Abstract: A method of producing a radiating plasma with an increased flux stability and uniformity is disclosed. The method comprises the steps of generating a primary target by urging a liquid under pressure through a nozzle; directing an energy pre-pulse onto the primary target to generate a secondary target in the form of a gas or plasma cloud; allowing the thus formed secondary target to expand for a predetermined period of time; and directing a main energy pulse onto the secondary target when the predetermined period of time has elapsed in order to produce a plasma radiating X-ray or EUV radiation. The pre-pulse has a beam waist size that is larger, in at least one dimension, than the corresponding dimension of the primary target.

Abstract: A method of producing a radiating plasma with an increased flux stability and uniformity is disclosed. The method comprises the steps of generating a primary target by urging a liquid under pressure through a nozzle; directing an energy pre-pulse onto the primary target to generate a secondary target in the form of a gas or plasma cloud; allowing the thus formed secondary target to expand for a predetermined period of time; and directing a main energy pulse onto the secondary target when the predetermined period of time has elapsed in order to produce a plasma radiating X-ray or EUV radiation. The pre-pulse has a beam waist size that is larger, in at least one dimension, than the corresponding dimension of the primary target.

Abstract: In a method of generating X-ray or EUV radiation, a substance is urged through an outlet to generate a jet in a direction from the outlet, at least one energy beam is directed onto the jet, the energy beam interacting with the jet to generate the X-ray or EUV radiation, and the temperature of the outlet is controlled, such that the stability of the jet is improved. An apparatus is also disclosed.

Abstract: A method and an apparatus is designed to produce X-ray or EUV radiation for use in lithography, microscopy, materials science, or medical diagnostics. The radiation is produced by urging a substance through an outlet (6) to generate a microscopic jet (2) in a direction from the outlet (6), and by directing at least one energy beam (1′) onto the jet (2), wherein the energy beam (1′) interacts with the jet (2) to produce the X-ray or EUV radiation. The temperature of the outlet (6) is controlled to increase the directional stability of the jet (2). The thus-achieved directional stability of the jet (2) provides for reduced pulse-to-pulse fluctuations of the produced radiation, improved spatial stability of the radiation source, as well as high average power since the energy beam (1′) can be tightly focused on the jet (2), even at a comparatively large distance from the jet-generating outlet (6).

Abstract: A method for generating X- or EUV-radiation via laser plasma emission, in which at least one target (17) is generated in a chamber, and at least one pulsed laser beam (3) is focused on the target in the chamber. The target is generated in the form of a jet (17) of a liquid, and the laser beam (3) is focused on a spatially continuous portion of the jet (17). An apparatus for generating X- or EUV-radiation via laser plasma emission according to the method comprises a means for generating at least one laser beam (3), a chamber, a means (10) for generating at least one target (17) in the chamber, and a means (13) for focusing the laser beam (3) on the target (17) in the chamber (8). The target-generating means (10) is adapted to generate a jet (17) of a liquid. The focusing means (13) is adapted to focus the laser beam (3) on a spatially continuous portion of the jet (17).