Rotating disk structure for EUV light source device

Abstract

The present invention relates to a rotating disk that is driven to generate EUV light through a plasma reaction with a target material in an EUV light source device and confines the target material by centrifugal force, wherein the rotating disk comprises a plurality of rotating disk ribs that support the rotating disk rim to transmit to a predetermined area of ​​the concentrated EUV light, which is concentrated through a collector mirror to receive the EUV light reflected therefrom, which is irradiated onto the target material by penetrating a beam output from a racer source through the center and concentrated to the same incident light axis.

Description

Technology Field

[0001] The present invention relates to a rotating disk structure for an EUV light source device, and more specifically, to a rotating disk structure for an EUV light source device capable of significantly improving the amount of light collected. Background Technology

[0002] A method for producing EUV light comprises the step of converting a material into a plasma state having at least one element, such as xenon, lithium, or tin, having one or more emission lines in the EUV range, wherein the required plasma, sometimes referred to as a laser-produced plasma (“LPP”), can be produced by illuminating a target material having the required line-emitting element with a laser beam.

[0003] One specific LPP technique includes illuminating a target material droplet with one or more pre-pulse(s) followed by a main pulse.

[0004] From this perspective, CO2 lasers can offer specific advantages when the driving laser produces the "main" pulse in the LPP process. This may be particularly true for certain target materials, such as molten tin droplets. For example, one advantage may include the ability to produce relatively high conversion efficiency, such as the ratio of output EUV in-band power to driving laser input power.

[0005] Light source devices that generate EUV light generally have off-axis and on-axis structures, and are configured with a rotary-type target material feeder that stably induces the reflection angle of the optical system and the plasma reaction. Although light source devices supplying the rotary-type target material are widely applied in existing technologies because they stably induce the plasma reaction, they are designed as off-axis light output structures depending on the light output structure.

[0006] However, while the off-axis structure had advantages in the placement of the optical system, it had the problem of reduced light collection. Prior art literature

[0007] KR Registered Patent No. 10-1811306 KR Registered Patent No. 10-0875569 KR Registered Patent No. 10-2207666 KR Registered Patent No. 10-1484937 KR Published Patent No. 10-2011-0110578 KR Published Patent No. 10-2008-0041671 The problem to be solved

[0008] The present invention, aimed at solving the aforementioned problems, provides an EUV light source device capable of significantly improving the amount of light collected by improving the focusing structure while maintaining the existing target material supply system that requires a plasma reaction for EUV light generation.

[0009] In particular, the present invention aims to significantly improve the amount of light collected by configuring the optical system in an on-axis structure in an EUV light generating device having a rotating disk structure. means of solving the problem

[0010] The present invention, for achieving the above-mentioned purpose, comprises a rotating disk that is driven to rotate and confines the target material by centrifugal force to generate EUV light through a plasma reaction with the target material in an EUV light source device, wherein the rotating disk comprises a plurality of rotating disk ribs that support the rotating disk rim to transmit to a predetermined area of ​​the concentrated EUV light, which is concentrated through a collector mirror to receive the EUV light reflected therefrom, which is irradiated onto the target material by penetrating a beam output from a racer source through the center and concentrated to the same incident light axis.

[0011] In addition, the rotating disk rib is positioned between the rotating disk hub and the rotating disk rim, wherein the rotating disk rib is positioned such that only 5% to 20% of the light is blocked when transmitted, and the transmission area is larger than the blocking area in the concentration area of ​​the EUV light concentrated through the collector mirror.

[0012] In addition, the rotating disc rib has a supply channel formed therein for supplying a target material supplied from a target feeder that supplies a target material from the rotational center axis to the rotating disc rim.

[0013] In addition, the above-mentioned rotating disc rib is configured to include a rotating disc hub on the rotational center axis.

[0014] In addition, the rotary disc hub is characterized by having an upper flange and a lower flange formed on the upper side and the lower side, respectively, and having an upper coupling hole and a lower coupling hole formed on the upper flange and the lower flange, respectively, for coupling the rotary disc rib.

