example, the fixed wheel trap 24 further includes a pressure regulating plate 88. The pressure regulating plate 88 is plate-shaped, similar to the pressure regulating plate 71, and has a circular opening 89 in the center. The pressure regulating plate 88 is fitted over the entire entrance port 62 of the housing 60. That is, the entrance port 62 is sealed by the pressure regulating plate 88 in all areas except the opening 89. In this way, the pressure regulating plate 88 is positioned in the entrance port 62 so as to reduce the opening area of ​​the entrance port 62.

[0135] The shape of the opening 89 of the pressure regulating plate 88 is set to not obstruct the propagation of EUV light 6, similar to the shape of the opening 72 of the pressure regulating plate 71. In this example, the shapes of the openings 72 and 89 are the same circular shape, but their shapes may be different. The pressure regulating plate 88 corresponds to one embodiment of the incident side member and cover member according to this technology. Furthermore, the pressure regulating plate 71 and the pressure regulating plate 88 realize the pressure increasing mechanism according to this technology.

[0136] Alternatively, a configuration may be adopted in which a pressure regulating plate 88 is installed only at the inlet 62, without a pressure regulating plate 71 at the outlet 63.

[0137] By introducing argon gas 80 into the internal space 9 of the fixed wheel trap 24, the probability of capturing debris DB can be increased. Specifically, in the space where argon gas 80 is present, collisions between the debris DB and the argon gas 80 reduce the speed of the debris DB. Also, the collisions change the direction of the debris DB's movement. Debris DB whose speed has decreased and whose direction of movement has changed in this way is captured by the wheel 61 and the housing 60. In other words, more debris DB is captured compared to when transparent gas is not introduced into the internal space 9 of the fixed wheel trap 24.

[0138] Furthermore, in this embodiment, an inlet 70 for introducing argon gas 80 is provided. This makes it possible to increase the pressure of the argon gas 80 in the internal space 9. Figure 11 is a schematic diagram showing the flow of argon gas 80 in the comparative example debris reduction device 77.

[0139] In the comparative example debris reduction device 77, argon gas 80 is introduced from above the gap between the rotating wheel trap 78 and the fixed wheel trap 79. Figure 11 schematically illustrates the direction in which the introduced argon gas 80 diffuses with dashed arrows.

[0140] Argon gas 80 is introduced, for example, by a gas nozzle (not shown). The argon gas 80 introduced from the upper side of the gap diffuses downwards within the gap. As it diffuses, the pressure of the argon gas 80 decreases in the lower part of the gap. Therefore, the upper part of the gap becomes a region with a relatively high pressure of argon gas 80. In Figure 11, the region with a relatively high pressure of argon gas 80 is shown by a dot pattern.

[0141] The gap is in communication with the internal space 83 of the fixed foil trap 79. Therefore, the argon gas 80 enters the internal space 83 from the inlet 81 of the fixed foil trap 79 and diffuses within the internal space 83. However, the argon gas 80 present in the upper part of the gap has a higher pressure and is therefore more likely to flow into the upper part of the internal space 83. On the other hand, the argon gas 80 present in the lower part of the gap has a lower pressure and is less likely to flow into the lower part of the internal space 83. Consequently, the pressure of the argon gas 80 is relatively higher in the upper part of the internal space 83 compared to the lower part.

[0142] Thus, a pressure difference in the argon gas 80 occurs even within the internal space 83. In other words, the pressure distribution of the argon gas 80 in the region where the EUV light 6 is transmitted becomes non-uniform, resulting in a spatial distribution (non-uniformity) in the debris DB capture capacity of the fixed foil trap 79.

[0143] Furthermore, the gap is in communication with the internal space 82 of the rotary wheel trap 78. Therefore, the argon gas 80 enters the internal space 82 through the opening KOA of the rotary wheel trap 78 and diffuses in the internal space 82.

