Method for EUV power improvement with fuel droplet trajectory stabilization

摘要

The present disclosure relates to an extreme ultraviolet (EUV) radiation source that generates charged tin droplets having a trajectory controlled by an electromagnetic field, and an associated method. In some embodiments, the EUV radiation source has a laser that generates a laser beam. A charged fuel droplet generator provides a plurality of charged fuel droplets having a net electrical charge to an EUV source vessel. An electromagnetic field generator generates an electric field and/or a magnetic field. The net electrical charge of the charged fuel droplets causes the electric or magnetic field to generate a force on the charged fuel droplets that controls a trajectory of the charged fuel droplets to intersect the laser beam. By using the electric or magnetic field to control a trajectory of the charged fuel droplets, the EUV system is able to avoid focus issues between the laser beam and the charged fuel droplets.

主权项

1. An extreme ultraviolet (EUV) radiation source, comprising:
a charged fuel droplet generator configured to provide a plurality of charged fuel droplets having a net positive or negative electrical charge to an EUV source vessel wherein the charged fuel droplet generator comprises a fuel droplet generator configured to provide a plurality of uncharged fuel droplets to an EUV source vessel and an ion species injector configured to generate a beam of charged ion species that is incident upon the plurality of uncharged fuel droplets, wherein upon hitting the plurality of uncharged fuel droplets, the charged ion species attach to the plurality of uncharged fuel droplets to generate the plurality of charged fuel droplets; a laser configured to generate a laser beam having a sufficient energy to ignite a plasma from the charged fuel droplets, wherein the plasma emits extreme ultraviolet radiation; and an electromagnetic field generator configured to generate an electric field or a magnetic field that stabilizes a trajectory of the charged fuel droplets within the EUV source vessel, prior to ignition of the charged fuel droplets, along a path intersecting the laser beam; a control element configured to selectively adjust one or more characteristics of the ion species injector; and a measurement unit configured to measure a position of the charged fuel droplets and to provide a control signal to the control element to adjust a shape or size of the beam of charged ion species.