[0015] In addition, the rotating disk has a rim flange that extends from the rotating disk rim and is integrally formed so that a plurality of rotating disk ribs connected through the upper coupling hole and the lower coupling hole are coupled, and a rim coupling hole is formed in the rim flange.

[0016] In addition, the rotating disk hub has an equal number of rotating disk ribs coupled to the upper coupling hole and the lower coupling hole, respectively, and the coupled rotating disk ribs are fixed to the rim coupling hole.

[0017] In addition, the rotary disk hub is configured to further include a supply channel rib coupled to the rotary disk hub to provide a target material supplied from a droplet feeder to the rotary disk rim.

[0018] In addition, the supply Euro rib is characterized in that one side is coupled to the rotating disk hub and the other side is coupled to the rotating disk rim.

[0019] In addition, the rotary disc hub connects the upper flange and the lower flange to the rim flange through the upper disc rib and the lower disc rib.

[0020] In addition, the total number of the rotating disc ribs and the total number of the rim coupling holes are equal to the number of the upper coupling holes and the lower coupling holes, and the upper coupling holes and the rim coupling holes are connected through the upper disc ribs, and the lower coupling holes and the rim coupling holes are connected through the lower rim ribs, wherein the upper disc ribs and the lower rim ribs are arranged so as not to overlap each other at a certain distance.

[0021] In addition, the rim flange is formed in an 'L' shape on the inner edge of the lower disk (220b) of the rotating disk rim, and is characterized by having the rim coupling hole placed in a portion parallel to the lower disk.

[0022] In addition, the above-mentioned rotating disc rib is characterized by being a wire made of spring steel. Effects of the invention

[0023] The present invention, configured as described above, has the advantage of being able to provide an EUV light source device with an on-axis structure that has excellent light collection through the arrangement of a collector mirror and the structure of a rim configured on a rotating disk to implement an on-axis structure while maintaining a target material supply structure according to the plasma reaction of the EUV light source device. Brief explanation of the drawing

[0024] FIG. 1 is an overall configuration diagram of a rotating disk structure for an EUV light source device according to the present invention. FIG. 2 is a plan view showing one embodiment of a rotating disk structure for an EUV light source device according to the present invention. FIG. 3 is a plan view showing another embodiment of a rotating disk structure for an EUV light source device according to the present invention. FIG. 4 is a plan view showing another embodiment of a rotating disk structure for an EUV light source device according to the present invention. FIG. 5 is a cross-sectional view of a rotating disk according to FIG. 4, FIG. 6 is a plan view showing another embodiment of a rotating disk structure for an EUV light source device according to the present invention. FIG. 7 is an overall cross-sectional view showing an embodiment adopting a shield with a rotating disk structure for an EUV light source device according to the present invention. FIG. 8 is a plan view showing another embodiment of a rotary disk structure for an EUV light source device according to the present invention arranged off-axis. FIG. 9 is a cross-sectional view showing another embodiment of a rotating disk according to the present invention. FIG. 10 is a plan view of the rotating disk shown in FIG. 9, FIG. 11 is a plan view showing the state in which the disc ribs of a rotating disk according to the present invention are joined. Specific details for implementing the invention

[0025] Hereinafter, the structure of a rotating disk for an EUV light source device according to the present invention will be described in detail with reference to the attached drawings.

[0026] The rotating disk structure for an EUV light source device according to the present invention is a rotating disk that is driven to rotate to generate EUV light through a plasma reaction with a target material in an EUV light source device and confines the target material by centrifugal force, wherein the rotating disk comprises a plurality of rotating disk ribs that support a rotating disk rim to transmit to a predetermined area of ​​the concentrated EUV light, which is concentrated through a collector mirror for receiving the EUV light reflected therefrom, which is irradiated onto the target material by penetrating a beam output from a racer source through the center and concentrating it into the same incident light axis.

