Method of horizontally growing carbon nanotubes and field effect transistor using the carbon nanotubes grown by the method

• US 6,803,260 B2
• Filed: 10/18/2002
• Issued: 10/12/2004
• Est. Priority Date: 07/18/2000
• Status: Expired due to Fees

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Kim, Kyu Tae, Han, Young Soo, Lee, Jae Eun, Shin, Jin Koog, Yoon, Sang Soo, Jung, Min Jae
• Primary Examiner(s): WILLE, DOUGLAS A
• Application Number:
  US10/273,188
• Publication Number:
  US 20040164327A1
• Time in Patent Office: 725 Days
• Field of Search: 257/142
• US Class Current: 438/142
• 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 2202/08 Aligned nanotubes
• CPC Class Codes: C01B 32/162 characterised by catalysts
• CPC Class Codes: G11C 13/025 using fullerenes, e.g. C60, or nanotubes, e.g. carbon or silicon nanotubes
• CPC Class Codes: G11C 2213/17 Memory cell being a nanowire transistor
• CPC Class Codes: H10K 10/00 Organic devices specially adapted for rectifying, amplifying, oscillating or switching; Organic capacitors or resistors having potential barriers integrated devices or assemblies of multiple devices H10K19/00
• CPC Class Codes: H10K 10/46 Field-effect transistors, e.g. organic thin-film transistors [OTFT] H10K10/43 takes precedence
• CPC Class Codes: H10K 10/462 Insulated gate field-effect transistors [IGFETs]
• CPC Class Codes: H10K 10/466 Lateral bottom-gate IGFETs comprising only a single gate
• CPC Class Codes: H10K 10/491 Vertical transistors, e.g. vertical carbon nanotube field effect transistors [CNT-FETs]
• CPC Class Codes: H10K 19/00 Integrated devices, or assemblies of multiple devices, comprising at least one organic element specially adapted for rectifying, amplifying, oscillating or switching, covered by group H10K10/00
• CPC Class Codes: H10K 71/10 Deposition of organic active material
• CPC Class Codes: H10K 85/221 Carbon nanotubes
• CPC Class Codes: Y10S 977/742 Carbon nanotubes, CNTs
• CPC Class Codes: Y10S 977/843 Gas phase catalytic growth, i.e. chemical vapor deposition
• CPC Class Codes: Y10S 977/844 Growth by vaporization or dissociation of carbon source using a high-energy heat source, e.g. electric arc, laser, plasma, e-beam
• CPC Class Codes: Y10S 977/89 Deposition of materials, e.g. coating, cvd, or ald
• CPC Class Codes: Y10S 977/896 Chemical synthesis, e.g. chemical bonding or breaking
• CPC Class Codes: Y10S 977/90 : having step or means utilizing mechanical or thermal property, e.g. pressure, heat
• CPC Class Codes: Y10S 977/936 : in a transistor or 3-terminal device
• CPC Class Codes: Y10S 977/938 : Field effect transistors, FETS, with nanowire- or nanotube-channel region

Abstract

Disclosed is a method of horizontally growing carbon nanotubes, in which the carbon nanotubes can be selectively grown in a horizontal direction at specific locations of a substrate having catalyst formed thereat, so that the method can be usefully utilized in fabricating nano-devices. The method includes the steps of: (a) forming a predetermined catalyst pattern on a first substrate; (b) forming a vertical growth preventing layer on the first substrate, which prevents carbon nanotubes from growing in a vertical direction; (c) forming apertures through the vertical growth preventing layer and the first substrate to expose the catalyst pattern through the apertures; and (d) synthesizing carbon nanotubes at exposed surfaces of the catalyst pattern in order to grow the carbon nanotubes in the horizontal direction.

Claims

1. A method of horizontally growing carbon nanotubes, comprising:

(a) forming a predetermined catalyst pattern on a first substrate;

(b) forming a vertical growth preventing layer on the first substrate, which prevents carbon nanotubes from growing in a vertical direction;

(c) forming apertures through the vertical growth preventing layer and at least partially through the first substrate to expose surfaces of the catalyst pattern through the apertures; and

(d) synthesizing carbon nanotubes at the exposed surfaces of the catalyst pattern to grow the carbon nanotubes in the horizontal direction.

2. A method as claimed in claim 1, wherein the formed apertures comprise a hole-type, in which the apertures extend entirely through the vertical growth preventing layer and the first substrate.

3. A method as claimed in claim 1, wherein the formed apertures comprise a well-type, in which the vertical growth preventing layer is entirely etched and the first substrate is partially etched, so that the apertures extend through the vertical growth preventing layer and a portion of the first substrate.

4. A method as claimed in claim 1, wherein the catalyst pattern has one from a straight-line shape, an intersection shape, a radial shape, a circular shape, and a rectangular shape, while the apertures are formed at intersecting areas of the catalyst pattern of a straight line shape, an intersection shape, and a radial shape, at an interior of a circle, and at an interior of a rectangle of the pattern.

5. A method as claimed in claim 4, wherein the carbon nanotubes formed respectively from the exposed surfaces of the catalyst pattern are grown to form a junction between them.

