EUV COLLECTOR WITH ORIENTATION TO AVOID CONTAMINATION

摘要

The present disclosure relates to an extreme ultraviolet (EUV) radiation source having a collector mirror oriented to reduce contamination of fuel droplet debris. In some embodiments, the EUV radiation source has a fuel droplet generator that provides a plurality of fuel droplets to an EUV source vessel. A primary laser is configured to generate a primary laser beam directed towards the plurality of fuel droplets. The primary laser beam has a sufficient energy to ignite a plasma from the plurality of fuel droplets, which emits extreme ultraviolet radiation. A collector mirror, configured to focus the extreme ultraviolet radiation to an exit aperture of the EUV source vessel, which is oriented so that a normal vector extending outward from a vertex of the collector mirror intersects a direction of a gravitation force by an angle that is less than 90°.

主权项

1. An extreme ultraviolet (EUV) radiation source, comprising:
a fuel droplet generator configured to provide a plurality of fuel droplets to an EUV source vessel; a primary laser configured to generate a primary laser beam directed towards the plurality of fuel droplets, wherein the primary laser beam has a sufficient energy to ignite a plasma that emits extreme ultraviolet radiation from the plurality of fuel droplets; and a collector mirror configured to focus the extreme ultraviolet radiation to an exit aperture of the EUV source vessel, wherein the collector mirror is oriented so that a normal vector extending outward from a vertex of the collector mirror intersects a direction of a gravitation force by an angle that is less than 90°.