[0027] The main technical objective of the rotary disk structure for an EUV light source device according to the present invention is to provide an EUV light source device capable of significantly improving the amount of light collected compared to existing EUV light source devices by applying an on-axis focusing structure while applying a target material supply device of excellent structure configured to generate an EUV light source.

[0028] FIG. 1 is an overall configuration diagram of a rotating disk structure for an EUV light source device according to the present invention.

[0029] The EUV light source device according to the present invention is largely composed of a single laser source (100), a rotating disk (200) for confining a molten target material in a reaction space by centrifugal force for a plasma reaction, a heating means (500) for melting a target material (210) located in the reaction space of the rotating disk (200), and a collector mirror (300) that penetrates the center of a beam output from the laser source (100) to irradiate the target material and receives the reflected EUV light again to concentrate it along the same incident light axis. According to the technical gist of the present invention, the rotating disk (200) is configured to include a rotating disk rib (230) to have a transmission structure for a predetermined area of ​​the concentration region of the EUV light concentrated through the collector mirror (300).

[0030] In one embodiment according to the present invention, the laser source (100) may use a laser source having a pulse of 50 kHz to 200 kHz.

[0031] Additionally, the RPM of the rotating disk (200) can be determined according to the pulse repetition rate of the laser source, and the rotational speed of the rotating disk can be determined by the laser repetition rate.

[0032] Therefore, by designing and applying an on-axis light output structure so that a portion of the EUV light concentrated and output from the collector mirror (300) passes through (or is transmitted through) the rotating disk ribs (230) configured on the rotating disk (200), the problem of reduced light collection in the conventional off-axis structure can be efficiently resolved.

[0033] Here, the heating means (500) for heating the target material (210) preferably heats and melts the target material supplied to the inner surface (rotating disk rim) of the rotating disk while surrounding the outside of the rotating disk, and the heating means can be configured using various types of heaters such as a heater body, laser heating, induction method, ceramic method, etc.

[0034] Additionally, a separate heating device (not shown) may be configured in the collector mirror (300). Since target material fragment particles may be generated on the collector mirror and other optical systems or components configured within the EUV light source device in the chamber by the target material, thereby impairing optical properties, the heating device can be used to heat the collector mirror, optical systems, and components to clean the scattered fragments. Therefore, the heating device can be adopted as a cleaning means and can be configured within the chamber of the EUV light source device to remove fragment particles through the cleaning means.

[0035] Accordingly, in the present invention, a fragment removal function that can be removed through a heating device can be applied as a means to remove fragments generated by a target material in a rotating disk type EUV light source device.

[0036] FIG. 2 is a plan view showing an embodiment of a rotating disk of a rotating disk structure for an EUV light source device according to the present invention.

[0037] FIG. 2 is a planar view of the rotating disk (200). The rotating disk (200) has a circular structure and is driven to rotate through a driving means. At this time, the rotating disk (200) is configured to include a rotating disk rim (220) that accommodates a target substance and a plurality of rotating disk ribs (230) that support the rotating disk rim (220) from the rotation axis.

[0038] Accordingly, the rotating disc rib (230) is configured such that a plurality of rotating disc ribs (230) are applied so that the light collected from the collector mirror (300) can be transmitted when the EUV light is collected in an on-axis manner.

[0039] FIG. 3 is a plan view showing another embodiment of a rotating disk structure for an EUV light source device according to the present invention.

[0040] The above-mentioned rotating disc rib (230) is preferably configured to have a spoke structure so as to minimize interference when concentrated EUV light is transmitted.

[0041] The present invention has a technical feature in that it can excellently collect generated EUV light by using a rotating disk rib structure when concentrating light concentrated on a collector mirror in an on-axis manner, by configuring the structure of the rotating disk with a plurality of spoke structures.

[0042] FIG. 4 is a plan view showing another embodiment of a rotating disk structure for an EUV light source device according to the present invention.

