Nanoelectronic sensor system and hydrogen-sensitive functionalization

• US 20060263255A1
• Filed: 02/14/2006
• Published: 11/23/2006
• Est. Priority Date: 09/04/2002
• Status: Abandoned Application

• Current Assignee: Nanomix Incorporated (CJY Holdings Ltd.)
• Original Assignee: Nanomix Incorporated (CJY Holdings Ltd.)
• Inventors: Bradley, Keith, Gabriel, Jean-Christophe P., Collins, Philip G., Skarupo, Sergei, Passmore, John Loren, Star, Alexander, Olson, Darin, Han, Tzong-Ru
• Application Number:
  US11/354,561
• Publication Number:
  US 20060263255A1
• Time in Patent Office: Days
• US Class Current: 422/83
• 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 15/00 Nanotechnology for interacting, sensing or actuating, e.g. quantum dots as markers in protein assays or molecular motors
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: G01N 27/4141 specially adapted for gases
• CPC Class Codes: G01N 27/4146 involving nanosized elements, e.g. nanotubes, nanowires
• CPC Class Codes: G01N 33/005 for H2

Abstract

A new sensing technology for chemical/biomolecular sensors is provided. One such sensor detects molecular hydrogen (H₂) using nanoelectronic components. A tiny, low-cost nanosensor chip can offer: (i) performance that matches or exceeds that of existing technology, (ii) plug-and-play simplicity with both digital and analog control systems, and (ii) the small size and low power consumption needed for wireless integration.

Claims

1. A nanostructure sensing device, comprising:

a substrate;

a first nanostructure disposed over the substrate, the nanostructure having a functionalization sensitive to at least one selected analyte;

a first conductive element disposed over the substrate and forming a first electrical junction with a first nanostructure; and

a second conductive element disposed over the substrate and forming a second electrical junction with the first nanostructure.

2. The nanostructure sensing device of claim 1, wherein the first nanostructure includes one or more nanoparticles selected from the group consisting of nanotubes, nanowires, nanofibers, and nanorods.

3. The nanostructure sensing device of claim 1, further comprising a gate electrode in proximity to the first nanostructure.

4. The nanostructure sensing device of claim 3, wherein the gate electrode includes at least one of an undifferentiated gate electrode, a back gate electrode, a top gate electrode, a liquid gate electrode, and a side gate electrode.

5. The nanostructure sensing device of claim 2, wherein the first nanostructure comprises a network of nanotubes.

6. The nanostructure sensing device of claim 5, wherein the first nanostructure comprises a network including a plurality of interconnecting single wall carbon nanotubes.

7. The nanostructure sensing device of claim 5, wherein the substrate comprises a surface layer structure facing the first nanostructure.

8. The nanostructure sensing device of claim 7, wherein surface layer structure comprises a material selected from the group consisting of semiconductors, semiconductor oxides, semiconductor nitrides, and combinations thereof.

9. The nanostructure sensing device of claim 7, wherein the surface layer structure comprises a top layer configured to favor the catalytic growth of carbon nanotubes.

10. The nanostructure sensing device of claim 9, wherein the top layer top layer comprises a nano-scale smooth layer of SiO2.

11. The nanostructure sensing device of claim 7, wherein the surface layer structure comprises a substrate contaminant protection layer.

12. The nanostructure sensing device of claim 11, wherein the substrate contaminant protection layer comprises a diffusion barrier to metals.

13. The nanostructure sensing device of claim 12, wherein the diffusion barrier to metals comprises Si3N4.

14. The nanostructure sensing device of claim 12, wherein the diffusion barrier to metals comprises a layer of Si3N4 from about 50 to about 3000 nm thick.

15. The nanostructure sensing device of claim 12, wherein the diffusion barrier to metals comprises a layer of Si3N4 from about 50 to about 1000 nm thick.

16. The nanostructure sensing device of claim 7, wherein surface layer structure comprises a gate dielectric.

17. The nanostructure sensing device of claim 1, wherein the functionalization is sensitive to hydrogen.

18. The nanostructure sensing device of claim 17, wherein the functionalization comprises at least a partial coating of the nanostructure with at least one transition metal

19. The nanostructure sensing device of claim 18, wherein the transition metal is selected from the group consisting of palladium, platinum, and nickel.

