FACETED CATALYTIC DOTS FOR DIRECTED NANOTUBE GROWTH

• US 20090289245A1
• Filed: 09/19/2006
• Published: 11/26/2009
• Est. Priority Date: 09/19/2006
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Jin, Been-Yih, Chau, Robert S., Radosavljevic, Marko, Doyle, Brian S.
• Granted Patent: US 7,638,383 B2
• Time in Patent Office: Days
• US Class Current: 257/24
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: H01L 29/0665 the shape of the body defining a nanostructure nanotechnology per se B82B
• CPC Class Codes: H01L 29/0673 oriented parallel to a substrate
• CPC Class Codes: H01L 29/127 Quantum box structures
• CPC Class Codes: H10K 10/46 Field-effect transistors, e.g. organic thin-film transistors [OTFT] H10K10/43 takes precedence
• CPC Class Codes: H10K 10/462 Insulated gate field-effect transistors [IGFETs]
• CPC Class Codes: H10K 85/221 Carbon nanotubes
• CPC Class Codes: Y10S 977/72 On an electrically conducting, semi-conducting, or semi-insulating substrate
• CPC Class Codes: Y10S 977/721 On a silicon substrate
• CPC Class Codes: Y10S 977/742 Carbon nanotubes, CNTs
• CPC Class Codes: Y10S 977/858 including positioning/mounting nanostructure
• CPC Class Codes: Y10S 977/859 including substrate treatment

Abstract

Faceted catalytic dots are used for directing the growth of carbon nanotubes. In one example, a faceted dot is formed on a substrate for a microelectronic device. A growth promoting dopant is applied to a facet of the dot using an angled implant, and a carbon nanotube is grown on the doped facet of the dot.

Claims

1. A method comprising:

forming a self-assembled catalytic dot having a plurality of facets on a substrate for a microelectronic device;

growing a carbon nanotube on one of the facets of the dot to extend therefrom,

wherein the dot is doped to have a growth promoting layer on the facet on which the nanotube is grown and is doped to have a growth inhibiting layer on the others of the plurality of facets.

2. The method of claim 1, further comprising applying a growth inhibiting dopant to a facet of the dot using an angled implant and wherein growing comprises growing the carbon nanotube on a facet other than the inhibiting dopant-doped facet of the dot.

3. The method of claim 1, wherein forming comprises forming a self-assembled Ge dot.

4. The method of claim 1, wherein forming a faceted dot comprises depositing a wetting layer onto a portion of the substrate, depositing a catalytic layer over the wetting layer, and annealing the wetting and catalytic layers.

5. The method of claim 1 wherein:

forming comprises forming a self-assembled catalytic layer having a desired position and orientation on a substrate for a microelectronic device; and

wherein

the carbon nanotube has a form defined in part by the position and orientation of the catalytic layer.

8. The method of claim 5, wherein forming comprises doping the catalytic layer with a growth promoting material in a position at which the carbon nanotubes will be grown.

9. The method of claim 8, wherein doping comprises implanting the dopant at an angle that limits the dopant to locations at which carbon nanotubes are desired.

10. The method of claim 8, wherein doping comprises implanting a dopant with a low energy and a high dose.

12. The method of claim 5, wherein forming comprises doping with a growth inhibiting dopant across the surface of the substrate and then doping a selected portion of the catalytic layer with a growth promoting dopant.

13. The method of claim 5, wherein forming comprises forming over a source area, and wherein growing comprises growing from the source area to a drain area, the method further comprising forming contacts to the source and drain areas to form a transistor.

14. The method of claim 5, further comprising coating the carbon nanotubes with a gate dielectric.

15. The method of claim 5, wherein forming comprises forming a raised surface having angled facets, the method further comprising applying a growth promoting dopant to a facet of the raised surface by implanting a dopant at an angle and direction that is directed toward the facet.

6. (Canceled)

7. (Canceled)

11. (Canceled)

16. An apparatus comprising:

a self-assembled, catalytic dot on a microelectronic substrate, the dot having a plurality of facets; and

a carbon nanotube coupled to one of the plurality of facets and extending therefrom,

wherein the dot is doped to have a growth promoting layer on the facet to which the nanotube is coupled and is doped to have a growth inhibiting layer on the others of the plurality of facets.

17. The apparatus of claim 16, further comprising a transistor electrode on the substrate coupled to the dot.

18. The apparatus of claim 16, further comprising a second transistor electrode on the substrate and wherein the nanotube is coupled to the second transistor electrode at an end opposite the dot.

20. The apparatus of claim 16, further comprising a gate dielectric surrounding the carbon nanotube.

21. The apparatus of claim 16, wherein the faceted dot comprises Ge and wherein the facets are aligned to axes of the dot'"'"'s crystalline structure, and the facets are aligned to the substrate on which the dots are formed through annealing so that the carbon nanotube extends in direction aligned to the substrate.

22. The apparatus of claim 21, the facet coupled to the carbon nanotube has a multilayer wetting cladding layer annealed to self-assemble the dot, wherein the wetting layer comprises deposited Ge and the cladding layer comprises a catalytic metal.

19. (canceled)