[0043] In the present invention, various coupling structures between the rotating disk rim (220) and the rotating disk rib (230) can be proposed to ensure structural stability of the rotating disk (200), the rotating disk rim (220), and the rotating disk rib (230).

[0044] As described above, the rotating disc rib (230) is configured with a rotating disc hub (240) formed on a rotational center axis, and the rotating disc rib (230) can be assembled in a cross-type (tangent-type) structure between the rotating disc hub (240) and the rotating disc rim (220). Simply put, the cross-type is intended to increase rigidity so that multiple rotating disc ribs (spokes) cross and support each other, thereby safely withstanding external resistance caused by rotational force, such as twisting of the rotating disc rim (220) or impact from the side. Depending on the pattern, the number of intersecting rotating disc ribs can range from 1 to 4, and the rotating disc ribs (230) can be combined.

[0045] FIG. 5 is a cross-sectional view of a rotating disk according to FIG. 4. A rotating disk hub (240) configured on the central axis of the rotating disk is provided, and the rotating disk ribs (230) intersect to support the rotating disk rim (220). The rotating disk hub (240) is coupled to a driving means (400) to receive rotational force, and a target material located on the rotating disk rim (220) is confined by centrifugal force and reacts with a laser output from a laser source to generate EUV light through a plasma reaction.

[0046] FIG. 6 is a plan view showing another embodiment of a rotating disk structure for an EUV light source device according to the present invention.

[0047] In another embodiment according to the present invention, the rotating disc rib (230) is configured with a supply channel (231) having a predetermined width for supplying a target substance supplied from a target feeder that supplies a target substance from the rotating central axis to the rotating disc rim, and a droplet feeder (600) that supplies a target substance is located at the upper part of the central axis.

[0048] When a plasma reaction is generated for EUV light generation, the target material located on the rotating disk rim is reduced, and the reduced amount is continuously supplied from the droplet supplyer (600) to provide a stable plasma reaction.

[0049] The present invention, configured as described above, has the advantage of being able to provide an EUV light source device with an on-axis structure that has excellent light collection through the arrangement of a collector mirror and the structure of a rim configured on a rotating disk to implement an on-axis structure while maintaining a target material supply structure according to the plasma reaction of the EUV light source device.

[0050] Figure 7 shows that since target material fragment particles can be generated in the collector mirror and other optical systems or components that may be configured by the target material in the EUV light source device and impair optical properties, a shield (310, shield) can be placed to block said fragment particles.

[0051] The above shield (301) is positioned to surround the target material placed on the rotating disc rim so as to block fragment particles coming from the target material.

[0052] At this time, a single through hole (313) is provided in the shield so that a beam output from the laser source (100) is irradiated onto a target material and the collector mirror (300) receives the EUV light reflected therefrom. At this time, the single through hole is used as a passage hole through which the incident beam irradiated onto the target material and the reflected beam reflected from the target material pass.

[0053] If two holes are formed in the shield for the incident beam and the reflected beam, the two holes interfere with each other, causing a problem in the arrangement of the incident beam and the reflected beam, but if a single through hole is used, this problem can be solved.

[0054] Accordingly, in order to capture EUV light with a wide solid angle and simultaneously block generated fragments from the optical system, it is advantageous to apply a shield with a single hole.

[0055] Although the on-axis method has been described in this invention, the configuration of this invention can also be arranged in an off-axis manner as needed.

[0056] In other words, the focusing mirror that captures EUV light can have a spherical, aspherical, or elliptical shape and can capture light either on-axis or off-axis depending on the need.

[0057] Figure 8 illustrates an off-axis focusing structure in an EUV light source device, applying a target material supply device of excellent structure configured to generate an EUV light source.

[0058] As shown in FIG. 8, a single through hole (313) is provided in the shield to irradiate a target material with a beam output from the laser source (100) and to receive the EUV light reflected from it through an off-collector mirror (301). At this time, the single through hole is used as a passage hole through which the incident beam irradiated onto the target material and the reflected beam reflected from the target material pass.

