Programmable nanometer-scale electrolytic metal deposition and depletion

• US 6,447,663 B1
• Filed: 10/24/2000
• Issued: 09/10/2002
• Est. Priority Date: 08/01/2000
• Status: Expired due to Fees

• Current Assignee: UT-Battelle LLC
• Original Assignee: UT-Battelle LLC
• Inventors: Lee, James Weifu, Greenbaum, Elias
• Primary Examiner(s): Nguyen, Nam
• Assistant Examiner(s): Leader, William T.
• Application Number:
  US09/694,978
• Time in Patent Office: 686 Days
• Field of Search: 205/81, 205/83, 205/104, 205/114, 205/115, 205/118, 205/122, 205/640, 205/641, 205/644, 205/645, 205/646
• US Class Current: 205/104
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C25D 21/12 Process control or regulation controlling or regulating in general G05
• CPC Class Codes: C25D 5/18 Electroplating using modulated, pulsed or reversing current
• CPC Class Codes: G11C 13/0002 using resistive RAM [RRAM] elements
• CPC Class Codes: Y10S 977/899 Electrolytic

Abstract

A method of nanometer-scale deposition of a metal onto a nanostructure includes the steps of: providing a substrate having thereon at least two electrically conductive nanostructures spaced no more than about 50 μm apart; and depositing metal on at least one of the nanostructures by electric field-directed, programmable, pulsed electrolytic metal deposition. Moreover, a method of nanometer-scale depletion of a metal from a nanostructure includes the steps of providing a substrate having thereon at least two electrically conductive nanostructures spaced no more than about 50 μm apart, at least one of the nanostructures having a metal disposed thereon; and depleting at least a portion of the metal from the nanostructure by electric field-directed, programmable, pulsed electrolytic metal depletion. A bypass circuit enables ultra-finely controlled deposition.

Claims

1. A method of nanometer-scale deposition of a metal onto a nanostructure comprising the steps of:

a. providing a substrate having thereon at least two electrically conductive nanostructures spaced no more than about 50 μ

m apart; and

b. depositing metal on at least one of said nanostructures by electric field-directed, programmable, pulsed electrolytic metal deposition.

2. A method in accordance with claim 1 wherein said metal is supplied through electrolytic reduction of at least one water-soluble metal compound.

3. A method in accordance with claim 2 wherein said water-soluble metal compound is selected from the group consisting of PtCl₄, OsCl₃, Na₂[PtCl₆], Na₂[OsCl₆], (NH₄)₂RUCl₆, K₃RuCl₆, Na₂PdCl₆, Na₂IrCl₆, (NH₄)₃IrCl₆, (NH₄)₃RhCl₆, K₂PdCl₄, (NH₄)₂PdCl₄, Pd(NH₃)₄Cl₂, ReCl₃, NiCl₂, CoCl₂, PtO₂, PtCl₂, Pt(NH₃)₄Cl₂, (NH₄)₆Mo₇O₂₄, NaAuCl₄, K₂[PtCl₄], and K₃Fe(CN)₆.

4. A method in accordance with claim 1 wherein said depositing step further comprises controlling the number of atoms deposited per pulse.

5. A method in accordance with claim 4 wherein said depositing step further comprises using a bypass circuit to further control the number of atoms deposited per pulse.

6. A method in accordance with claim 1 wherein at least one of said nanostructures further comprises a nanowire.

7. A method in accordance with claim 1 wherein at least one of said nanostructures further comprises a nanotube.

8. A method of nanometer-scale deposition of a metal onto a nanostructure comprising the steps of:

a. providing a substrate having thereon at least two nanostructures having opposing tips spaced no more than 10 μ

m apart so that an electric field is strongest between said tips to facilitate an electrolytic metal deposition reaction on at least one of said tips; and

b. depositing metal on at least one of said tips by precisely controlling the amount of electrolytic metal deposition using a programmable pulsed current source to control the number of electrons used in the electrolytic deposition reaction to achieve a deposition rate in the range of 100 to 10¹⁴ metal atoms per pulse.

9. A method in accordance with claim 8 wherein said metal is supplied through electrolytic reduction of at least one water-soluble metal compound.

10. A method in accordance with claim 9 wherein said water-soluble metal compound is selected from the group consisting of PtCl₄, OsCl₃, Na₂[PtCl₆], Na₂[OsCl₆], (NH₄)₂RUCl₆, K₃RuCl₆, Na₂PdCl₆, Na₂IrCl₆, (NH₄)₃IrCl₆, (NH₄)₃RhCl₆, K₂PdCl₄, (NH₄)₂PdCl₄, Pd(NH₃)₄Cl₂, ReCl₃, NiCl₂, CoCl₂, PtO₂, PtCl₂, Pt(NH₃)₄Cl₂, (NH₄)₆Mo₇O₂₄, NaAuCl₄, K₂[PtCl₄], and K₃Fe(CN)₆.

11. A method in accordance with claim 8 wherein a bypass circuit is used to further control the number of electrons used in the electrolytic deposition reaction to achieve a deposition rate in the range of 100 to 2500 metal atoms per pulse.

12. A method in accordance with claim 8 wherein at least one of said nanostructures further comprises a nanowire.

13. A method in accordance with claim 8 wherein at least one of said nanostructures further comprises a nanotube.

14. A method of nanometer-scale depletion of a metal from a nanostructure comprising the steps of:

a. providing a substrate having thereon at least two electrically conductive nanostructures spaced no more than about 50 μ

m apart, at least one of said nanostructures having a metal disposed thereon; and

b. depleting at least a portion of said metal from said nanostructure by electric field-directed, programmable, pulsed electrolytic metal depletion.

15. A method in accordance with claim 14 wherein said depleting step further comprises controlling the number of atoms depleted per pulse.

16. A method in accordance with claim 15 wherein said depleting step further comprises using a bypass circuit to further control the number of atoms depleted per pulse.

17. A method in accordance with claim 14 wherein at least one of said nanostructures further comprises a nanowire.

18. A method in accordance with claim 14 wherein at least one of said nanostructures further comprises a nanotube.

19. A method of nanometer-scale depletion of a metal to a nanostructure comprising the steps of:

a. providing a substrate having thereon at least two nanostructures having opposing tips spaced no more than 10 μ

m apart so that an electric field is strongest between said tips to facilitate an electrolytic metal depletion reaction from at least one of said tips, at least one of said tips having a metal disposed thereon; and

b. depleting at least a portion of said metal from said tip by precisely controlling the amount of electrolytic metal depletion using a programmable pulsed current source to control the number of electrons used in the electrolytic depletion reaction to achieve a depletion rate in the range of 100 to 10¹⁴ metal atoms per pulse.

20. A method in accordance with claim 19 wherein a bypass circuit is used to further control the number of electrons used in the electrolytic depletion reaction to achieve a depletion rate in the range of 100 to 2500 metal atoms per pulse.

21. A method in accordance with claim 19 wherein at least one of said nanostructures further comprises a nanowire.

22. A method in accordance with claim 19 wherein at least one of said nanostructures further comprises a nanotube.