6. A method as claimed in claim 5, wherein the junction between the carbon nanotubes is formed by a phenomenon of thermal contraction of material which is generated in a cooling stage after the carbon nanotubes are grown.

7. A method as claimed in claim 4, wherein the carbon nanotubes formed from the exposed surfaces of the catalyst pattern interest each other.

8. A method as claimed in claim 1, wherein the grown carbon nanotubes form a bridge construction, by which exposed surfaces of the catalyst pattern opposing each other are connected with each other.

9. A method as claimed in claim 1, wherein the grown carbon nanotubes form a free-hang construction, in which the carbon nanotubes from the exposed surfaces of the catalyst pattern opposing each other are separated from each other.

10. A method as claimed in claim 1, wherein the grown carbon nanotubes are a plurality of carbon nanotubes grown at a single catalyst pattern.

11. A method as claimed in claim 1, wherein the grown carbon nanotubes form a mesh construction, in which a plurality of carbon nanotubes are grown from each of the exposed surfaces of catalyst pattern opposing each other, to be connected with each other.

12. A method as claimed in claim 1, further comprising patterning a metal, to intersect with at least one grown carbon nanotube so as to selectively form a junction between the at least one grown carbon nanotube and the metal at a specific location.

13. A method of horizontally growing carbon nanotubes, comprising:

(i) forming masks at predetermined locations on a first substrate;

(j) forming a catalyst pattern on the first substrate and the masks formed on the first substrate;

k) forming a vertical growth preventing layer on the first substrate, which prevents the carbon nanotubes from growing in a vertical direction;

(l) eliminating the masks from the vertical growth preventing layer and the first substrate to form apertures and expose surfaces of the catalyst pattern; and

(m) synthesizing the carbon nanotubes at the exposed surfaces of the catalyst pattern to grow the carbon nanotubes in the horizontal direction.

14. A method as claimed in claim 13, wherein the catalyst pattern has one from a straight line shape, an intersection shape, a radial shape, a circular shape, and a rectangular shape, while the apertures are formed at intersecting areas of the catalyst pattern of a straight line shape, an intersection shape, and a radial shape, at an interior of a circle, and at an interior of a rectangular of the pattern.

15. A method as claimed in claim 14, wherein the carbon nanotubes formed respectively from the exposed surfaces of the catalyst pattern are grown to form a junction between them.

16. A method as claimed in claim 14, wherein the carbon nanotubes formed respectively from the exposed surfaces of the catalyst pattern intersect each other.

17. A method as claimed in claim 13, wherein the grown carbon nanotubes form a bridge construction, by which exposed surfaces of the catalyst pattern opposing each other are connected with each other.

18. A method as claimed in claim 13, wherein the grown carbon nanotubes form a free-hang construction, in which the carbon nanotubes from the exposed surfaces of the catalyst pattern opposing each other are separated from each other.

19. A method as claimed in claim 13, further comprising patterning a metal to intersect with at least one grown carbon nanotube to selectively form a junction between the at least one carbon nanotube and the metal at a specific location.

20. A method of horizontally growing carbon nanotubes, comprising:

forming a catalyst pattern in a predetermined two-dimensional arrangement on a first substrate;

fabricating a second substrate for preventing vertical growth of the carbon nanotubes and having holes in a predetermined arrangement;

placing the second substrate;

for preventing vertical growth of the carbon nanotubes over the first substrate having the catalyst pattern with a predetermined gap; and

synthesizing the carbon nanotubes at the catalyst pattern, so as to horizontally grow the nanotubes.

21. A method of horizontally growing carbon nanotubes, comprising:

forming a catalyst in a shape of nanodots or nanowires on a substrate;

patterning a growth preventing layer on the catalyst so as to prevent the nanodots or nanowires from growing in a vertical direction; and

selectively growing the carbon nanotubes in a horizontal direction at the nanodots or nanowires.

22. A method as claimed in claim 21, wherein the catalyst are patterned by an imprint method.

23. A method as claimed in claim 21, wherein the catalyst are patterned by a self-assembly method.

24. A method as claimed in claim 21, wherein the growth preventing layer includes an insulator film made from a compound selected from the group consisting of silicon nitride (SiN) and silicon oxide (SiO₂).

25. A method as claimed in claim 21, wherein the growth preventing layer includes a method selected from the group consisting of Palladium (Pd), Niobium (Nb), and Molybdenum (Mo).

26. A method of horizontally growing carbon nanotubes, comprising:

forming catalysts in a shape of nanowires on a substrate;

forming a growth preventing layer on the catalysts by a semiconductor process including a lithography process, the growth preventing layer being spaced from the substrate a predetermined gap;

eliminating a portion of the catalysts in an area at which the growth preventing layer is not formed by of a wet etching method; and

growing the carbon nanotubes in a horizontal direction between the catalysts formed under the growth preventing layer, by a chemical vapor deposition method.

27. A method as claimed in claim 26, wherein the catalyst are patterned by an imprint method.

28. A method as claimed in claim 26, wherein the catalyst are patterned by a self-assembly method.