Patent ID: 7239686
Filing Date: 2007-07-03
Classification: H05G

Abstract:
1. A method for producing X-ray or EUV radiation by emission from an energy beam produced plasma, comprising the steps of: generating a primary target by urging a liquid under pressure through a nozzle; directing a first energy pulse onto said primary target to generate a secondary target; allowing the secondary target to expand for a predetermined period of time; directing a second energy pulse onto said secondary target when said predetermined period of time has elapsed, the second energy pulse having an energy that is higher than the energy of the first energy pulse, in order to produce a plasma that emits the X-ray or EUV radiation; wherein the first energy pulse has a beam waist size at the primary target that is larger, in at least one dimension, than the corresponding size of said primary target, and wherein influence from primary target positional fluctuations, in said at least one dimension, on the stability of the radiation emitted by the plasma is reduced; and wherein the second energy pulse has a beam waist size that is smaller than the corresponding size of the secondary target at the time when the second energy pulse is directed onto said secondary target.