METHOD OF MAKING AN APPLICATOR LIQUID FOR ELECTRONICS FABRICATION PROCESS

• US 20090140213A1
• Filed: 06/03/2004
• Published: 06/04/2009
• Est. Priority Date: 06/03/2004
• Status: Active Grant

• Current Assignee: ZEON Corporation
• Original Assignee: Nantero Incorporated
• Inventors: Sivarajan, Ramesh, Segal, Brent M., Rueckes, Thomas, Sen, Rahul
• Granted Patent: US 7,556,746 B2
• Time in Patent Office: Days
• US Class Current: 252/502
• 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 32/168 After-treatment
• CPC Class Codes: C01B 32/17 Purification
• CPC Class Codes: H10K 71/15 characterised by the solvent used
• CPC Class Codes: H10K 85/221 Carbon nanotubes
• 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

Abstract

Certain spin-coatable liquids and application techniques are described, which can be used to form nanotube films or fabrics of controlled properties. A method of making an applicator liquid containing nanotubes for use in an electronics fabrication process includes characterizing an electronic fabrication process according to fabrication compatible solvents and allowable levels of metallic and particle impurities; providing nanotubes that satisfy the allowable impurities criteria for the electronics fabrication process; providing a solvent that meets the fabrication compatible solvents and allowable impurities criteria for the electronic fabrication process; and dispersing the nanotubes into the solvent at a concentration of at least one milligram of nanotubes per liter solvent to form an applicator liquid.

Claims

1. A method of making an applicator liquid containing nanotubes of high purity while achieving a stable distribution of nanotubes in the liquid for use in an electronics fabrication process, comprising:

dispersing nanotubes into a solvent at a concentration of at least one milligram of nanotubes per liter solvent without addition of surfactants or polymers to form the applicator liquid;

wherein the applicator liquid is substantially free of particulates having a diameter greater than about 500 nm;

wherein the applicator liquid has a level of metal impurities that is less than about 1×

10¹⁸ atoms/cm³; and

wherein the nanotubes are distributed in the solvent without substantial precipitation or flocculation.

2. The method of claim 1, wherein the electronics fabrication process comprises a semiconductor fabrication.

3. The method of claim 1, wherein the electronics fabrication process comprises an advanced logic and memory fabrication.

4. The method of claim 1, wherein the electronics fabrication process comprises interconnect fabrication.

5. The method of claim 1, wherein the electronics fabrication process comprises chemical or biological sensor fabrication.

6. The method of claim 1, wherein said dispersing the nanotube into the solvent comprises:

introducing a plurality of nanotube into the solvent to form a mixture; and

agitating the mixture to disperse the nanotubes.

8. The method of claim 6, wherein said agitating the mixture comprises sonicating the mixture.

9. The method of claim 8, further comprising:

centrifuging the sonicated mixture to separate a sediment from a supernatant, and collecting the supernatant containing nanotubes.

10. The method of claim 9, further comprising mixing the sediment with an additional portion of the solvent, sonicating the mixture, centrifuging the sonicated mixture to separate a sediment from a supernatant, and collecting the supernatant containing nanotubes.

11. The method of claim 10, wherein said mixing, sonicating, centrifuging and collecting are repeated one or more times.

12. The method of claim 1, wherein nanotubes are pretreated to remove metallic impurities to provide nanotubes that have a level of metal impurities that is less than about 1×

10¹⁸ atoms/cm³.

13. The method of claim 12, wherein the pretreatment comprises dispersing the nanotubes in an acid solution to dissolve metal impurities.

15. The method of claim 12, wherein the the nanotubes have a level of metal impurities that is less than about 15×

10¹⁰ atoms/cm².

16. The method of claim 1, wherein the nanotubes are pretreated to remove particle impurities to provide nanotubes that are substantially free of particulates having a diameter greater than about 500 nm.

17. The method of claim 16, wherein the pretreatment comprises removing particle impurities by filtration.

18. The method of claim 16, wherein the nanotubes are substantially free of particulate impurities having a diameter of greater than about 300 nm.

19. The method of claim 16 wherein the nanotubes are substantially free of particulate impurities having a diameter of greater than about 100 nm.

20. The method of claim 16, wherein the nanotubes are substantially free of particulate impurities having a diameter of greater than about 45 nm.

22. The method of claim 1, wherein said dispersing the nanotubes into the solvent comprises:

introducing a plurality of nanotube into the solvent to form a mixture; and

sonicating the mixture;

centrifuging the sonicated mixture; and

removing the supernatant containing dispersed nanotubes.

25. The method of claim 22, wherein the applicator liquid comprises less than about 10×

10¹⁷ atoms/cm³ of metal impurities.

26. The method of claim 22, wherein the applicator liquid comprises less than about 10×

10¹⁷ atoms/cm³ of heavy metal impurities.

27. The method of claim 22, wherein the applicator liquid comprises less than about 10×

10¹⁷ atoms/cm³ of group I and group II element impurities.

28. The method of claim 22, wherein the applicator liquid comprises less than about 10×

10¹⁷ atoms/cm³ of transition metal impurities.

29. The method of claim 22, wherein the applicator liquid comprises less than about 15×

10¹⁰ atoms/cm³ of metal impurities.

30. The method of claim 22, wherein the applicator liquid comprises less than about 10×

10¹⁰ atoms/cm³ of heavy metal impurities.

31. The method of claim 22, wherein the applicator liquid comprises less than about 10×

10¹⁰ atoms/cm³ of group I and group II element impurities.

32. The method of claim 22, wherein the applicator liquid comprises less than about 10×

10¹⁰ atoms/cm³ of transition metal impurities.

34. The method of claim 22, wherein the applicator liquid is substantially free of particle impurities having a diameter of greater than about 300 nm.

35. The method of claim 22, wherein the applicator liquid is substantially free of particle impurities having a diameter of greater than about 100 nm.

36. The method of claim 22, wherein the applicator liquid is substantially free of particle impurities having a diameter of greater than about 45 nm.

7. (canceled)

14. (canceled)

21. (canceled)

23-24. -24. (canceled)

33. (canceled)