[0144] In the fixed foil trap 79, the internal space 83 is divided by each foil 84. Therefore, argon gas 80 flows more easily into the fixed foil trap 79 than into the rotating foil trap 78, but less easily into the fixed foil trap 79. In other words, sufficient pressure of argon gas 80 cannot be obtained in the fixed foil trap 79, and the debris DB capture capacity cannot be improved.

[0145] In the debris reduction device 3 of this embodiment, argon gas 80 is directly introduced into the internal space 9 of the fixed wheel trap 24 through the inlet hole 70. As a result, the pressure distribution of the argon gas 80 in the internal space 9 does not become uneven. Furthermore, it is possible to maintain a high pressure of the argon gas 80 in the internal space 9. In other words, it is possible to improve the probability of capturing debris DB by the fixed wheel trap 24.

[0146] Furthermore, the placement of the pressure adjustment plate 71 makes it possible to increase the pressure of the argon gas 80 in the internal space 9. In the comparative example, the fixed foil trap 79, the incoming argon gas 80 diffuses to the right in the internal space 83 and flows out from the outlet 85. On the other hand, in the fixed foil trap 24 of this embodiment, a part of the outlet 63 is sealed by the pressure adjustment plate 71, so the outflow of argon gas 80 is suppressed. Consequently, the pressure of the argon gas 80 in the internal space 9 increases.

[0147] Furthermore, the placement of the pressure adjustment plate 71 makes it possible to increase the pressure of the argon gas 80 in the rotary wheel trap 22. Figure 12 is a schematic diagram showing the flow of argon gas 80 in the debris reduction device 3 of this technology.

[0148] The fixed foil trap 24 does not have a pressure regulating plate 71 at the inlet 62, but only at the outlet 63. Therefore, the argon gas 80 introduced from the inlet hole 70 tends to flow towards the inlet 62. As a result, the area near the inlet 62 within the internal space 9 is a region with relatively high pressure of argon gas 80. In Figure 12, the region with relatively high pressure of argon gas 80 is shown as a dotted pattern.

[0149] Consequently, the argon gas 80 that flows out from the inlet 62 at a relatively high pressure enters the internal space 8 through the opening KOA of the rotary wheel trap 22. As a result, argon gas 80 is also introduced into the rotary wheel trap 22, further improving its debris DB capture performance.

[0150] When two pressure regulating plates 71 and 88 are provided, the argon gas 80 is less likely to flow out from the inlet 62, and the pressure of the argon gas 80 in the internal space 9 increases further. In other words, the probability of capturing debris DB can be further improved.

[0151] Furthermore, in the debris reduction device 3 of this embodiment, a buffer space 74 is formed in the internal space 9 of the fixed foil trap 24. The argon gas 80 introduced from the inlet hole 70 first diffuses within the buffer space 74. Then, it flows into the gaps between the respective foils 61 located on the left and right sides (up and down in Figure 8, in the X direction) of the buffer space 74. The argon gas 80 then diffuses in the X direction within the gaps between the foils 61. In Figure 8, the direction of diffusion of the argon gas 80 in the gaps between the foils 61 is schematically shown by arrows.

[0152] The argon gas 80 temporarily remains in the buffer space 74, and after the pressure becomes uniform, it flows into the gaps between each wheel 61. Therefore, there is little difference in the pressure of the argon gas 80 in each gap. The formation of the buffer space 74 makes the pressure of the argon gas 80 in the internal space 9 uniform, further improving the probability of capturing debris DB.

[0153] Furthermore, in this embodiment, debris is captured by both the rotating wheel trap 22 and the fixed wheel trap 24. This allows for the capture of both slow-moving and fast-moving debris DB compared to the case where only one of the rotating wheel trap 22 or the fixed wheel trap 24 is provided, thus improving the probability of capturing debris DB.

[0154] Furthermore, in this embodiment, a heat shield 23 is placed between the plasma P and the rotating wheel trap 22. By appropriately setting the shape of the opening KA of the heat shield 23, it is possible to arbitrarily change the shape of the EUV light 6 emitted from the light source device 1. In addition, it is possible to reduce the amount of debris DB advancing into the rotating wheel trap 22. Moreover, it is possible to prevent overheating of the rotating wheel trap 22 and other components due to the heat of the plasma P.