[0059] The beam incident on the off-collector mirror (301) is focused for the EUV light source, and at this time, the off-center line (C2) of the off-collector mirror (301) is not parallel to the center line (C1) of the laser beam created from the laser source and incident on the target material, so they form an off-axis.

[0060] This arrangement can be advantageous as it avoids interference with peripheral equipment or rotating disks.

[0061] FIG. 9 is a cross-sectional view showing another embodiment of a rotating disk according to the present invention.

[0062] As described above, the rotating disk according to the present invention is configured with a rotating disk hub (240) having a spoke structure, and the rotating disk hub (240) has an upper flange (241) and a lower flange (242) configured on the upper and lower sides, respectively.

[0063] Additionally, as shown in drawing (a) below, the upper flange (241) has a plurality of upper coupling holes (242) formed along the circumference of the upper flange (241) for coupling a disk hub, and as shown in drawing (B), a plurality of lower coupling holes (244) are also formed in the lower flange (243).

[0064] At this time, the rim flange (221) is formed in an 'L' shape on the inner edge of the lower disk (220b) of the rotating disk rim (220), and the rim coupling hole (222) is positioned in a portion parallel to the lower disk (220b).

[0065] Thus, the rotating disk according to the present invention is configured by installing a single disk hub (240) and forming an upper disk rib (230-1) and a lower disk rib (230-2) through the upper flange (241) and the lower flange (243).

[0066] In addition, a rim flange (221) is formed that extends integrally with the rotating disc rim (220), and a rotating disc rib is connected to the rim flange (221).

[0067] Figure 10 is a plan view of the rotating disk shown in Figure 9.

[0068] FIG. 10 shows a plan view of a rotating disk, wherein a rim coupling hole (222) connected to the rotating disk rib is formed at the innermost end, and the rim coupling hole (222) is formed in a rim flange (221) that is integrally extended with the rotating disk rim.

[0069] The rim coupling hole (222) formed along the circumference of the rim flange (221) is formed to correspond to the number of upper coupling holes and lower coupling holes formed in the upper flange and lower flange, respectively, and in a preferred example, the number of rim coupling holes (222) is formed in multiples of two, so that the disc ribs coupled to the upper coupling holes and lower coupling holes are coupled to the rim coupling holes (222).

[0070] In addition, the total number of the rotating disc ribs and the total number of the rim coupling holes (222) are the same as the number of the upper coupling holes and the lower coupling holes, and the upper coupling holes and the rim coupling holes are connected through the upper disc ribs (230-1).

[0071] Here, the lower coupling hole and the rim coupling hole are connected through the lower risk rib (230-2), and the upper disc rib (230-1) and the lower risk rib (230-2) are configured to be arranged so as not to overlap each other at a certain distance.

[0072] Additionally, the rim flange (221) is formed in an 'L' shape on the inner edge of the lower disk (220b) of the rotating disk rim (220), and the rim coupling hole (222) is positioned in a portion parallel to the lower disk (220b).

[0073] FIG. 11 is a plan view showing the state in which the disc ribs of a rotating disk according to the present invention are combined.

[0074] FIG. 11 shows a plan view of the state in which the rotating disk hub (240) and the rotating disk (200) are combined, wherein disk ribs are connected from upper and lower coupling holes formed in the upper flange and lower flange, respectively, of the rotating disk hub (240) to the rim coupling hole (222). At this time, the upper disk rib (230-1) connected from the upper flange and the lower disk rib (230-2) connected from the lower flange start from the same point and are coupled to rim coupling holes at different positions.

[0075] In addition, a supply channel rib (232) is separately configured in the rotating disc rib. As previously mentioned, this configuration is for transferring the target material from the center to the rotating disc rim when supplying the target material from the rotational center axis. Thus, a structure is provided in which a supply channel rib (232) is separately configured in addition to the rotating disc rib to supply the target material. Although not specifically illustrated in the drawing, the supply channel rib (232) can receive the target material supplied to the droplet feeder (600) through a structure that is coupled to the rotating disc hub and communicates with the center.

