CN-122003954-A - Anti-clogging droplet generator for EUV light sources

Abstract

A drop generator for an EUV light source includes a fluid chamber within a structure having a first fluid chamber end and a second fluid chamber end that are open or capable of receiving a fluid, a particulate filter within the fluid chamber dividing the fluid chamber into an upstream volume between an upstream surface of the particulate filter and the first fluid chamber end, a filter volume occupied by the filter, and a downstream volume downstream of the downstream surface of the filter, and a tube having a first opening positioned outside the fluid chamber, the tube extending from the first opening through the second fluid chamber end to a second opening within the downstream volume, the tube extending into the downstream volume more than 10% of a distance from the first opening to the second opening.

Inventors

• A B ldingg
• G. O. vaschenko
• A.I. Oshov

Assignees

• ASML荷兰有限公司

Dates

Publication Date

20260508

Application Date

20240828

Priority Date

20230905

Claims (20)

1. 1. A drop generator for an EUV light source, the drop generator comprising: A fluid chamber within the structure, the fluid chamber having a first fluid chamber end and a second fluid chamber end, the first fluid chamber end being open or capable of receiving a fluid; A particulate filter within the fluid chamber dividing the fluid chamber into an upstream volume between an upstream surface of the particulate filter and the first fluid chamber end, a filter volume occupied by the filter, and a downstream volume downstream of a downstream surface of the filter, and A tube having a first opening, the first opening being positioned outside the fluid chamber, the tube extending from the first opening through the second fluid chamber end to a second opening in the downstream volume, the tube extending into the downstream volume more than 10% of the distance from the first opening to the second opening.
2. 2. The drop generator of claim 1, wherein the tube extends into the downstream volume more than 20% of the distance from the first opening to the second opening.
3. 3. The drop generator of claim 1, wherein the tube extends into the downstream volume more than 30% of the distance from the first opening to the second opening.
4. 4. The drop generator of claim 1, wherein a distance from the second opening to any surface other than the surface of the tube is at least one millimeter (1 mm).
5. 5. The drop generator of claim 1, wherein a distance from the second opening to any surface other than the surface of the tube is at least 3 mm.
6. 6. The drop generator of claim 1, wherein the downstream volume comprises at least one dead volume.
7. 7. The drop generator of claim 6, wherein the downstream volume comprises at least two dead volumes.
8. 8. The drop generator of claim 1, wherein the downstream volume comprises a dead volume positioned below the fluid flow path in a direction of gravity when the drop generator is in operation.
9. 9. The drop generator of claim 8, wherein the downstream volume comprises a dead volume positioned above the fluid flow in a gravitational direction when the drop generator is in operation.
10. 10. The drop generator of claim 1, wherein the downstream volume comprises a dead volume positioned above the fluid flow in a gravitational direction when the drop generator is in operation.
11. 11. The drop generator of claim 1, wherein the second opening of the tube is oriented substantially perpendicular to gravity when the drop generator is in operation.
12. 12. The drop generator of claim 11, wherein the tube has at least one elbow positioned within the downstream volume.
13. 13. The drop generator of claim 1, wherein the tube has at least one elbow positioned within the downstream volume.
14. 14. The drop generator of claim 1, wherein the downstream volume comprises one or more respective dead volumes, and wherein one or more initial fill flow paths extend from the filter to the one or more respective dead volumes, and wherein the one or more initial fill flow paths do not encompass the second opening of the tube.
15. 15. The drop generator of claim 1, wherein the filter is positioned in-line between the first fluid chamber end and the second fluid chamber end.
16. 16. The drop generator of claim 1, wherein the filter is a cylindrical filter having a central opening extending at least partially axially through the filter.
17. 17. The drop generator of claim 16, wherein the second opening of the tube is positioned within the central opening of the filter.
18. 18. The drop generator of claim 1, wherein the filter is a cylindrical filter having a central opening extending axially through the filter.
19. 19. The drop generator of claim 18, wherein the second opening of the tube is positioned within the central opening of the filter.
20. 20. The drop generator of claim 18, wherein the tube extends completely through the central opening of the filter, the second opening being positioned outside the central opening of the filter.

