EUV light source
View Patent ↗An apparatus and method for EUV light production is disclosed which may comprise a laser produced plasma (“LPP”) extreme ultraviolet (“EUV”) light source control system comprising a target delivery system adapted to deliver moving plasma initiation targets and an EUV light collection optic having a ibeus defining a desired plasma initiation site, comprising; a target tracking and feedback system comprising: at least one imaging device providing as an output an image of a target stream track, wherein the target stream track results from the imaging speed of the camera being too slow to image individual plasma formation targets forming the target stream imaged as the target stream track; a stream track error detector detecting an error in the position of the target stream track in at least one axis genemily perpendicular to the target stream track from a desired stream truck intersecting the desired plasma initiation site.
1. A laser produced plasma (“LPP”) extreme ultraviolet (“EUV”) light source having a drive laser producing a drive laser output pulse beam and a drive laser output pulse beam directing system and an EUV light collector having a collector focus, comprising:
a beam focusing system intermediate the beam directing system and the collector focus, operative to focus the output laser pulse beam to a selected position in the vicinity of the collector focus defining a selected plasma initiation site comprising a focusing lens and a reflective focusing element intermediate the focusing lens and the collector focus and having a focusing lens focal point intermediate the focusing lens and the reflective focusing element; and the reflective focusing element focusing the beam at the selected position.
2. The apparatus of claim 1 further comprising:
the beam focusing system being moveable and movement of the beam focusing system being operative to locate the focus of the beam focusing system at the selected position.
3. The apparatus of claim 2 further comprising:
a aperture in the vicinity of the focus of the focusing lens, intermediate the focusing lens and the reflective element operative to block plasma initiation debris from reaching the focusing lens.
4. The apparatus of claim 1 further comprising:
the beam focusing system being moveable and movement of the beam focusing system being operative to locate the focus of the beam focusing system at the selected position.
5. The apparatus of claim 4 further comprising:
at least one of the focusing lens and the reflective focusing element being moveable and the relative movement between the focusing lens and the reflective focusing element being operative at least in part to locate the focus of the beam at the selected position.
6. The apparatus of claim 5 further comprising:
the reflective focusing element comprises a grazing angle of incidence reflecting element.
7. The apparatus of claim 5 further comprising:
the reflective focusing element comprises a normal angle of incidence reflective element.
8. The apparatus of claim 4 further comprising:
the reflective focusing element comprises a grazing angle of incidence reflecting element.
9. The apparatus of claim 4 further comprising:
the reflective focusing element comprises a normal angle of incidence reflective element.
10. The apparatus of claim 4 further comprising:
the reflective focusing element comprises a normal angle of incidence reflective element.
11. The apparatus of claim 1 further comprising:
at least one of the focusing lens and the reflective focusing element being moveable and the relative movement between the focusing lens and the reflective focusing element being operative at least in part to locate the focus of the beam at the selected position.
12. The apparatus of claim 11 further comprising:
the reflective focusing element comprises a grazing angle of incidence reflecting element.
13. The apparatus of claim 1 further comprising:
the reflective focusing element comprises a grazing angle of incidence reflecting element.
14. The apparatus of claim 1 further comprising:
the reflective focusing element comprises a normal angle of incidence reflective element.
15. A method for producing laser produced plasma (“LPP”) extreme ultraviolet (“EUV”) light comprising utilizing a drive laser producing a drive laser output pulse beam and a drive laser output pulse beam directing system and an EUV light collector having a focus, comprising:
focusing the beam intermediate the beam directing system and the collector focus, utilizing a focusing optic to focus the output laser pulse beam to a selected position in the vicinity of the focus.
16. A laser produced plasma (“LPP”) extreme ultraviolet (“EUV”) light source having a drive laser producing a drive laser output pulse beam and an EUV light collector having a collector focus, comprising:
a beam focusing system intermediate the drive laser and the collector focus, operative to focus the output laser pulse beam to a selected position in the vicinity of the collector focus defining a selected plasma initiation site, comprising a focusing lens and a reflective focusing element intermediate the focusing lens and the collector focus and having a focusing lens focal point intermediate the focusing lens and the reflective focusing element;
and the reflective focusing element focusing the beam at the selected position.
17. The apparatus of claim 16 further comprising: the beam focusing system being moveable and movement of the beam focusing system being operative to locate the focus of the beam focusing system at the selected position.
18. The apparatus of claim 17 further comprising: at least one of the focusing lens and the reflective focusing element being moveable and the relative movement between the focusing lens and the reflective focusing element being operative at least in part to locate the focus of the beam at the selected position.
19. The apparatus of claim 18 further comprising: the reflective focusing element comprises a normal angle of incidence reflective element.
20. The apparatus of claim 18 further comprising: a aperture in the vicinity of the focus of the focusing lens, intermediate the focusing lens and the reflective element operative to block plasma initiation debris from reaching the focusing lens.
21. The apparatus of claim 20 further comprising: the reflective focusing element comprises a grazing angle of incidence reflecting element.
22. The apparatus of claim 17 further comprising: a aperture in the vicinity of the focus of the focusing lens, intermediate the focusing lens and the reflective element operative to block plasma initiation debris from reaching the focusing lens.
23. The apparatus of claim 22 further comprising: the reflective focusing element comprises a grazing angle of incidence reflecting element.
24. The apparatus of claim 17 further comprising: the reflective focusing element comprises a normal angle of incidence reflective element.
25. The apparatus of claim 16 further comprising: at least one of the focusing lens and the reflective focusing element being moveable and the relative movement between the focusing lens and the reflective focusing element being operative at least in part to locate the focus of the beam at the selected position.
26. The apparatus of claim 25 further comprising: the reflective focusing element comprises a grazing angle of incidence reflecting element.
27. The apparatus of claim 25 further comprising: the reflective focusing element comprises a normal angle of incidence reflective element.
28. The apparatus of claim 25 further comprising: a aperture in the vicinity of the focus of the focusing lens, intermediate the focusing lens and the reflective element operative to block plasma initiation debris from reaching the focusing lens.
29. The apparatus of claim 16 further comprising: the reflective focusing element comprises a grazing angle of incidence reflecting element.
30. The apparatus of claim 16 further comprising: the reflective focusing element comprises a normal angle of incidence reflective element.
31. The apparatus of claim 16 further comprising: a aperture in the vicinity of the focus of the focusing lens, intermediate the focusing lens and the reflective element operative to block plasma initiation debris from reaching the focusing lens.
32. A method for producing laser produced plasma (“LPP”) extreme ultraviolet (“EUV”) light comprising utilizing a drive laser producing a drive laser output pulse beam and an EUV light collector having a focus, comprising: focusing the beam to a focal plane intermediate the laser and the collector focus, and utilizing a focusing element intermediate the focal plane of the beam and the collector focus to focus the output laser pulse beam to a selected position in the vicinity of the collector focus.