Extreme ultra violet light source device
View Patent ↗An extreme ultra violet light source device of a laser produced plasma type, in which charged particles such as ions emitted from plasma can be efficiently ejected. The extreme ultra violet light source device includes: a target nozzle that supplies a target material; a laser oscillator that applies a laser beam to the target material supplied from the target nozzle to generate plasma; collector optics that collects extreme ultra violet light radiated from the plasma; and a magnetic field forming unit that forms an asymmetric magnetic field in a position where the laser beam is applied to the target material.
1. 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.
2. The extreme ultra violet light source device according to claim 1 , wherein said coils have different shapes from each other and/or different sizes from each other.
3. The extreme ultra violet light source device according to claim 1 , wherein said magnetic field forming unit further includes a plurality of magnetic cores having different shapes from each other and/or different sizes from each other, said magnetic cores being inserted into central openings of said coils, respectively.
4. The extreme ultra violet light source device according to claim 1 , wherein said coils include superconducting coils.
5. The extreme ultra violet light source device according to claim 1 , wherein said magnetic field forming unit supplies electric currents having different magnitudes from each other to said coils, respectively.
6. The extreme ultra violet light source device according to claim 1 , wherein said magnetic field forming unit supplies electric currents in different directions from each other to said coils, respectively.
7. The extreme ultra violet light source device according to claim 1 , wherein said coils are formed of winding wires, respectively, and wherein numbers of turns and/or diameters of turns of said winding wires in said coils are different from each other.
8. The extreme ultra violet light source device according to claim 1 , wherein said magnetic field forming unit further includes a shielding guide for shielding a part of the magnetic fields formed by said coils.
9. The extreme ultra violet light source device according to claim 1 , wherein said ion ejection port is provided in a direction from a higher magnetic flux density to a lower magnetic flux density of the asymmetric magnetic field formed by said magnetic field forming unit.
10. The extreme ultra violet light source device according to claim 1 , wherein a central axis of said target nozzle is oriented in a direction perpendicular to a central axis of lines of magnetic flux of the asymmetric magnetic field formed by said magnetic field forming unit.
11. 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 laser beam is applied to 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 permanent magnets that generate magnetic fields having different sizes from each other, respectively, said permanent magnets being arranged in parallel with each other such that central axes of said permanent magnets 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.
12. The extreme ultra violet light source device according to claim 11 , wherein said magnetic field forming unit further includes a shielding guide for shielding a part of the magnetic field formed by said permanent magnets.
13. The extreme ultra violet light source device according to claim 12 , wherein said shielding guide contains one of iron, cobalt, nickel and ferrite.
14. The extreme ultra violet light source device according to claim 11 , wherein said ion ejection port is provided in a direction from a higher magnetic flux density to a lower magnetic flux density of the asymmetric magnetic field formed by said magnetic field forming unit.
15. The extreme ultra violet light source device according to claim 11 , wherein a central axis of said target nozzle is oriented in a direction perpendicular to a central axis of lines of magnetic flux of the asymmetric magnetic field formed by said magnetic field forming unit.