Patent ID: 8143606

Claim:
An extreme ultra violet light source device of a laser produced plasma type, the device comprising: a target nozzle that supplies a target material; a chamber in which extreme ultra violet light is generated by irradiating the target material supplied from said target nozzle with a laser beam emitted from a laser unit to produce plasma; collector optics that collect the extreme ultra violet light radiated from the plasma; a target recovery unit located at a position facing said target nozzle, for recovering the target material that has not been irradiated with the laser beam; a magnetic field forming unit for forming an asymmetric magnetic field in a position where the target material is irradiated with the laser beam, the magnetic field being asymmetrical with respect to a plane perpendicular to a central axis of lines of magnetic flux; an ion ejection port provided to said chamber to receive ions moving along a direction parallel with the magnetic flux formed by said magnetic field forming unit; and an electric field forming unit including plural electrodes and a power supply unit, for forming an electric field in the asymmetric magnetic field formed by said magnetic field forming unit, wherein said magnetic field forming unit includes a plurality of coils that generate magnetic fields when supplied with electric current, said coils being arranged in parallel with each other such that central axes of said coils are substantially common with each other, and wherein said target nozzle is located to inject the target material in a direction which intersects with magnetic flux lines of the asymmetric magnetic field formed by said magnetic field forming unit.