Abstract: A radiation source for an EUV lithography apparatus is disclosed. The radiation source comprises a chamber comprising a plasma formation region, a radiation collector arranged in the chamber and configured to collect radiation emitted at the plasma formation region and to direct the collected radiation towards an intermediate focus region, and a radiation conduit disposed between the radiation collector and the intermediate focus region. The radiation conduit comprises at least one outlet on an inner surface of a wall of the radiation conduit for directing a protective gas flow, and at least one guide portion extending from the inner surface of the wall of the radiation conduit and configured to redirect the protective gas flow. Also disclosed is a method of reducing debris and/or vapor deposition in the radiation conduit by providing a protective gas flow to the at least one outlet of the radiation conduit.

Abstract: A radiation collector comprising a first collector segment comprising a plurality of grazing incidence reflector shells configured to direct radiation to converge in a first location at a distance from the radiation collector, a second collector segment comprising a plurality of grazing incidence reflector shells configured to direct radiation to converge in a second location at said distance from the radiation collector, wherein the first location and the second location are separated from one another.

Abstract: A radiation source having a fuel stream generator (110) that generates and directs a fuel stream (102) along a trajectory towards a plasma formation location (104). A pre-pulse laser radiation assembly directs a first beam of laser radiation (100) at the fuel stream at the plasma formation location to generate a modified fuel target (106). A main pulse laser radiation assembly directs a second beam of laser radiation (108) at the modified fuel target at the plasma formation location to generate a radiation generating plasma (117). A collector (122) collects the radiation and directs it along an optical axis (105) of the radiation source. The first beam of laser radiation being directed toward the fuel stream substantially along the optical axis.

Abstract: A mount configured to mount an optical element in a module for a lithographic apparatus. The mount includes a plurality of resilient members constructed and arranged to circumferentially support the optical element. Each resilient member includes a plurality of resilient subsections that are configured to engage the optical element around a perimeter thereof. Each resilient subsection is configured to flex independent of another resilient subsection.

Abstract: A radiation collector (141) comprising a plurality of reflective surfaces (400-405), wherein each of the plurality of reflective surfaces is coincident with part of one of a plurality of ellipsoids (40-45), wherein the plurality of ellipsoids have in common a first focus (12) and a second focus (16), each of the plurality of reflective surfaces coincident with a different one of the plurality of ellipsoids, wherein the plurality of reflective surfaces are configured to receive radiation originating from the first focus (12) and reflect the radiation to the second focus (16). An apparatus (820) shown in FIG.

Abstract: A radiation collector comprising a first collector segment comprising a plurality of grazing incidence reflector shells configured to direct radiation to converge in a first location at a distance from the radiation collector, a second collector segment comprising a plurality of grazing incidence reflector shells configured to direct radiation to converge in a second location at said distance from the radiation collector, wherein the first location and the second location are separated from one another.

Abstract: A radiation source having a fuel stream generator (110) that generates and directs a fuel stream (102) along a trajectory towards a plasma formation location (104). A pre-pulse laser radiation assembly directs a first beam of laser radiation (100) at the fuel stream at the plasma formation location to generate a modified fuel target (106). A main pulse laser radiation assembly directs a second beam of laser radiation (108) at the modified fuel target at the plasma formation location to generate a radiation generating plasma (117). A collector (122) collects the radiation and directs it along an optical axis (105) of the radiation source. The first beam of laser radiation being directed toward the fuel stream substantially along the optical axis.

Abstract: A mount configured to mount an optical element in a module for a lithographic apparatus. The mount includes a plurality of resilient members constructed and arranged to circumferentially support the optical element. Each resilient member includes a plurality of resilient subsections that are configured to engage the optical element around a perimeter thereof Each resilient subsection is configured to flex independent of another resilient subsection.