Patent ID: 7368742

Claim:
An arrangement for metering target material for the generation of EUV radiation, comprising: a target generator being arranged for providing target material along a given target path; an energy beam for generating a radiation-emitting plasma being directed to the target path; said target generator having an injection device which contains a nozzle chamber with nozzle and which is connected with a reservoir; means being provided for a defined, temporary pressure increase in the nozzle chamber in order to introduce an individual target into the interaction chamber at the interaction point exclusively when required for the generation of plasma; and means being arranged in the nozzle for adjusting an equilibrium pressure in order to compensate for a pressure drop at the nozzle of the injection device resulting from the pressure difference between the vacuum pressure in the interaction chamber and the pressure exerted on the target material in the reservoir; wherein the adjusted equilibrium pressure prevents the escape of target material as long as there is no temporary pressure increase in the nozzle chamber.