Methods of nanotubes films and articles

• US 20050101112A1
• Filed: 12/13/2004
• Published: 05/12/2005
• Est. Priority Date: 07/25/2001
• Status: Active Grant

• Current Assignee: ZEON Corporation
• Original Assignee: Nantero Incorporated
• Inventors: Segal, Brent M., Rueckes, Thomas
• Granted Patent: US 7,264,990 B2
• Time in Patent Office: Days
• US Class Current: 438/584
• 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 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: H01L 27/1203 the substrate comprising an insulating body on a semiconductor body, e.g. SOI three-dimensional layout H01L27/0688
• CPC Class Codes: H01L 29/413 Nanosized electrodes, e.g. nanowire electrodes comprising one or a plurality of nanowires nanosized carbon materials, e.g. carbon nanotubes, per se C01B32/15; transparent electrodes comprising carbon nano-tubes H10K30/821, nanotechnology per se B82B
• CPC Class Codes: H10B 99/10 Memory cells having a cross-point geometry
• CPC Class Codes: H10K 30/821 comprising carbon nanotubes
• CPC Class Codes: H10K 85/221 Carbon nanotubes
• CPC Class Codes: Y10S 977/75 Single-walled
• CPC Class Codes: Y10S 977/778 within specified host or matrix material, e.g. nanocomposite films
• CPC Class Codes: Y10S 977/843 Gas phase catalytic growth, i.e. chemical vapor deposition
• CPC Class Codes: Y10S 977/857 including coating
• CPC Class Codes: Y10S 977/888 Shaping or removal of materials, e.g. etching

Abstract

Nanotube films and articles and methods of making the same are disclosed. A conductive article includes an aggregate of nanotube segments in which the nanotube segments contact other nanotube segments to define a plurality of conductive pathways along the article. The nanotube segments may be single walled carbon nanotubes, or multi-walled carbon nanotubes. The various segments may have different lengths and may include segments having a length shorter than the length of the article. The articles so formed may be disposed on substrates, and may form an electrical network of nanotubes within the article itself. Conductive articles may be made on a substrate by forming a nanotube fabric on the substrate, and defining a pattern within the fabric in which the pattern corresponds to the conductive article. The nanotube fabric may be formed by growing the nanotube fabric on the substrate using a catalyst, for example, in which the catalyst is a gas phase catalyst, or in which the catalyst is a metallic gas phase catalyst. The nanotube fabric may be formed by depositing a solution of suspended nanotubes on the substrate. The deposited solution may be spun to create a spin-coating of the solution. The solution may be deposited by dipping the substrate into the solution. The nanotube fabric is formed by spraying an aerosol having nanotubes onto a surface of the substrate.

Claims

1. A method of making a conductive article on a substrate, comprising:

forming a nanotube film on the substrate the film having a plurality of nanotubes extending in varying orientations but parallel to a facing surface of the substrate;

defining a pattern within the nanotube film, the pattern corresponding to the shape of the conductive article;

removing nanotubes in accordance with the pattern so that the remaining nanotube film forms the conductive article, wherein the remaining nanotube film includes at least one conductive pathway along a major axis of the conductive article.

2. The method of claim 1 wherein the nanotube film is formed by depositing a solution of suspended nanotubes on the substrate.

3. The method of claim 2 wherein the deposited solution is spun to create a spin-coating of the solution.

4. A method of making a conductive article on a substrate, comprising:

forming an accumulation of nanotubes on the substrate without forcing the nanotubes in alignment so that the orientation of each nanotube may vary relative to the other nanotubes;

removing some of the nanotubes in accordance with a lithographically-defined pattern so that the remaining nanotubes form the conductive article.

5. The method of claim 4 wherein the accumulation of nanotubes is formed by depositing a solution of suspended nanotubes on the substrate.

6. The method of claim 5 wherein the deposited solution is spun to create a spin-coating of the solution.

7. A method of making a conductive article on a substrate, comprising:

providing a substantially planar fabric of pre-formed nanotubes on the substrate;

removing some of the nanotubes in accordance with a predefined pattern wherein the pattern defines the shape of the conductive article.

8. The method of claim 7 wherein the nanotubes are applied via a spin-coating operation.

9. The method of claim 7 wherein the fabric has controlled density.

10. The method of claim 7 wherein the fabric is substantially a monolayer of nanotubes.

11. The method of claim 8 wherein the thickness of the web is controlled via adjusting parameters of the spin coating operation.

12. The method of claim 8 wherein the thickness of the fabric is controlled via adjusting a spin profile of the spin coating operation.

13. The method of claim 8 wherein the thickness of the fabric is controlled via adjusting a spin-coating speed of the spin coating operation.

14. The method of claim 8 wherein the thickness of the fabric is controlled via adjusting a surface functionalization of a surface of the substrate.

15. The method of claim 8 wherein the thickness of the fabric is controlled via adjusting a surface pH of the substrate.

16. The method of claim 8 wherein the thickness of the fabric is controlled via adjusting the temperature of the environment of the spin coating operation.

17. The method of claim 8 wherein the thickness of the fabric is controlled via adjusting the duration of the spin coating operation.

18. A method of making a conductive article having a predefined shape on a substrate, comprising:

providing plurality of nanotubes on the substrate wherein the nanotubes are in electrical contact, wherein the predefined shape has a predefined orientation and wherein the nanotubes are not individually constrained to said orientation.;

removing some of the nanotubes in accordance with a predefined pattern wherein the pattern defines the shape of the conductive article.