Systems and methods for implementing robust carbon nanotube-based field emitters

Patent metadata

Field	Value
Publication number	US-9064667-B2
Application number	US-201314081932-A
Country	US
Kind code	B2
Filing date	Nov 15, 2013
Priority date	Nov 15, 2012
Publication date	Jun 23, 2015
Grant date	Jun 23, 2015

Abstract

Systems and methods in accordance with embodiments of the invention implement carbon nanotube-based field emitters. In one embodiment, a method of fabricating a carbon nanotube field emitter includes: patterning a substrate with a catalyst, where the substrate has thereon disposed a diffusion barrier layer; growing a plurality of carbon nanotubes on at least a portion of the patterned catalyst; and heating the substrate to an extent where it begins to soften such that at least a portion of at least one carbon nanotube becomes enveloped by the softened substrate.

First claim

What is claimed is:

1. A method of fabricating a carbon nanotube-based field emitter, comprising:
patterning a substrate with a catalyst;
wherein the substrate has thereon disposed a diffusion barrier layer;

growing a plurality of carbon nanotubes on at least a portion of the patterned catalyst; and
heating the substrate, in the absence of any growth gases, to an extent where it begins to soften such that at least a portion of at least one carbon nanotube becomes enveloped by the softened substrate.

2. The method of claim 1 , wherein the catalyst comprises one of: Fe, Cu, Cr, and Al.

3. The method of claim 1 , wherein the substrate comprises a metallic material.

4. The method of claim 1 , further comprising allowing the grown carbon nanotubes and the softened substrate to cool to room temperature.

5. The method of claim 4 , wherein the substrate comprises titanium.

6. The method of claim 5 , wherein the diffusion barrier layer comprises aluminum oxide.

7. The method of claim 5 , wherein the catalyst is patterned on to the substrate in the form of a plurality of dots.

8. The method of claim 6 , wherein the diffusion barrier layer has a thickness of less than approximately 30 angstroms.

9. The method of claim 7 , wherein the catalyst pattern is created using a lift-off process.

10. The method of claim 7 , wherein the grown plurality of carbon nanotubes are in the form of bundles of carbon nanotubes, wherein each bundle of carbon nanotubes corresponds with one dot.

11. The method of claim 7 , wherein the carbon nanotubes are grown using a gaseous hydrocarbon.

12. The method of claim 9 , wherein the thickness of the patterned catalyst is less than approximately 35 angstroms.

13. The method of claim 12 , wherein the gaseous hydrocarbon is one of:
ethylene, acetylene, methane, and mixtures thereof.

14. The method of claim 10 , wherein the diameter of each bundle of carbon nanotubes is between approximately 1 micrometer and 2 micrometers.

15. The method of claim 10 , wherein the carbon nanotubes are grown at a temperature from between 575° C. and 775° C.

16. The method of claim 10 , wherein the carbon nanotubes are grown for a duration of approximately 30 minutes.

17. The method of claim 10 , wherein the carbon nanotubes are grown to a height of between approximately 25 micrometers and 50 micrometers.

18. The method of claim 10 , further comprising subjecting the grown carbon nanotubes and the substrate to an argon flow prior to heating the substrate to an extent that it begins to soften.

19. The method of claim 14 , wherein an edge of each bundle of carbon nanotubes is approximately 5 micrometers away from the nearest edge of an adjacent bundle of nanotubes.

20. The method of claim 18 , wherein the heating of the substrate to an extent that it begins to soften occurs in an environment comprising a substantially inert gas.

21. The method of claim 20 , wherein the substantially inert gas is argon.

22. The method of claim 21 , wherein the substrate is heated to 1050° C.

23. The method of claim 22 , wherein the substrate is heated for between approximately 15 minutes and approximately 30 minutes.

24. A method of fabricating a carbon nanotube-based field emitter, comprising:
patterning a substrate with a catalyst;
wherein the substrate comprises titanium;
wherein the substrate has thereon disposed a diffusion barrier layer; and
wherein the catalyst is patterned on to the substrate in the form of a plurality of dots;

growing a plurality of carbon nanotubes on at least a portion of the patterned catalyst;
wherein the grown carbon nanotubes are in the form of bundles of carbon
nanotubes, each bundle of carbon nanotubes corresponding with one dot; subjecting the grown carbon nanotubes and the substrate to an argon flow; heating the substrate in an environment comprising a substantially inert gas to an extent where the substrate begins to soften such that at least a portion of at least one carbon nanotube becomes enveloped by the softened substrate; and allowing the grown carbon nanotubes and the softened substrate to cool to room temperature.

25. The method of claim 24 , wherein the substantially inert gas is Argon.

26. The method of claim 24 , wherein the substrate is heated to 1050° C.

27. The method of claim 24 , wherein the substrate is heated for between approximately 15 minutes and approximately 30 minutes.

28. A method of fabricating a carbon nanotube-based field emitter, comprising:
patterning a substrate with a catalyst;
wherein the substrate comprises a metallic material;
wherein the substrate has thereon disposed a diffusion barrier layer; and
wherein the catalyst is patterned on to the substrate in the form of a plurality of dots;

growing a plurality of carbon nanotubes on at least a portion of the patterned catalyst;
wherein the grown carbon nanotubes are in the form of bundles of carbon
nanotubes, each bundle of carbon nanotubes corresponding with one dot; subjecting the grown carbon nanotubes and the substrate to an argon flow; heating the substrate in an environment comprising a substantially inert gas to an extent where the substrate begins to soften such that at least a portion of at least one carbon nanotube becomes enveloped by the softened substrate; and allowing the grown carbon nanotubes and the softened substrate to cool to room temperature.

Assignees

• California Inst Of Techn

Inventors

• Manohara Harish
• Kristof Valerie
• Toda Risaku

Classifications

• H01J9/025 Primary

  of field emission cathodes · CPC title

• B82Y40/00

  Manufacture or treatment of nanostructures · CPC title

• H01J9/022

  of cold cathodes · CPC title

• Y10S977/939

  Electron emitter, e.g. spindt emitter tip coated with nanoparticles · CPC title