Abstract:
A radiation source for a lithographic apparatus, in particular a laser-produced plasma source includes a fan unit surrounding but not obstructing the collected radiation beam that is operated to generate a flow in a buffer gas away from the optical axis. The fan unit can comprise a plurality of flat or curved blades generally parallel to the optical axis and driven to rotate about the optical axis.
Abstract:
A lithographic apparatus comprises a first object holder (WT) and a second object holder. The first object holder is arranged for holding an object (W) at a holder-facing surface. The object has the holder-facing surface. The second object holder is arranged for holding the object at the holder-facing surface. The lithographic apparatus is arranged to deform a contaminating particle (50) at the holder-facing surface more when the object is held at the second object holder than when the object is held at the first object holder.
Abstract:
A radiation source generates extreme ultraviolet radiation for a lithographic apparatus as a chamber that is provided with a low pressure hydrogen environment. A trace amount of a protective compound, e.g., H 2 O, H 2 O 2 , O 2 , NH 3 or NO x , is provided to the chamber to assist in maintaining a protective oxide film on metal, e.g., titanium, components in the chamber.