[0155] In the debris reduction device 3 according to this embodiment, a plurality of wheels 61 are arranged in the internal space 9 of the housing 60. Transparent gas is also introduced into the internal space 9. Furthermore, a pressure adjustment plate 71 is provided to increase the pressure in the internal space 9. This makes it possible to improve the probability of capturing debris DB.

[0156] EUV light sources emit extreme ultraviolet (EUV) light with a wavelength of approximately 13.5 nm. Such EUV light is used, for example, in lithography during semiconductor device manufacturing. Alternatively, EUV light is used as inspection light for mask blank inspection and pattern inspection. Thus, EUV light sources are sometimes used in mask inspection equipment. The use of EUV light makes it possible to support 5 nm to 7 nm processes.

[0157] However, in EUV light sources, debris is emitted along with the EUV light. When debris reaches the user's equipment, it can damage or contaminate the reflective coatings of optical elements within the equipment, degrading its performance. Therefore, a debris reduction device is incorporated into the EUV light source to capture the debris and prevent it from entering the user's equipment. Technologies to improve the debris capture performance of such debris reduction devices are needed.

[0158] In the debris reduction device 3 of this technology, the pressure of the argon gas 80 in the internal space 9 is increased by the placement of the pressure adjustment plate 71. This makes it possible to achieve high capture performance by the debris reduction device 3.

[0159] <Second Embodiment> Referring to Figures 13 to 15, a light source device 1 of a second embodiment of this technology will be described. In the following description, parts that are similar to the configuration and operation of the light source device 1 described in the above embodiment will be omitted or simplified.

[0160] [Cavity limiting member] Figures 13-15 are schematic diagrams showing examples of the configuration of cavity limiting members. Figure 14 shows the fixed wheel trap 24 as viewed from the direction of arrow D shown in Figure 13. Figure 15 is a cross-sectional view of the fixed wheel trap 24 in the EE plane of Figure 13. Note that the housing portion 60 is not shown in Figure 15. As shown in Figures 13-15, a cavity limiting member may be provided at the outlet 63 of the housing portion 60.

[0161] In this example, the fixed wheel trap 24 has a cavity limiting member 91. The cavity limiting member 91 has a block-like shape. Specifically, the cavity limiting member 91 is generally rectangular in shape. The cavity limiting member 91 also has an opening 92. The opening 92 is configured to communicate with two opposing surfaces of the cavity limiting member 91. The shape of the opening 92 is set to not obstruct the propagation of EUV light 6, similar to the shape of the opening 72 of the pressure adjustment plate 71.

[0162] The cavity limiting member 91 is positioned at the injection port 63 of the housing portion 60. Specifically, the cavity limiting member 91 is embedded in the internal space 9 of the housing portion 60 such that its opening 92 faces the injection port 63. In other words, the cavity limiting member 91 is positioned to fill the internal space 9. The specific shape of the cavity limiting member 91 is not limited, and any block-like shape may be adopted. For example, the shape of the cavity limiting member 91 is appropriately set to match the shape of the housing portion 60 so that the cavity limiting member 91 can be embedded in the housing portion 60 without any gaps. Furthermore, the specific thickness of the cavity limiting member 91 is not limited.

[0163] The cavity limiting member 91 has grooves into which each wheel 61 is fitted. Figure 14 schematically shows the state in which the wheels 61 are fitted into the grooves. In the region of the internal space 9 where the cavity limiting member 91 is present, the wheels 61 are fixed to the cavity limiting member 91 in this manner. In the region where the cavity limiting member 91 is not present, the wheels 61 are fixed to the housing portion 60.

[0164] The placement of the cavity limiting member 91 reduces the volume of the internal space 9. Furthermore, it becomes more difficult for argon gas 80 to leak out from the outlet 63. This makes it possible to maintain an even higher pressure of argon gas 80 in the fixed foil trap 24.

