Two-terminal switching device using a composite material of nanoscopic particles and carbon nanotubes

• US 9,337,423 B2
• Filed: 02/27/2015
• Issued: 05/10/2016
• Est. Priority Date: 11/19/2008
• Status: Active Grant

• Current Assignee: ZEON Corporation
• Original Assignee: Nantero Incorporated
• Inventors: Kocab, J. Thomas, Ghenciu, Eliodor G., Rueckes, Thomas, Yao, Thierry
• Primary Examiner(s): TOBERGTE, NICHOLAS J
• Application Number:
  US14/633,481
• Publication Number:
  US 20150188049A1
• Time in Patent Office: 438 Days
• Field of Search: 438/139, 257/109
• US Class Current: 1/1
• 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 13/0069 Writing or programming circuits or methods
• CPC Class Codes: G11C 13/025 using fullerenes, e.g. C60, or nanotubes, e.g. carbon or silicon nanotubes
• CPC Class Codes: G11C 2013/009 Write using potential difference applied between cell electrodes
• CPC Class Codes: G11C 2213/79 Array wherein the access device being a transistor
• CPC Class Codes: H10B 63/30 comprising selection components having three or more electrodes, e.g. transistors
• CPC Class Codes: H10K 10/50 Bistable switching devices
• CPC Class Codes: H10K 19/202 Integrated devices comprising a common active layer
• CPC Class Codes: H10K 71/12 using liquid deposition, e.g. spin coating
• CPC Class Codes: H10K 85/20 Carbon compounds, e.g. carbon nanotubes or fullerenes
• CPC Class Codes: H10K 85/221 Carbon nanotubes
• CPC Class Codes: H10N 70/021 Formation of the switching material, e.g. layer deposition
• CPC Class Codes: H10N 70/20 Multistable switching devices, e.g. memristors
• CPC Class Codes: H10N 70/231 based on solid-state phase change, e.g. between amorphous and crystalline phases, Ovshinsky effect
• CPC Class Codes: H10N 70/826 adapted for essentially vertical current flow, e.g. sandwich or pillar type devices
• CPC Class Codes: H10N 70/8845 Carbon or carbides
• CPC Class Codes: Y10T 428/25 Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles

Abstract

An improved switching material for forming a composite article over a substrate is disclosed. A first volume of nanotubes is combined with a second volume of nanoscopic particles in a predefined ration relative to the first volume of nanotubes to form a mixture. This mixture can then be deposited over a substrate as a relatively thick composite article via a spin coating process. The composite article may possess improved switching properties over that of a nanotube-only switching article. A method for forming substantially uniform nanoscopic particles of carbon, which contains one or more allotropes of carbon, is also disclosed.

Claims

1. A two-terminal switching device comprising:

a first electrode;

a second electrode; and

a switching composite article disposed between and in constant electrical communication with each of said first electrode and said second electrode of said two terminal switching device, wherein said composite article comprises a first volume of nanotubes and a second volume of nanoscopic particles in a predefined ratio relative to said first volume of nanotubes;

wherein at least one of said predefined ratio and said second volume of nanoscopic particles are selected in order to improve the switching functionality of said two-terminal switching device.

2. The two-terminal switching device of claim 1 wherein the nanotubes comprising said first volume are substantially all carbon nanotubes.

3. The two-terminal switching device of claim 1 wherein said second volume of nanoscopic particles includes nanoscopic particles containing at least one allotrope of carbon.

4. The two-terminal switching device of claim 1 wherein said second volume of nanoscopic particles includes silicon oxide particles.

5. The two-terminal switching device of claim 1 wherein said second volume of nanoscopic particles includes silicon nitride particles.

6. The two-terminal switching device of claim 1 wherein said second volume of nanoscopic particles includes multi-walled nanotubes.

7. The two-terminal switching device of claim 1 wherein substantially all of said nanoscopic particles within said second volume fall within a predetermined volume tolerance.

8. The two-terminal switching device of claim 1 wherein at least one of the magnitude of said first volume of nanotubes and the magnitude of said second volume of nanoscopic particles is selected to realize a desired volume density of nanotubes within said switching composite article.

9. The two-terminal switching device of claim 1, wherein said first volume of nanotubes form a matrix phase and said second volume of nanoscopic particles form a discrete phase.

10. The two-terminal switching device of claim 1, wherein said second volume of nanoscopic particles form a matrix phase and said first volume of nanotubes form a discrete phase.

11. The two-terminal switching device of claim 1, wherein said first volume of nanotubes and said second volume of nanoscopic particles form interconnected matrix phases.

12. The two-terminal switching device of claim 1, wherein said composite article has less than about 10¹¹ metal atoms/cm².

13. The two-terminal switching device of claim 1 wherein said second volume of nanoscopic particles includes atomic silicon.

14. The two-terminal switching device of claim 1 wherein said improved switching function is a reduced switching voltage.

15. The two-terminal switching device of claim 1 wherein said improved switching function is a faster switching time.