Description

Anti-clogging droplet generator for EUV light sources Cross Reference to Related Applications The present application claims priority from U.S. application No. 63/580,549, entitled CLOG-RESISTANT DROPLET GENERATORS FOR EUV LIGHT SOURCES (anti-CLOG droplet generator for EUV light sources), filed on 5, 9, 2023, which is incorporated herein by reference in its entirety. Technical Field The present disclosure relates to an anti-clogging droplet generator for producing non-clogging or reduced clogging droplets in an Extreme Ultraviolet (EUV) light source. Background EUV light used for semiconductor lithography is supplied by a system called EUV light source. In EUV light sources, a droplet generator produces droplets that are irradiated with light from a light source (commonly referred to as a source laser). The droplets are formed of or comprise one or more materials capable of emitting EUV radiation in a plasma state. An EUV emitting plasma is generated from at least some of the material(s) of the irradiated droplets by energy from light from a source laser to irradiate the droplets. EUV light from the plasma is collected and transmitted to a lithographic apparatus for patterning in or on a semiconductor substrate. Due to the high cost of the semiconductor manufacturing process and the high value generated thereby, the normal operating time of EUV light sources is highly appreciated by users of EUV light sources. Disclosure of Invention In some general aspects, a drop generator for an EUV light source includes a fluid cavity within a structure having a first fluid cavity end and a second fluid cavity end that are open or capable of receiving a fluid, a particulate filter within the fluid cavity dividing the fluid cavity into an upstream volume between an upstream surface of the particulate filter and the first fluid cavity end, a filter volume occupied by the filter, and a downstream volume downstream of the downstream surface of the filter, and a tube having a first opening positioned outside the fluid cavity, the tube extending from the first opening through the second fluid cavity end to a second opening within the downstream volume, the tube extending into the downstream volume more than 10% of a distance from the first opening to the second opening. Implementations can include one or more of the following features. The tube may extend into the downstream volume more than 20% of the distance from the first opening to the second opening, or more than 30% of the distance from the first opening to the second opening. The distance from the second opening to any surface other than the surface of the tube may be at least one millimeter (1 mm), or at least 3 mm or more. The downstream volume may comprise at least one dead volume. The downstream volume may comprise at least two dead volumes. The downstream volume may comprise a dead volume positioned below the fluid flow path gravity when the drop generator is in operation. The downstream volume may comprise a dead volume positioned above the fluid flow in the direction of gravity when the drop generator is in operation. The downstream volume may comprise a dead volume positioned above the fluid flow in the direction of gravity when the drop generator is in operation. The tube may be oriented substantially perpendicular to gravity when the droplet generator is in operation. The tube may have at least one elbow positioned within the downstream volume. The downstream volume may include one or more respective dead volumes, and the one or more initial fill flow paths may extend from the filter to the one or more respective dead volumes, and the one or more initial fill flow paths may clear the second opening of the tube, so as not to encompass the second opening of the tube. The filter may be positioned in-line between the first fluid chamber end and the second fluid chamber end. The filter may be a cylindrical filter having a central opening extending at least partially axially through the filter. The second opening of the tube may be positioned within the central opening of the filter. The filter may be a cylindrical filter having a central opening extending axially through the filter. The tube may extend completely through the central opening of the filter, the second opening being positioned outside the central opening of the filter. When the droplet generator is in use, droplet material flowing within the fluid chamber may be rotated about 90 degrees or more to enter the second opening of the tube. When the droplet generator is in use, the droplet material flowing within the fluid chamber may be rotated about 180 degrees to enter the second opening of the tube. In an additional general aspect, a drop generator includes a filter having an interior volume configured to prevent particles in a fluid from passing through the filter to the interior volume, and a tube for transporting drops of the fluid through the drop generator, the tube having an upstream tube openin