Systems and methods are disclosed for protecting an EUV light source
plasma production chamber optical element surface from debris generated
by plasma formation. In one aspect of an embodiment of the present
invention, a shield is disclosed which comprises at least one hollow tube
positioned between the optical element and a plasma formation site. The
tube is oriented to capture debris while allowing light to pass through
the tube's lumen via reflection at relatively small angles of grazing
incidence. In another aspect of an embodiment of the present invention, a
shield is disclosed which is heated to a temperature sufficient to remove
one or more species of debris material that has deposited on the shield.
In yet another aspect of an embodiment of the present invention, a system
is disclosed which a shield is moved from a light source plasma chamber
to a cleaning chamber where the shield is cleaned.