20. The nanostructure sensing device of claim 18, wherein the at least one transition metal comprises Pd in an alloy including one or more elements selected from Pt, Au, Ni, Ti, and Cu.

21. The nanostructure sensing device of claim 20, wherein the at least one transition metal comprises Pd in an alloy including about 16% w/w of Ni.

22. The nanostructure sensing device of claim 5, wherein the network is formed on the substrate using a chemical vapor deposition process.

23. The nanostructure sensing device of claim 5, wherein the network is formed by means of vacuum deposition of a nanotube fluid suspension upon a porous surface.

24. The nanostructure sensing device of claim 1, further comprising passivation material covering at least a portion of the first nanostructure.

25. The nanostructure sensing device of claim 24, wherein the passivation material substantially covers the portions of the nanostructure which are contiguous with the first electrode and the second electrode.

26. The nanostructure sensing device of claim 24, wherein the passivation material is impermeable to at least one species.

27. The nanostructure sensing device of claim 24, wherein the passivation material is substantially impermeable to water.

28. The nanostructure sensing device of claim 24, wherein the passivation material comprises more than one layer of material.

29. The nanostructure sensing device of claim 24, wherein the thickness of the passivation material is chosen to tune sensitivity to the analyte of the nanostructure sensing device.

30. The nanostructure sensing device of claim 24, wherein the passivation material includes at least one constituent selected from the group consisting of silicon oxides, fluorinated, hydrogenated and carbonated silicon oxides, silicon nitride, metal oxides, and combinations thereof.

31. The nanostructure sensing device of claim 24, wherein the passivation material includes at least one constituent selected from the group consisting of Teflon™

, Nafion™

, polyethylene and polypropylene.

32. The nanostructure sensing device of claim 24, wherein the passivation material includes at least one constituent selected from the group consisting of SiO2, SiO, Si3N4, A12O3, Parylene, organic polymer, hydrophobic polymer, and a fluoropolymer.

33. The nanostructure sensing device of claim 24, wherein the passivation material reduces cross sensitivity of the device.

34. The nanostructure sensing device of claim 24, wherein the passivation material is a least partially permeable to hydrogen.

35. The nanostructure sensing device of claim 34, wherein the thickness of the passivation material is chosen to tune selectivity for hydrogen of the nanostructure sensing device.

36. The nanostructure sensing device of claim 35, wherein the passivation material has a thickness between about 3 nm and 500 nm.

37. The nanostructure sensing device of claim 1, wherein the functionalization sensitive to at least one selected analyte includes at least one recognition material, wherein the recognition material is disposed adjacent the nanostructure, and wherein the recognition material is separated from the nanostructure by a dielectric layer.

38. The nanostructure sensing device of claim 37, wherein the nanostructure includes a network of carbon nanotubes disposed upon a substrate.

39. The nanostructure sensing device of claim 38, wherein at least a portion of the recognition material is conductive, and wherein at least a portion of the recognition material is connectable to an electrical lead so as to form a gate electrode.

40. A substrate for a nanoelectronic device, comprising:

a substrate base;

a first layer disposed over the substrate base comprising a material substantially impermeable to the diffusion of metallic elements during carbon nanotube growth upon the substrate by chemical vapor deposition; and

a second layer disposed over the first layer and comprising a material configured to favor the catalytic growth of carbon nanotubes.

41. A substrate as in claim 40, wherein the substrate base comprises a semiconductor material.

42. A substrate as in claim 41, wherein the semiconductor material comprises silicon.

43. A substrate as in claim 40, wherein the first layer comprises Si₃N₄.

44. A substrate as in claim 43, wherein the first layer is from about 50 to about 3000 nm thick.

45. A substrate as in claim 43, wherein the first layer is from about 50 to about 1000 nm thick.

46. A substrate as in claim 40, wherein the second layer provides a surface promoting consistent growth of carbon nanotubes upon the substrate by chemical vapor deposition.

47. A substrate as in claim 40, wherein the second layer comprises SiO₂.

48. A substrate as in claim 40, wherein one or more of the first layer and the second layer comprises a gate dielectric.