Methodology for electrically induced selective breakdown of nanotubes

• US 6,423,583 B1
• Filed: 01/03/2001
• Issued: 07/23/2002
• Est. Priority Date: 01/03/2001
• Status: Expired due to Term

• Current Assignee: Globalfoundries US Incorporated (GlobalFoundries, Inc.)
• Original Assignee: International Business Machines Corporation
• Inventors: Collins, Philip G., Martel, Richard, Avouris, Phaedon
• Primary Examiner(s): Sherry, Michael J.
• Assistant Examiner(s): PERT, EVAN T
• Application Number:
  US09/753,845
• Time in Patent Office: 566 Days
• Field of Search: 438/128, 438/131, 438/132, 438/142, 438/149, 438/151, 438/800
• US Class Current: 438/132
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: G11C 2213/17 Memory cell being a nanowire transistor
• CPC Class Codes: G11C 2213/18 Memory cell being a nanowire having RADIAL composition
• CPC Class Codes: H10K 10/462 Insulated gate field-effect transistors [IGFETs]
• CPC Class Codes: H10K 10/466 Lateral bottom-gate IGFETs comprising only a single gate
• CPC Class Codes: H10K 85/221 Carbon nanotubes
• CPC Class Codes: Y10S 977/742 Carbon nanotubes, CNTs
• CPC Class Codes: Y10S 977/845 Purification or separation of fullerenes or nanotubes
• CPC Class Codes: Y10S 977/847 Surface modifications, e.g. functionalization, coating
• CPC Class Codes: Y10S 977/888 Shaping or removal of materials, e.g. etching
• CPC Class Codes: Y10S 977/89 Deposition of materials, e.g. coating, cvd, or ald
• CPC Class Codes: Y10S 977/896 Chemical synthesis, e.g. chemical bonding or breaking
• CPC Class Codes: Y10S 977/938 Field effect transistors, FETS, with nanowire- or nanotube-channel region

Abstract

A method is provided for forming a device. The method provides an insulating substrate including a source electrode, a drain electrode, and a gate electrode. The method provides carbon nanotube bundles including metallic and semiconducting component nanotubes in contact with the substrate. The method applies a voltage to the gate electrode to deplete the semiconducting component nanotubes of carriers, applies an electrical current through the nanotube, from a source electrode to a drain electrode, and breaks at least one metallic component nanotube to form a field effect transistor. The carbon nanotube bundle can be a multi-walled nanotube or a single-walled nanotube rope.

Claims

1. A method for forming a device comprising the steps of:

providing a substrate;

providing a plurality of nanotubes in contact with the substrate; and

selectively breaking a nanotube using an electrical current.

2. The method of claim 1, further comprising the step of depleting a semiconducting nanotube of a plurality of carriers.

3. The method of claim 2, wherein the step of depleting a semiconducting nanotube of a plurality of carriers further comprises the step of applying a voltage to a gate electrode on the substrate.

4. The method of claim 3, further comprising the step of applying the electrical current through the nanotube from a source electrode to a drain electrode.

5. The method of claim 1, wherein the plurality of nanotubes are multi-walled nanotubes including metallic and semiconducting nanotubes.

6. The method of claim 5, wherein the step of selectively breaking includes breaking an outer metallic nanotube.

7. The method of claim 1, wherein the plurality of nanotubes are single-walled nanotube ropes including metallic and semiconducting nanotubes.

8. The method of claim 7, wherein the step of breaking includes breaking at least one metallic nanotube.

9. The method of claim 1, wherein the nanotubes are provided at a density between a monolayer and about {fraction (1/10)}th of one percent coverage.

10. The method of claim 1, wherein the substrate is an insulator and includes an array of metallic pads.

11. The method of claim 10, wherein the substrate is silica based and includes the array of metallic pads.

12. The method of claim 11, wherein each pad includes one of a source electrode, a drain electrode, and a gate electrode.

13. The method of claim 1, wherein the step of providing a substrate is accomplished using lithography to form an array of pads, each pad including a corresponding electrode on an insulating substrate.

14. The method of claim 1, wherein the nanotubes are carbon nanotubes.

15. The method of claim 1, further comprising the step of breaking a plurality of stray nanotubes.

16. A method of modifying at least one characteristic of a nanotube comprising the steps of:

providing a mixture of nanotubes; and

applying a current to the mixture, inducing the selective breakdown of the nanotube mixture.

17. The method of claim 16, further comprising the step of removing a plurality of carriers from a semiconducting nanotube.

18. The method of claim 17, wherein the current selectively breaks metallic nanotubes.

19. The method of claim 18, wherein power applied to the mixture is about 500 μ

W.

20. The method of claim 16, wherein the nanotube is one of a multi-walled nanotube and a single-walled nanotube rope.

21. The method of claim 16, wherein the characteristic is one of diameter, density, and conductance.

22. The method of claim 16, wherein the mixture includes metallic and semiconducting nanotubes.

23. The method of claim 16, wherein the current density is greater than 10⁹ A/cm².

24. A method for forming a device comprising the steps of:

providing an insulating substrate including a source electrode, a drain electrode, and a gate electrode;

providing a plurality of carbon nanotube bundles including metallic and semiconducting component nanotubes in contact with the substrate, wherein the nanotubes are provided at a density of about one percent coverage;

applying a voltage to the gate electrode to deplete the semiconducting component nanotubes of a plurality of carriers;

applying an electrical current through the nanotube, from a source electrode to a drain electrode; and

breaking at least one metallic component nanotube to form a field effect transistor.

25. The method of claim 24, wherein the carbon nanotube bundle is one of a multi-walled nanotube and a single-walled nanotube rope.