Filament for electron source
AssigneeHermes Microvision, Inc.
InventorJuying Dou
Life of this patent
Estimating the term…
Abstract
This invention relates to a filament for electron emission cathode which is employed in an electron microscope, a critical dimension examine tool, an electron beam lithograph machine, an electron beam tester and other electron beam related systems as an electron source. Embodiments of the present invention discloses method with which a Re (Rhenium) is used as heat source such that vibration issue of prior tungsten filament can be depressed.
Claims17
A filament for a Schottky electron emission source, comprising:
- a rhenium wire with a constant diameter equal to or larger than 0.006 inch and less than 0.01 inch.
A Schottky electron emission source, comprising:
- a base;
- two electrodes embedded into said base and distanced apart with each other;
- a rhenium wire with a constant diameter equal to or larger than 0.006 inch, being bended such that two ends thereof are welded to said two electrodes, central portion of the rhenium wire being convex to the two ends;
- an emitter mounting on the central portion of the rhenium wire;
- and
- a coating on a tip, wherein the coating is metal oxide.
A filament for a Schottky electron emission source, comprising:
- a tungsten wire with a constant diameter larger than 0.005 inch with a bended angle larger than 60 degree to depress vibration of the filament.
A Schottky electron emission source, comprising:
- a base;
- two electrodes embedded into said base and distanced apart with each other;
- a tungsten wire with a constant diameter equal to or larger than 0.005 inch, being bended at an angle larger than 60 degree to depress vibration of the filament such that two ends thereof are welded to said two electrodes, central portion of the tungsten wire being convex to the two ends;
- and
- an emitter mounting on the central portion of the tungsten wire.
Dependencies are inferred from the claim text.