[0165] The cavity limiting member 91 can be considered as having a shape in which the length of the opening 72 of the pressure regulating plate 71 in the direction in which the gas flows is extended. Therefore, the conductance of the cavity limiting member 91 is smaller than the conductance of the opening 72 of the pressure regulating plate 71 on which the outlet port 63 is located. Thus, as described above, arranging the cavity limiting member 91 makes it possible to increase the pressure of the argon gas 80 in the internal space 9 compared to arranging the pressure regulating plate 71 at the outlet port 63.

[0166] Any combination of the following arrangements of the pressure adjustment plate 71 and the cavity limiting member 91 may be adopted. (1) No placement at the inlet 62, pressure adjustment plate 71 at the outlet 63 (2) No cavity limiting member 91 at the inlet 62, and no cavity limiting member 91 at the outlet 63 (3) Pressure adjustment plate 88 at the inlet 62, not at the outlet 63 (4) Pressure adjustment plate 88 at the inlet 62, pressure adjustment plate 71 at the outlet 63 (5) Pressure adjustment plate 88 at the inlet 62, cavity limiting member 91 at the outlet 63 (6) No cavity limiting member 91 is placed at the inlet 62, and no member is placed at the outlet 63. (7) Cavity limiting member 91 at the inlet 62, pressure adjustment plate 71 at the outlet 63 (8) Cavity limiting member 91 at the entrance port 62, cavity limiting member 91 at the exit port 63

[0167] The cavity limiting member 91 corresponds to one embodiment of the inlet-side member, outlet-side member, and block member according to this technology. Furthermore, the pressure increasing mechanism according to this technology is realized by the cavity limiting member 91.

[0168] <Other Embodiments> This technology is not limited to the embodiments described above, and various other embodiments can be realized.

[0169] [Space connection member] Figure 16 is a schematic diagram showing an example of the configuration of a spatial connection member. As shown in Figure 16, a spatial connecting member may be provided to connect the rotary wheel trap 22 and the fixed wheel trap 24.

[0170] In this example, the debris reduction device 3 has a space connecting member 94. The space connecting member 94 has, for example, a ring shape. Furthermore, the diameter of the opening of the ring of the space connecting member 94 is configured to be the same as the diameter of the inlet 62 of the fixed wheel trap 24.

[0171] The spatial connecting member 94 is positioned such that the ring portion of the spatial connecting member 94 seals the gap between the rotating wheel trap 22 and the fixed wheel trap 24. In other words, the spatial connecting member 94 connects the opening KOA of the rotating wheel trap 22 and the inlet 62 of the fixed wheel trap 24.

[0172] As a result, the argon gas 80 flowing out from the inlet 62 of the fixed wheel trap 24 flows entirely into the rotating wheel trap 22 without leaking out upwards or downwards in the gaps. In other words, it becomes possible to further increase the pressure of the argon gas 80 in the internal space 8 of the rotating wheel trap 22. The space connecting member 94 corresponds to one embodiment of the connecting member according to this technology.

[0173] [Anterior obstruction] Figure 17 is a schematic diagram showing an example of the configuration of the front closure section. As shown in Figure 17, the rotary wheel trap 22 may be provided with a front closing section.

[0174] In this example, the rotary wheel trap 22 further has a front closing portion 97. The front closing portion 97 is configured to seal the opening KI on the left side of the cover member 25. That is, the front closing portion 97 can also be considered as part of the cover member 25. The front closing portion 97 has a plate shape that is circular when viewed from the left side, and has a shape that protrudes to the right as it approaches the center of the circle.

[0175] The front closure portion 97 is configured with openings 98 and 99. Opening 98 is circular in shape and is located in the center of the front closure portion 97 in the Y direction and on the positive side in the Z direction. Opening 99 is circular in shape and is located in the center of the front closure portion 97 in the Y direction and on the negative side in the Z direction. The specific shapes and positions of openings 98 and 99 are not limited.

