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US 9,544,986 B2Granted
Extreme ultraviolet source with magnetic cusp plasma control
AssigneePlex LLC
InventorMalcolm W. McGeoch
Life of this patent
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Abstract
A laser-produced plasma extreme ultraviolet source has a buffer gas to slow ions down and thermalize them in a low temperature plasma. The plasma is initially trapped in a symmetrical cusp magnetic field configuration with a low magnetic field barrier to radial motion. Plasma overflows in a full range of radial directions and is conducted within a cone-shaped sheet to an annular beam dump.
Claims8
An extreme ultraviolet light source comprising:
- a chamber;
- a source of droplet targets;
- one or more lasers focused onto the droplets in an interaction region;
- a flowing buffer gas;
- a reflective collector element to redirect extreme ultraviolet light to a point on the collector optical axis which is an exit port of the chamber;
- an annular beam dump disposed around the collector optical axis;
- a magnetic field provided by two sets of opposed magnetic field generators that create an asymmetrical magnetic cusp with magnetic well conforming to the inside shape of the collector, wherein the laser-plasma interaction takes place at or near the zero magnetic field point of the cusp and heat and target material particles are removed to a beam dump via magnetically guided plasma flow in a cone-shaped plasma sheet with cone axis parallel to the optical axis.
4 more elements
Dependencies are inferred from the claim text.