Light source device and exposure equipment using the same
View Patent ↗A light source device capable of extending the life of a collector mirror and reducing running cost by protecting the collector mirror from debris that is considered harmful to a mirror coating while securing the collection solid angle and collection rate of EUV light. The light source device includes a target supply unit for supplying a material to become the target; a laser unit for generating plasma by applying a laser beam to the target; a collection optical system for collecting the extreme ultra violet light radiating from the plasma and emitting the extreme ultra violet light; and magnetic field generating unit for generating a magnetic field within the collection optical system when supplied with current so as to trap charged particles radiating from the plasma.
1. A light source device for generating extreme ultra violet light by applying a laser beam to a target, said device comprising:
a target supply unit for supplying a material to become said target;
a laser unit for generating plasma by applying a laser beam to said target;
a collection optical system for collecting the extreme ultra violet light radiating from said plasma and emitting the extreme ultra violet light; and
magnetic field generating means for generating a magnetic field within said collection optical system when supplied with current so as to trap charged particles radiating from said plasma.
2. The light source device according to claim 1 , wherein said magnetic field generating means includes a pair of mirror coils that sandwich said collection optical system.
3. The light source device according to claim 1 , wherein said magnetic field generating means includes a baseball coil that wraps around said collection optical system.
4. The light source device according to claim 1 , further comprising:
current supply means for supplying current to said magnetic field generating means so as to generate a steady magnetic field within said collection optical system.
5. The light source device according to claim 1 , further comprising:
current supply means for supplying current to said magnetic field generating means; and
timing control means for controlling said current supply means to generate a pulse magnetic field within said collection optical system.
6. The light source device according to claim 1 , further comprising:
an electrode for generating an electric field in a periphery of said collection optical system; and
voltage supply means for applying a positive potential to said electrode.
7. The light source device according to claim 6 , further comprising:
current supply means for supplying current to said magnetic field generating means; and
timing control means for controlling said current supply means to generate a pulse magnetic field within said collection optical system and controlling said voltage supply means to generate a pulse electric field in the periphery of said collection optical system.
8. The light source device according to claim 1 , further comprising:
charging means for ionizing and/or charging neutral particles by applying ultraviolet light to the neutral particles radiating from said plasma.
9. Exposure equipment for exposing an object to light by using extreme ultra violet light generated by applying a laser beam to a target, said equipment comprising:
a target supply unit for supplying a material to become said target;
a laser unit for generating plasma by applying a laser beam to said target;
a collection optical system for collecting the extreme ultra violet light radiating from said plasma and emitting the extreme ultra violet light;
magnetic field generating means for generating a magnetic field within said collection optical system when supplied with current so as to trap charged particles radiating from said plasma;
an illuminating optical system for collecting the extreme ultra violet light emitted from said collection optical system onto a mask by using plural mirrors; and
a projection optical system for exposing said object to light by using the extreme ultra violet light reflected from said mask.
10. The exposure equipment according to claim 9 , wherein said magnetic field generating means includes a pair of mirror coils that sandwich said collection optical system.
11. The exposure equipment according to claim 9 , wherein said magnetic field generating means includes a baseball coil that wraps around said collection optical system.
12. The exposure equipment according to claim 9 , further comprising current supply means for supplying current to said magnetic field generating means so as to generate a steady magnetic field within said collection optical system.
13. The exposure equipment according to claim 9 , further comprising:
current supply means for supplying current to said magnetic field generating means; and
timing control means for controlling said current supply means to generate a pulse magnetic field within said collection optical system.
14. The exposure equipment according to claim 9 , further comprising:
an electrode for generating an electric field in a periphery of said collection optical system; and
voltage supply means for applying a positive potential to said electrode.
15. The exposure equipment according to claim 14 , further comprising:
current supply means for supplying current to said magnetic field generating means; and
timing control means for controlling said current supply means to generate a pulse magnetic field within said collection optical system and controlling said voltage supply means to generate a pulse electric field in the periphery of said collection optical system.
16. The exposure equipment according to claim 9 , further comprising:
charging means for ionizing and/or charging neutral particles by applying ultraviolet light to the neutral particles radiating from said plasma.