Silicon carbide based triode electron emitter and producing an electron beam with same
OwnerHenri Joseph Lezec, Dhruv Fomrainventors
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Abstract
A silicon carbide based triode electron emitter includes a silicon carbide substrate having a top surface, an emitter tip formed integrally with and extending upward from the top surface of the silicon carbide substrate, an insulator layer on the top surface of the silicon carbide substrate and the emitter tip, and an extractor electrode with an extraction aperture. A lower surface of the extractor electrode is closer to an apex of the emitter tip than the top surface of the silicon carbide substrate. This emitter operates at a lower operating voltage, higher current density, and extended lifetime compared to conventional cold field emitters.
Claims20
A silicon carbide based triode electron emitter (10) comprising:
- a silicon carbide substrate (12) having a top surface (14);
- an emitter tip (16) formed integrally with and extending upward from the top surface (14) of the silicon carbide substrate (12), the emitter tip (16) having a radius of curvature less than 20 nanometers;
- an insulator layer (18) on the top surface (14) of the silicon carbide substrate (12) and the emitter tip (16), the insulator layer (18) having a predetermined thickness;
- an extractor electrode (20) on the insulator layer (18), the extractor electrode (20) comprising an extraction aperture (22) centered over the emitter tip (16);
- wherein a lower surface (24) of the extractor electrode (20) is closer to an apex (26) of the emitter tip (16) than the top surface (14) of the silicon carbide substrate (12).
A process for fabricating a silicon carbide based triode electron emitter (10), the process comprising:
- providing a silicon carbide substrate (12) comprising a top surface (14);
- forming an emitter tip (16) integrally with and extending upward from the top surface (14) of the silicon carbide substrate (12), the emitter tip (16) having a radius of curvature less than 20 nanometers;
- depositing an insulator layer (18) on the top surface (14) of the silicon carbide substrate (12) and the emitter tip (16), the insulator layer (18) comprising a predetermined thickness;
- and
- forming an extractor electrode (20) on the insulator layer (18), the extractor electrode (20) comprising an extraction aperture (22) centered over the emitter tip (16), wherein a lower surface (24) of the extractor electrode (20) is closer to an apex (26) of the emitter tip (16) than the top surface (14) of the silicon carbide substrate (12).
A process for producing an electron beam with a silicon carbide based triode electron emitter 10, the process comprising:
- providing a silicon carbide based triode electron emitter (10) comprising:
- a silicon carbide substrate (12) comprising a top surface (14);
- an emitter tip (16) formed integrally with and extending upward from the top surface (14) of the silicon carbide substrate (12);
- an insulator layer (18) on the top surface (14) of the silicon carbide substrate (12) and the emitter tip (16);
- and an extractor electrode (20) on the insulator layer (18), the extractor electrode (20) comprising an extraction aperture (22) centered over the emitter tip (16);
- and
- applying a voltage between the extractor electrode (20) and the silicon carbide substrate (12) to produce an electric field sufficient to extract electrons from the emitter tip (16) by field emission.
Dependencies are inferred from the claim text.