Systems and methods for target material delivery protection in a laser produced plasma EUV light source
View Patent ↗A device is disclosed herein which may comprise a chamber, a source providing a stream of target material droplets delivering target material to an irradiation region in the chamber along a path between a target material release point and the irradiation region, a gas flow in the chamber, at least a portion of the gas flowing in a direction toward the droplet stream, a system producing a laser beam irradiating droplets at the irradiation region to generate a plasma producing EUV radiation, and a shroud positioned along a portion of said stream, said shroud having a first shroud portion shielding droplets from said flow and an opposed open portion.
1. A device comprising:
a chamber;
a source providing a stream of target material delivering target material to an irradiation region in the chamber along a path between a target material release point and the irradiation region;
a gas flow in the chamber, at least a portion of the gas flowing in a direction toward the stream;
a system producing a laser beam irradiating target material at the irradiation region to generate a plasma producing EUV radiation; and
a shroud positioned along a portion of said stream, said shroud having a first shroud portion shielding the stream from said flow and an opposed open portion.
2. A device as recited in claim 1 wherein said shroud has a partial ring-shaped cross-section in a plane normal to said path.
3. A device as recited in claim 2 wherein said ring has at least one flat surface.
4. A device as recited in claim 1 wherein the shroud is elongated in a direction parallel to said path.
5. A device as recited in claim 1 wherein said shroud comprises a tube formed with at least one hole.
6. A device as recited in claim 1 further comprising a droplet catch tube positioned along said stream between said shroud and said target material release point.
7. A device as recited in claim 6 wherein said path is non-vertical and said droplet catch tube is a shield protecting the reflective optic from target material straying from the non-vertical path.
8. A device comprising:
a chamber;
a source providing a stream of target material droplets delivering target material to an irradiation region in the chamber along a path between the irradiation region and a target material release point;
a gas flow in the chamber;
a laser producing a beam irradiating droplets at the irradiation region to generate a plasma producing EUV radiation; and
a shroud positioned along a portion of said stream, said shroud partially enveloping said stream in a plane normal to said path to increase droplet positional stability.
9. A device as recited in claim 8 wherein said shroud has a partial ring-shaped cross-section in a plane normal to said path.
10. A device as recited in claim 9 wherein said ring has at least one flat surface.
11. A device as recited in claim 8 wherein the shroud is elongated in a direction parallel to said path.
12. A device as recited in claim 8 wherein said shroud comprises a tube formed with at least one hole.
13. A device as recited in claim 8 further comprising a droplet catch tube positioned along said stream between said shroud and said target material release point.
14. A device as recited in claim 13 wherein said path is non-vertical and said droplet catch tube is a shield protecting the reflective optic from target material straying from the non-vertical path.
15. A method comprising the steps of:
providing a stream of target material droplets delivering target material to an irradiation region in a chamber along a path between a target material release point and the irradiation region;
flowing a gas in a direction toward the droplet stream;
irradiating droplets with a laser beam at the irradiation region to generate a plasma producing EUV radiation; and
positioning a shroud along a portion of said stream, said shroud having a first shroud portion shielding droplets from said flow and an opposed open portion.
16. A method as recited in claim 15 wherein said flowing and irradiating steps occur simultaneously.
17. A method as recited in claim 15 wherein said shroud has a partial ring shaped cross section in a plane normal to said path.
18. A method as recited in claim 15 wherein said ring has at least one flat surface.
19. A method as recited in claim 15 wherein the shroud is elongated in a direction parallel to said path.
20. A method as recited in claim 15 further comprising the step of positioning a droplet catch tube along said stream between said shroud and said target material release point.
21. A device as recited in claim 1 wherein at least a portion of said stream is a droplet stream.