[0176] As a result, most of the opening KI of the cover member 25 is sealed, and the outflow of argon gas 80 that has flowed from the fixed wheel trap 24 into the rotary wheel trap 22 from the opening KI is suppressed. In other words, it becomes possible to maintain a high pressure of argon gas 80 in the rotary wheel trap 22.

[0177] The front closing portion 97 is positioned in the opening KI such that the opening area of ​​the opening KI is reduced. Therefore, the front closing portion 97 can also be considered as a pressure regulating plate 71 positioned in the rotary wheel trap 22. Similarly, the right side surface of the cover member 25 can also be considered as a pressure regulating plate 71. Alternatively, a cavity limiting member 91 may be positioned in the opening KI or on the right side surface of the cover member 25.

[0178] The front closing portion 97 corresponds to one embodiment of the inlet-side member and cover member according to this technology. Furthermore, the front closing portion 97 realizes the pressure increasing mechanism according to this technology.

[0179] [Addition of fixed foil traps] Figure 18 is a schematic diagram showing an example configuration in which a fixed wheel trap 24 is placed between a rotary wheel trap 22 and a monitoring device 43. As shown in Figure 18, a fixed wheel trap 24 may be added between the rotary wheel trap 22 and the monitoring device 43.

[0180] In this example, the debris reduction device 3 has fixed wheel traps 24 and 102. The fixed wheel trap 24 is positioned between the rotary wheel trap 22 and the utilization device 42, similar to the fixed wheel trap 24 shown in Figure 1, etc. The fixed wheel trap 24 is positioned between the rotary wheel trap 22 and the monitoring device 43. In other words, the fixed wheel traps 24 and 102 can also be said to be positioned between the plasma P and the utilization device 42, and between the plasma P and the monitoring device 43, respectively.

[0181] As a result, the debris DB is captured by the fixed wheel trap 102, and its advance toward the monitoring device 43 is suppressed. In other words, it is possible to prevent damage to the monitoring device 43 due to collision with the debris DB. In addition, since the argon gas 80 introduced into the fixed wheel trap 102 flows into the rotating wheel trap 22, it is possible to further increase the pressure of the argon gas 80 in the rotating wheel trap 22.

[0182] [Means for applying magnetic field] Figures 19-21 are schematic diagrams showing examples of the configuration of the magnetic field application means. Figure 19 shows a fixed foil trap 24 with a pressure adjustment plate 71 positioned at the outlet 63, equipped with a magnetic field applying means 105. Figure 20 shows a fixed foil trap 24 with a cavity limiting member 91 positioned at the outlet 63, equipped with a magnetic field applying means 105. As shown in Figures 19-21, the fixed foil trap 24 may be provided with a magnetic field applying means for applying a magnetic field.

[0183] In this example, the fixed foil trap 24 has a magnetic field applying means 105. The magnetic field applying means 105 is a means for applying a magnetic field to the surrounding space. For example, a permanent magnet can be used as the magnetic field applying means 105. The magnetic field applying means 105 is positioned above and below the entrance opening 62 of the housing portion 60.

[0184] The magnetic field applying means 105 generates a magnetic field that moves charged particles, which are excited by the EUV light 6, away from the multiple foils 61. That is, the charged particles move in various directions between each foil 61, but when a magnetic field is applied, for example, the direction of movement of the charged particles changes to the left. In this case, the charged particles pass through the entrance 62 and move outside the fixed foil trap 24. That is, they move away from the foils 61.

[0185] Alternatively, a magnetic field may be applied that changes the direction of travel of the charged particles to the right, moving the charged particles from the outlet 63 to the outside of the fixed foil trap 24. For example, the direction and strength of the magnetic field can be adjusted by appropriately setting the type (permanent magnet, electromagnet, etc.), position, or number of the magnetic field applying means 105.

