Method of fabricating free-form, high-aspect ratio components for high-current, high-speed microelectronics

1. A method of fabricating a three-dimensional microelectronic structure comprising:

passing a first precursor material for a selected three-dimensional microelectronic structure into a reaction chamber at temperatures sufficient to maintain said precursor material in a predominantly gaseous state;

maintaining said reaction chamber under sufficient pressures to enhance formation of a first portion of said three-dimensional microelectronic structure;

applying an electric field between an electrode and said microelectronic structure at a desired point under conditions whereat said first portion of a selected three-dimensional microelectronic structure is formed from said first precursor material;

positionally adjusting either said formed three-dimensional microelectronic structure or said electrode whereby further controlled growth of said three-dimensional microelectronic structure occurs;

passing a second precursor material for a selected three-dimensional microelectronic structure into a reaction chamber at temperatures sufficient to maintain said precursor material in a predominantly gaseous state;

maintaining said reaction chamber under sufficient pressures whereby a second portion of said three-dimensional microelectronic structure formation is enhanced;

applying an electric field between an electrode and said microelectronic structure at a desired point under conditions whereat said second portion of a selected three-dimensional microelectronic structure is formed from said second precursor material; and,

positionally adjusting either said formed three-dimensional microelectronic structure or said electrode whereby further controlled growth of said three-dimensional microelectronic structure occurs.

2. The method of claim 1 , wherein the second precursor material is passed into the reaction chamber in a manner which results in a gradient contact between the first precursor material and the second precursor material.

3. The method of claim 1 , wherein the second precursor material is passed into the reaction chamber in a manner which results in an ohmic contact between the first precursor material and the second precursor material.

4. The method of claim 1 , wherein the pressure is from about 0.01 atm to about 10 atm.

5. The method of claim 1 , wherein the electric field is applied to the microelectronic structures at a plurality of desired points in the reaction chamber by means of an array of electrodes, under conditions whereat a plurality of portions of one or more three-dimensional microelectronic structures is simultaneously formed.

6. The method of claim 1 , further comprising the step of heating the walls of the reaction chamber to a desired temperature prior to passing the first precursor material into the reaction chamber.

7. The method of claim 1 , wherein the first and the second precursor materials are passed into the reaction chamber by means of a nozzle.

8. The method of claim 1 , wherein the first precursor material and the second precursor material form a p-n junction having an abrupt contact.

9. The method of claim 1 , wherein the first precursor material and the second precursor material form a Schottky junction having an abrupt contact.

10. The method of claim 1 , further comprising adding a dielectric material between the first precursor material and the second precursor material.

11. The method of claim 1 , wherein the first precursor material and the second precursor material form an abrupt ohmic contact.

12. The method of claim 1 wherein said three-dimensional microelectronic structure is a diode.

13. The method of claim 1 , further comprising the step of evacuating the reaction chamber of the first precursor material prior to passing a second precursor material into the reaction chamber.

14. The method of claim 13 , further comprising the step of cleaning the tip of said three-dimensional microelectronic structure prior to passing a second precursor material into the reaction chamber.

15. The method of claim 1 , wherein the first precursor material is an n-doped semiconductor and the second precursor material is selected from the group consisting of a p-doped semiconductor, a metal, and combinations thereof.

16. The method of claim 15 , wherein the metal is selected from the group consisting of tungsten, molybdenum and combinations thereof.

17. The method of claim 1 , wherein the second precursor material is in contact with a substantial portion of the first precursor material.

18. The method of claim 17 , wherein at least one additional precursor material is in contact with a substantial portion of the second precursor material, to form a capacitor.

19. The method of claim 1 , further comprising:

(a) passing at least one additional precursor material for a selected three-dimensional microelectronic structure into a reaction chamber at temperatures sufficient to maintain said precursor material in a predominantly gaseous state;

(b) maintaining said reaction chamber under sufficient whereby at least one additional portion of said three-dimensional microelectronic structure formation is enhanced;

(c) applying an electric field between an electrode and said microelectronic structure under conditions whereat for said at least one additional portion of a selected three-dimensional microelectronic structure is formed from said at least one additional precursor material;

(d) positionally adjusting either said formed three-dimensional microelectronic structure or said electrode whereby further controlled growth of said three-dimensional microelectronic structure occurs; and,

(e) repeating steps (a)-(d) to form at least one three-dimensional microelectronic component.

20. The method of claim 19 , wherein the first precursor material forms a gradient contact with the second precursor material, and wherein the second precursor material forms a gradient contact with an additional precursor material which is the same as the first precursor material, to form a resistor.

21. The method of claim 19 wherein said three-dimensional microelectronic structure is a transistor.

22. The method of claim 19 , further comprising fabricating at least one additional three-dimensional microelectronic component, and electrically connecting the microelectronic components to form a functional, integrated electronic device.

23. The method of claim 22 , further comprising fabricating at least one additional functional integrated electronic device and electrically connecting the integrated electronic devices.