Devices having horizontally-disposed nanofabric articles and methods of making the same

• US 20040181630A1
• Filed: 02/11/2004
• Published: 09/16/2004
• Est. Priority Date: 07/25/2001
• Status: Active Grant

• Current Assignee: Nantero Incorporated
• Original Assignee: Nantero Incorporated
• Inventors: Ward, Jonathan W., Segal, Brent M., Rueckes, Thomas, Jaiprakash, Venkatachalam C.
• Granted Patent: US 7,259,410 B2
• Time in Patent Office: Days
• US Class Current: 711/127
• CPC Class Codes: B81B 2203/0338 Channels
• CPC Class Codes: B81B 2203/04 Electrodes
• CPC Class Codes: B81C 1/00142 Bridges deformable micromirrors G02B26/0841
• CPC Class Codes: B81C 2201/0109 Sacrificial layers not provided for in B81C2201/0107 - B81C2201/0108
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: C01B 2202/02 Single-walled nanotubes
• CPC Class Codes: C01B 2202/22 Electronic properties
• CPC Class Codes: C01B 32/162 characterised by catalysts
• CPC Class Codes: G11C 11/56 using storage elements with more than two stable states represented by steps, e.g. of voltage, current, phase, frequency
• CPC Class Codes: G11C 13/025 using fullerenes, e.g. C60, or nanotubes, e.g. carbon or silicon nanotubes
• CPC Class Codes: G11C 2213/16 Memory cell being a nanotube, e.g. suspended nanotube
• CPC Class Codes: G11C 2213/77 Array wherein the memory element being directly connected to the bit lines and word lines without any access device being used
• CPC Class Codes: G11C 2213/81 Array wherein the array conductors, e.g. word lines, bit lines, are made of nanowires
• CPC Class Codes: G11C 23/00 Digital stores characterised by movement of mechanical parts to effect storage, e.g. using balls; Storage elements therefor
• CPC Class Codes: H01H 1/0094 Switches making use of nanoelectromechanical systems [NEMS]
• CPC Class Codes: H01L 21/76838 characterised by the formation and the after-treatment of the conductors etching for patterning the conductors H01L21/3213
• CPC Class Codes: H01L 2221/1094 Conducting structures comprising nanotubes or nanowires
• CPC Class Codes: H10K 85/221 Carbon nanotubes
• CPC Class Codes: Y10S 977/724 : Devices having flexible or movable element
• CPC Class Codes: Y10S 977/734 : Fullerenes, i.e. graphene-based structures, such as nanohorns, nanococoons, nanoscrolls or fullerene-like structures, e.g. WS2 or MoS2 chalcogenide nanotubes, planar C3N4, etc.
• CPC Class Codes: Y10S 977/742 : Carbon nanotubes, CNTs

Abstract

New devices having horizontally-disposed nanofabric articles and methods of making same are described. A discrete electromechanical device includes a structure having an electrically-conductive trace. A defined patch of nanotube fabric is disposed in spaced relation to the trace; and the defined patch of nanotube fabric is electromechanically deflectable between a first and second state. In the first state, the nanotube article is in spaced relation relative to the trace, and in the second state the nanotube article is in contact with the trace. A low resistance signal path is in electrical communication with the defined patch of nanofabric. Under certain embodiments, the structure includes a defined gap into which the electrically conductive trace is disposed. The defined gap has a defined width, and the defined patch of nanotube fabric spans the gap and has a longitudinal extent that is slightly longer than the defined width of the gap. Under certain embodiments, a clamp is disposed at each of two ends of the nanotube fabric segment and disposed over at least a portion of the nanotube fabric segment substantially at the edges defining the gap. Under certain embodiments, the clamp is made of electrically-conductive material. Under certain embodiments, the contact between the nanotube patch and the trace is a non-volatile state. Under certain embodiments, the contact between the nanotube patch and the trace is a volatile state. Under certain embodiments, the at least one electrically conductive trace has an interface material to alter the attractive force between the nanotube fabric segment and the electrically conductive trace.

Claims

1. A discrete electromechanical device, comprising:

a structure including an electrically-conductive trace;

a defined patch of nanotube fabric disposed in spaced relation to the trace; and

wherein the defined patch of nanotube fabric is electromechanically deflectable between a first and second state, wherein in the first state the nanotube article is in spaced relation relative to the trace, and wherein in the second state the nanotube article is in contact with the trace; and

a low resistance signal path in electrical communication with the defined patch of nanofabric.

2. The discrete electromechanical device of claim 1 wherein the low resistance signal path is a metal signal path in contact with the defined patch of nanotube fabric.

3. The discrete electromechanical device of claim 1 wherein the structure includes a defined gap into which the electrically conductive trace is disposed, wherein the defined gap has a defined width, and wherein the defined patch of nanotube fabric spans the gap and has a longitudinal extent that is slightly longer than the defined width of the gap.