[0186] The inventors observed that as the light source device 1 was operated, damage occurred to a portion of the wheel 61 of the fixed wheel trap 24. One possible cause of this damage is the collision of high-energy particles, such as debris DB (e.g., ions and electrons of the plasma raw material SA moving at high speed), with the wheel 61. However, it is thought that most of these high-energy, rapidly moving debris DBs become neutral particles by colliding with the relatively high-pressure argon gas 80 before colliding with the wheel 61, thereby reducing the energy of the debris DBs. Therefore, the main cause of the damage to the wheel 61 is not necessarily the collision between the wheel 61 and the debris DBs.

[0187] Upon investigating the damaged areas of the foil 61, it was confirmed that the damage to the foil 61 was particularly pronounced in regions where the pressure (density) of the argon gas 80 was relatively high, and near the region through which the EUV light 6 passed. From this trend, it is presumed that the damage to the foil 61 occurred when at least a portion of the argon gas 80 was excited by irradiation with EUV light 6, becoming relatively high-energy charged particles, and the foil 61 was damaged by contact between these charged argon particles and the foil 61.

[0188] In this example, the magnetic field applying means 105 is provided so that a magnetic field is applied to the region near the inlet 62, which is a region where the pressure (density) of the argon gas 80 is relatively high. This reduces the frequency of charged particles colliding with the wheel 61, thereby suppressing damage to the wheel 61.

[0189] Furthermore, an electric field applying means may be provided to generate an electric field that moves charged particles away from the multiple foils 61. By providing an electric field generating means, it is possible to similarly suppress damage to the foils 61. The magnetic field applying means 105 and the electric field applying means correspond to one embodiment of the electromagnetic field generating unit according to this technology.

[0190] [Buffer space location] Figure 22 is a schematic diagram showing an example of the configuration of the buffer space 74. Note that the housing portion 60 is not shown in Figure 22. The location of buffer space 74 can be set arbitrarily.

[0191] In this example, the buffer space 74 is configured such that its center in the left-right direction (up-down direction in Figure 22) is located at a distance L1 from the left end (bottom end in Figure 22) and a distance L2 from the right end (top end in Figure 22) of the wheel 61. Here, L1 is a smaller value than L2. In other words, the buffer space 74 is located to the left of the center of the internal space 9 (below it in Figure 22).

[0192] The foils 61 are arranged radially so as to extend in the direction of the EUV light rays 6, and the spacing between the foils 61 is narrower on the side of the EUV light inlet 62 and wider on the side of the outlet 63. Therefore, the argon gas 80 supplied from the inlet hole 70 into the compartmentalized space of the foils 61 tends to flow less toward the inlet 62 and more toward the outlet 63. Consequently, the pressure in the space near the outlet 63 tends to be higher than the pressure in the space near the inlet 62. In that case, the attenuation of the intensity of the EUV light 6 by the argon gas 80 may become significant in some cases.

[0193] Here, by bringing the position of the buffer space 74 closer to the incident port 62 side (that is, by setting L1 < L2), the pressure of the argon gas 80 in the downstream (right side) space in the passing region of the EUV light 6 can be made relatively low. In FIG. 22, the region with a relatively low pressure is indicated by a dashed ellipse. As a result, the optical path length of the space where the pressure of the argon gas 80 is high becomes shorter, and it becomes possible to suppress the attenuation of the intensity of the EUV light 6 by the argon gas 80. Note that the present invention is not limited to this example, and the buffer space 74 may be configured at an arbitrary position.

[0194] [Configuration of Debris Reduction Device] As the configuration of the debris reduction device 3, a configuration may be adopted in which only the fixed foil trap 24 is arranged without arranging the rotary foil trap 22. Of course, a configuration in which both the rotary foil trap 22 and the fixed foil trap 24 as shown in FIG. 1 are arranged may be adopted. Alternatively, a plurality of rotary foil traps 22 or fixed foil traps 24 may be arranged.

[0195] The configurations of the light source device, the light source unit, the debris reduction device, the rotary foil trap, and the fixed foil trap described with reference to each drawing are merely one embodiment, and can be arbitrarily modified without departing from the gist of the present technology. That is, any other arbitrary configuration for implementing the present technology may be adopted.

