Gas discharge lamp for extreme UV radiation
View Patent ↗The invention relates to a gas discharge lamp for EUV radiation with an anode ( 1 ) and a hollow cathode ( 2 ), wherein the hollow cathode ( 2 ) has at least two openings ( 3, 3 ′) and the anode ( 1 ) has a through hole ( 4 ), which is characterized in that the longitudinal axes ( 5, 5 ′) of the hollow cathode openings ( 3 ) have a common point of intersection S lying on the axis of symmetry ( 6 ) of the anode opening ( 4 ).
1. A gas discharge lamp for EUV radiation with an anode ( 1 ) and a hollow cathode ( 2 ), wherein the hollow cathode ( 2 ) has at least two openings ( 3 , 3 ′) and the anode ( 1 ) has a through opening ( 4 ), characterized in that the longitudinal axes ( 5 , 5 ′) of the hollow cathode openings ( 3 ) have a common point of intersection S which lies on the axis of symmetry ( 6 ) of the anode opening ( 4 ).
2. A gas discharge lamp as claimed in claim 1 , characterized in that the longitudinal axis ( 5 ) of each hollow cathode opening ( 3 ) is substantially perpendicular to the portion of the hollow cathode wall ( 7 ) situated opposite the respective hollow cathode opening ( 3 ).
3. A gas discharge lamp as claimed in claim 1 , characterized in that each hollow cathode opening ( 3 ) is associated with a separate hollow cathode space ( 8 ).
4. A gas discharge lamp as claimed in claim 1 , characterized in that a hollow cathode opening is formed as a blind hole.
5. A gas discharge lamp as claimed in claim 4 , characterized in that the hollow cathode opening ( 3 ) present on the axis of symmetry ( 6 ) is formed as a blind hole.
6. A gas discharge lamp as claimed in claim 1 , characterized in that the hollow cathode ( 2 ) has no opening ( 3 ) on the axis of symmetry ( 6 ) of the anode opening ( 4 ).
7. A gas discharge lamp as claimed in claim 1 , characterized in that the hollow cathode ( 2 ) has a through hole on the axis of symmetry ( 6 ) of the anode opening ( 4 ), the diameter of said through hole being smaller than the diameter of the other hollow cathode openings.
8. A gas discharge lamp as claimed in claim 1 , characterized in that the anode ( 1 ) has additional openings ( 4 ′, 4 ″) whose longitudinal axes ( 9 ′, 9 ″) each coincide with the longitudinal axis of a respective hollow cathode opening.
9. A gas discharge lamp as claimed in claim 8 , characterized in that, viewed from the point of intersection S, the spatial region behind the additional anode opening ( 4 ′, 4 ″) is closed.
10. A gas discharge lamp as claimed in claim 8 , characterized in that an additional anode opening ( 4 ′, 4 ″) is formed as a blind hole.
11. A gas discharge lamp as claimed in claim 8 , characterized in that the central through hole of the anode ( 4 ) is formed as a grid whose open regions are strip-shaped or in the form of a checkerboard.
12. A gas discharge lamp as claimed in claim 1 , characterized in that trigger devices ( 10 ) are provided for the hollow cathode space or spaces ( 8 ), preferably an additional electrode, a dielectric trigger, a pulsed high-frequency source, one or several glow discharge units, or a pulsed laser beam source.
13. A gas discharge lamp as claimed in claim 1 , characterized in that a double plasma arrangement with an auxiliary anode ( 17 ) is provided as the trigger device.