Extreme ultraviolet light source

摘要

Techniques are described that enhance power from an extreme ultraviolet light source with feedback from a target material that has been modified prior to entering a target location into a spatially-extended target distribution or expanded target. The feedback from the spatially-extended target distribution provides a nonresonant optical cavity because the geometry of the path over which feedback occurs, such as the round-trip length and direction, can change in time, or the shape of the spatially-extended target distribution may not provide a smooth enough reflectance. However, it may be possible that the feedback from the spatially-extended target distribution provides a resonant and coherent optical cavity if the geometric and physical constraints noted above are overcome. In any case, the feedback can be generated using spontaneously emitted light that is produced from a non-oscillator gain medium.

主权项

1. A method comprising:
releasing target material from an initial location toward a target region, the target material comprising a material that emits extreme ultraviolet (EUV) light when converted to plasma; interacting a pulse of light with the target material while the target material is between the initial location and the target region, the interaction producing a spatially extended target distribution having a larger extent in a direction that is different from a direction of propagation of the pulse of light than the target material; positioning an optic to establish a beam path that intersects the target region; coupling a gain medium to the beam path, the gain medium spontaneously emitting at least one photon onto the beam path; and interacting photons emitted from the gain medium with the spatially extended target distribution, when the spatially extended target distribution is in the target region, to produce an amplified light beam that converts at least some of the target material in the spatially extended target distribution to plasma that generates EUV light.