[0196] In this disclosure, where the word "abbreviated" is used, it is used solely to facilitate understanding of the explanation, and there is no special meaning in the use or non-use of the word "abbreviated". In other words, in this disclosure, concepts that define shape, size, positional relationships, state, etc., such as "center," "central," "uniform," "equal," "same," "orthogonal," "parallel," "symmetrical," "extending," "axial," "cylindrical," "cylindrical shape," "ring shape," "annular shape," "rectangular shape," "disk shape," "plate shape," "circular shape," "rectangular," "square shape," and "block shape," are considered to include concepts such as "substantially centered," "substantially central," "substantially uniform," "substantially equal," "substantially same," "substantially orthogonal," "substantially parallel," "substantially symmetrical," "substantially extending," "substantially axial," "substantially cylindrical," "substantially cylindrical shape," "substantially ring shape," "substantially annular shape," "substantially rectangular shape," "substantially disk shape," "substantially plate shape," "substantially circular shape," "substantially rectangular," "substantially rectangular shape," "substantially square shape," and "substantially block shape." For example, states that fall within a predetermined range (e.g., ±10%) based on criteria such as "perfectly centered," "perfectly central," "perfectly uniform," "perfectly equal," "perfectly the same," "perfectly orthogonal," "perfectly parallel," "perfectly symmetrical," "perfectly extending," "perfectly axial," "perfectly cylindrical," "perfectly cylindrical shape," "perfectly ring shape," "perfectly annular shape," "perfectly rectangular shape," "perfectly disk shape," "perfectly plate shape," "perfectly circular shape," "perfectly rectangular shape," "perfectly square shape," and "perfectly block shape" are also included. Therefore, even if the word "abbreviated" is not added, concepts that would normally be expressed with "abbreviated" added may be included. Conversely, the state expressed with "abbreviated" does not exclude the possibility of a perfect state.

[0197] In this disclosure, expressions using "greater than A" such as "greater than A" and "less than A" are expressions that comprehensively include both concepts that include cases where something is equivalent to A and concepts that do not include cases where something is equivalent to A. For example, "greater than A" is not limited to cases where something is not equivalent to A, but also includes "greater than or equal to A". Similarly, "less than A" is not limited to "less than A", but also includes "less than or equal to A". When implementing this technology, you may appropriately adopt specific settings from the concepts included in "greater than A" and "less than A" so that the effects described above are achieved.

[0198] It is also possible to combine at least two of the feature features of the present technology described above. In other words, the various feature features described in each embodiment may be combined arbitrarily, regardless of the specific embodiment. Furthermore, the various effects described above are merely examples and not limiting, and other effects may also be exhibited. [Explanation of symbols]

[0199] DB...Debris KA...Open KB…Aperture KI…Opening KOA…opening KOB…Opening P...Plasma 1...Light source device 2...Light source section 3…Debris reduction device 6…EUV light 8…Interior space 9…Interior space 22... Rotary foil trap 23… Heat shield 24... Fixed foil trap 25... Cover component 27…Second Window Section 42…Equipment used 43...Monitoring device 51... Rotating wheel 60... Enclosure 61... Foil 62...Incidence aperture 63... Exhaust port 70...Inflow hole 71... Pressure regulating plate 74... Buffer space 80...Argon gas 88... Pressure regulating plate 89…Aperture 91... Cavity limiting member 92…Aperture 94... Spatial connection member 97…Anterior occlusion 98…Aperture 99…Aperture 102... Fixed foil trap 105...Means for applying a magnetic field

Claims

1. A debris reduction device that captures debris emitted from a light source, A housing portion having an inlet into which light emitted from the light source enters, an outlet into which the light that entered from the inlet exits, and an internal space through which the light travels, A plurality of wheels fixed in the region of the internal space through which the light propagates, The housing portion is configured to communicate with the internal space and has an inlet hole through which a transparent gas that is transparent to light flows, A pressure increasing mechanism that increases the pressure in the internal space includes at least one of an inlet-side member positioned at the inlet so as to reduce the opening area of ​​the inlet without obstructing the propagation of the light, or an outlet-side member positioned at the outlet so as to reduce the opening area of ​​the outlet without obstructing the propagation of the light, and Sharp fixed foil trap A debris reduction device equipped with the following.

