Inorganic nanostructure reactive direct-write and growth
Methods for forming inorganic nanostructures are provided. The methods create the inorganic nanostructures by positioning a writing electrode (e.g., a conductive “stamp”) spaced nanometers above a substrate such that a precursor is intermediate the two. Applying an electric field, a voltage bias, an ionic current, or an electronic current between the writing electrode and the substrate converts the precursor into an inorganic solid material (e.g., a semiconductor such as silicon or germanium) in the area of the writing electrode.
1. A method of forming a pattern on a substrate, comprising the steps of:
(a) positioning a writing electrode within 500 nm of a substrate surface, wherein the substrate surface is selected from the group consisting of a conductive material, a semiconductive material, and an insulating material that is a thin film covering a conductive or semiconductive material;
wherein a precursor is disposed in contact with the substrate surface, the precursor having a composition configured to provide an inorganic solid material when subjected to an electric field of 10 7 V/m or greater; and
(b) applying an electric field of 10 7 V/m or greater between the substrate surface and the writing electrode, and thereby through the precursor, to provide a printed pattern of the inorganic solid material on the substrate.
2. The method of claim 1 , wherein the writing electrode is a stamp having a relief pattern formed from a conductive material facing the substrate surface, and wherein the printed pattern of the inorganic solid material has the shape of the relief pattern.
3. The method of claim 2 , wherein the stamp comprises a polymer substrate supporting the relief pattern.
4. The method of claim 3 , wherein the polymer substrate is polydimethylsiloxane.
5. The method of claim 2 , wherein the entire printed pattern is formed simultaneously.
6. The method of claim 1 , wherein the writing electrode is scanning-probe microscopy tip.
7. The method of claim 6 , wherein the printed pattern is formed by moving the scanning-probe microscopy tip while applying the electric field in the presence of the precursor.
8. The method of claim 6 , wherein a plurality of scanning-probe microscopy tips are used simultaneously to form the printed pattern.
9. The method of claim 1 , wherein the precursor is a precursor for an inorganic solid material selected from the group consisting of a metal, a semiconductor, and a dielectric.
10. The method of claim 1 , wherein the precursor is a precursor for a single inorganic semiconductor.
11. The method of claim 1 , wherein the precursor is a precursor for a compound inorganic semiconductor.
12. The method of claim 11 , wherein the precursor comprises a first precursor for a first inorganic semiconductor and a second precursor for a second inorganic semiconductor, and wherein the compound inorganic semiconductor formed on the substrate has a composition proportional to the amounts of the first precursor and the second precursor.
13. The method of claim 1 , wherein the precursor comprises one or more dopants that are incorporated into the inorganic solid material.
14. The method of claim 1 , wherein the precursor is selected from the group consisting of a liquid, a gas, a solid, and combinations thereof.
15. The method of claim 1 , wherein the precursor consists of inorganic compounds.
16. The method of claim 1 , wherein the precursor comprises inorganic and organic compounds, such that the inorganic solid includes organic compounds.
17. The method of claim 1 , wherein positioning the writing electrode comprises submerging the writing electrode in a solution of the precursor.
18. The method of claim 17 , wherein the solution of the precursor is contained in a fluid cell.
19. The method of claim 1 , wherein positioning the writing electrode comprises using a piezoelectric device to manipulate the writing electrode, the substrate, or both.
20. The method of claim 1 , wherein the semiconductive substrate or insulating surface is made conductive by shining light on it.
21. The method of claim 1 , wherein the writing electrode is configured to be integrated into a photolithography tool.
22. The method of claim 21 , wherein the photolithography tool is selected from the group consisting of an aligner, a stepper, and any other device that precisely positions the electrode and the substrate.
23. The method of claim 1 , wherein the writing electrode is in contact with the substrate surface.
24. The method of claim 1 , wherein the writing electrode is not in contact with the substrate surface.