Radiation Source for an EUV Optical Lithographic Apparatus, and Lithographic Apparatus Comprising such a Radiation Source

摘要

A radiation source generates extreme ultraviolet radiation. The radiation source comprises a plasma formation site located at a position in which a fuel will be contacted by a beam of radiation to form a plasma. A receiving structure is provided to trap debris particles on its surface that are generated with the formation of the plasma. The receiving structure has a rod-shaped heater element for heating the receiving surface, the device preventing large droplets of fuel from forming on the receiving surface. Instead, the trapped fuel is melted off the receiving surface.

主权项

1. A radiation source apparatus configured to generate a beam of radiation by excitation of a fuel into a plasma, said apparatus comprising:
a plasma formation site located at a position in which a fuel will be contacted by a laser beam of radiation to form a plasma; a receiving structure having a receiving surface for capturing fuel debris that is generated with the formation of the plasma; and a heating arrangement for heating one or more receiving surfaces of said receiving structure to a temperature sufficient to liquefy said fuel debris such that it can be made to flow along the surface to another part of the apparatus, said arrangement comprising a heater element for heating of said receiving surface, wherein a portion of the heater element has an adjustable length for providing heating control of the heater element.