2. A debris reduction device according to claim 1, At least one of the incident side member or the outgoing side member is a lid member that is plate-shaped and has an opening through which the light passes. Debris reduction device.

3. A debris reduction device according to claim 1 or 2, At least one of the inlet-side member or the outlet-side member is a block-shaped block member having an opening through which the light passes and arranged to fill the internal space. Debris reduction device.

4. A debris reduction device according to claim 1 or 2, The fixed foil trap has an electromagnetic field generating unit that generates an electric field or magnetic field that moves charged particles, which are excited by the light, from the transparent gas away from the plurality of foils. Debris reduction device.

5. A debris reduction device according to claim 1 or 2, The internal space includes a buffer space where none of the plurality of wheels exist. The inlet is configured to communicate with the buffer space. Debris reduction device.

6. A debris reduction device according to claim 1 or 2, The fixed foil trap is positioned between the light source and the utilization device that utilizes the light emitted from the light source, and between the light source and the monitoring device that monitors the state of the light emitted from the light source. Debris reduction device.

7. A debris reduction device according to claim 1 or 2, The aforementioned light source is plasma. Debris reduction device.

8. A debris reduction device according to claim 1 or 2, further, A cover member having an inlet into which light emitted from the light source enters, an outlet into which the light that entered from the inlet exits, and an internal space through which the light travels, A plurality of rotating wheels are rotatably mounted with respect to the region in the internal space through which light travels. It is equipped with a rotary wheel trap. Debris reduction device.

9. A debris reduction device according to claim 8, The rotary wheel trap includes at least one of an inlet-side member positioned at the inlet so as to reduce the opening area of ​​the inlet without obstructing the propagation of light, or an outlet-side member positioned at the outlet so as to reduce the opening area of ​​the outlet without obstructing the propagation of light, and has a pressure increasing mechanism that increases the pressure in the internal space. Debris reduction device.

10. A debris reduction device according to claim 8, The fixed wheel trap and the rotary wheel trap are arranged so that the outlet of the rotary wheel trap and the inlet of the fixed wheel trap face each other. The debris reduction device further comprises a connecting member that connects the outlet of the rotating wheel trap and the inlet of the fixed wheel trap. Debris reduction device.

11. A debris reduction device according to claim 8, further, The system comprises an aperture member positioned between the light source and the rotating wheel trap, having an opening for extracting a portion of the light emitted from the light source. Debris reduction device.

12. A plasma generation chamber that excites light-emitting raw materials to generate plasma, A light extraction unit that extracts light emitted from the plasma, A debris reduction device having a fixed foil trap positioned between the plasma generation chamber and the light extraction unit, which captures debris emitted from the plasma, It is equipped with, The aforementioned fixed foil trap is A housing portion having an inlet into which light emitted from the plasma enters, an outlet into which the light that entered from the inlet exits, and an internal space through which the light travels, A plurality of wheels fixed in the region of the internal space through which the light propagates, The housing portion is configured to communicate with the internal space and has an inlet hole through which a transparent gas that is transparent to light flows, A pressure increasing mechanism that increases the pressure in the internal space includes at least one of an inlet-side member positioned at the inlet so as to reduce the opening area of ​​the inlet without obstructing the propagation of the light, or an outlet-side member positioned at the outlet so as to reduce the opening area of ​​the outlet without obstructing the propagation of the light, and A light source device having the following features.

13. A light source device according to claim 12, The debris reduction device is, A cover member having an inlet into which light emitted from the plasma enters, an outlet into which the light that entered from the inlet exits, and an internal space through which the light travels, Multiple rotating wheels are rotatably mounted in relation to the region through which light travels within the internal space. Having a rotary wheel trap Light source device.

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