4. A discrete electromechanical device, comprising:

a structure including a first and second electrically-conductive trace disposed substantially parallel to one another and in a spaced relation relative to one another;

a defined patch of nanotube fabric disposed between the first and second trace and extending substantially perpendicular to the first and second traces, wherein the defined patch of nanotube fabric is electromechanically deflectable into contact with at least one of the first and second traces in response to electrical stimulation of at least one of the first and second traces relative to the defined patch of nanotube fabric; and

a low resistance signal path in electrical communication with the defined patch of nanofabric.

5. The discrete electromechanical device of claim 4 wherein the low resistance signal path is a metal signal path in contact with the defined patch of nanotube fabric.

6. The discrete electromechanical device of claim 4 wherein the structure includes a defined gap into which one of the electrically conductive trace is disposed, wherein the defined gap has a defined width, and wherein the defined patch of nanotube fabric spans the gap and has a longitudinal extent that is slightly longer than the defined width of the gap.

7. A device, comprising:

a structure defining a gap having a gap width;

a defined segment of nanotube fabric, disposed on the structure and spanning the gap, the nanotube fabric segment including a plurality of nanotubes, at least some of said nanotubes having a length in excess of the gap width; and

a clamp, disposed at each of two ends of the nanotube fabric segment and disposed over at least a portion of the nanotube fabric segment substantially at the edges defining the gap.

8. The device of claim 7, wherein the clamp is made of electrically-conductive material.

9. The device of claim 7, wherein the clamp is made of electrically-insulative material having a via therethrough filled with electrically conductive material to provide an electrical communication path with the nanotube fabric segment.

10. The device of claim 9 wherein the via is filled with metal to provide a metallic signal path to the nanotube fabric segment.

11. The device of claim 9 wherein the nanotube fabric segment is made of a nanofabric having a porosity and wherein the electrically conductive material filling the via also fills at least some of the pores of the of the nanotube fabric segment.

12. The device of claim 7, wherein the nanotube fabric segment has a lithographically-defined shape.

13. The device of claim 7, further comprising an electrically-conductive trace disposed in the gap and being in spaced relation with the nanotube fabric segment.

14. The device of claim 7 wherein the clamp is a structure defining a second gap above the nanotube fabric segment and wherein the gap and the second gap each have respectively a conductive trace disposed therein.

15. The device of claim 7 wherein the nanotube fabric segment is made of a nanofabric having a porosity and wherein the clamp is made of material that fills at least some of the pores of the of the nanotube fabric segment.

16. The device of claim 7 further including at least one electrically conductive trace in spaced relation relative to the nanotube fabric segment and wherein the nanotube fabric segment is electromechanically deflectable into contact with trace in response to electrical stimulation of the trace and nanotube fabric segment.

17. The device of claim 16 wherein the contact with the trace is a non-volatile state.

18. The device of claim 16 wherein the contact with the trace is a volatile state.

19. The device of claim 16 wherein the at least one electrically conductive trace has an interface material to alter the attractive force between the nanotube fabric segment and the electrically conductive trace.

20. A method for making a device, comprising:

providing a structure having a gap of defined width;

forming a region of sacrificial material in the gap;

forming a nanotube fabric segment over the structure and region of sacrificial material;

at each end of the nanotube fabric segment providing a clamp over at least part of the nanotube fabric segment substantially at the edges defining the gap; and

removing the region of sacrificial material so that the nanotube fabric segment is suspended over and spanning the gap, clamped at each end of the article.

21. The method of claim 20 wherein the defined length of the nanotube fabric segment slightly exceeds the width of the gap.

22. The method of claim 20 wherein the clamp is formed of insulative material.

23. The method of claim 20 wherein the clamp is formed of electrically conductive material.

24. The method of claim 20 wherein forming the nanotube fabric segment includes forming a matted fabric of nanotubes and removing a portion of the fabric to yield the nanotube fabric segment.

25. The method of claim 24 wherein removing a portion of the fabric includes lithographically patterning and etching the fabric.

26. The method of claim 20 wherein the nanotube fabric segment is made of a porous nanofabric and wherein providing the clamp includes providing material that fills at least some of the pores of the nanotube fabric segment.

27. The method of claim 20, wherein the clamp is made of electrically-insulative material and the clamp is provided with a defined via therethrough, and wherein the method further includes filling the via with electrically conductive material to provide an electrical communication path with the nanotube fabric segment.

28. The method of claim 27 wherein the via is filled with metal to provide a metallic signal path to the nanotube fabric segment.

29. The method of claim 27 wherein the nanotube fabric segment is made of a nanofabric having a porosity and wherein the electrically conductive material filling the via also fills at least some of the pores of the of the nanotube fabric segment.

30. The method of claim 20, further comprising providing an electrically-conductive trace in the gap so as to be disposed under the region of sacrificial material.

31. The method of claim 20 wherein providing the clamp includes forming a structure defining a second gap above the nanotube fabric segment and wherein the method includes providing an electrically-conductive trace in the gap and the second gap.