[0076] As previously explained, this has the advantage of ensuring the structural stability of the rotating disk because it is joined in a cross-type manner, thereby securing the rigidity of the rotating disk and satisfying the strength requirements against deformation caused by twisting or rotational force.

[0077] Although preferred embodiments have been described and illustrated to illustrate the principles of the present invention, the present invention is not limited to the configuration and operation as depicted and described. Rather, those skilled in the art will understand that numerous changes and modifications to the present invention are possible without departing from the spirit and scope of the appended claims. Accordingly, all such appropriate changes and modifications and equivalents should be deemed to be within the scope of the present invention. Explanation of the symbols

[0078] 100 : Laser source 200 : Rotating disk 210: Target material 220 ; Rotating disc rim 220b : Lower disk 221 : Rim flange 222 : Rim coupling hole 230 : Rotating disc rib 231 : Supply Euros 232 : Supply Euro Liv 240 : Disk Hub 241 : Upper flange 242 : Upper coupling hole 243 : Lower flange 244 : Lower coupling hole 300 : Collector Mirror 400: Driving means 500 : Heating means 600 : Droplet feeder

Claims

Claim 1 A rotating disk that is driven to generate EUV light through a plasma reaction with a target material in an EUV light source device and confines the target material by centrifugal force, wherein the rotating disk comprises a plurality of rotating disk ribs that support the rotating disk rim so as to transmit to a predetermined area of ​​the concentration region of the EUV light concentrated through a collector mirror for receiving the EUV light reflected therefrom, which penetrates the center of the beam output from the racer source to irradiate the target material, and concentrates it to the same incident light axis, wherein a rotating disk hub is disposed on the rotational center axis of the rotating disk ribs, and the rotating disk ribs are disposed between the rotating disk hub and the rotating disk rim, and are disposed such that only 5% to 20% is blocked when light is transmitted, so as to have a transmission region larger than a blocking region in the concentration region of the EUV light concentrated through the collector mirror, and the rotating disk ribs have a supply channel formed therein for supplying the target material supplied from a target feeder that supplies the target material at the rotational center axis to the rotating disk rim, and is coupled to the rotating disk hub A rotating disk structure for an EUV light source device, comprising a supply channel rib, wherein one side of the supply channel rib is coupled to the rotating disk hub and the other side is coupled to the rotating disk rim, wherein the total number of rotating disk ribs and the total number of rim coupling holes are equal to the number of upper coupling holes and lower coupling holes, wherein the upper coupling holes and the rim coupling holes are connected through the upper disk ribs and the lower coupling holes and the rim coupling holes are connected through the lower disk ribs, wherein the upper disk ribs and the lower disk ribs are arranged at a certain distance from each other without overlapping, wherein the rim flange is formed in an 'L' shape on the inner edge of the lower disk of the rotating disk rim, and the rim coupling holes are arranged in a portion parallel to the lower disk. Claim 2 delete Claim 3 delete Claim 4 delete Claim 5 A rotating disk structure for an EUV light source device according to claim 1, wherein the rotating disk hub has an upper flange and a lower flange formed on the upper side and the lower side, respectively, and the upper flange and the lower flange each have an upper coupling hole and a lower coupling hole formed therein for coupling the rotating disk rib. Claim 6 In claim 5, the rotating disk structure for an EUV light source device is formed such that a rim flange extending from the rotating disk rim is integrally formed to allow a plurality of rotating disk ribs connected through the upper coupling hole and the lower coupling hole to be coupled, and a rim coupling hole is formed in the rim flange to allow the rotating disk ribs to be coupled. Claim 7 In claim 6, the rotary disk hub has an equal number of rotary disk ribs coupled to the upper coupling hole and the lower coupling hole, respectively, and the coupled rotary disk ribs are fixed to the rim coupling hole, forming a rotary disk structure for an EUV light source device. Claim 8 delete Claim 9 delete

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