Simple method to fabricate nano-porous diamond membranes
A method to fabricate nanoporous diamond membranes and a nanoporous diamond membrane are provided. A silicon substrate is provided and an optical lithography is used to produce metal dots on the silicon substrate with a predefined spacing between the dots. Selective seeding of the silicon wafer with nanodiamond solution in water is performed followed by controlled lateral diamond film growth producing the nanoporous diamond membrane. Back etching of the under laying silicon is performed to open nanopores in the produced nanoporous diamond membrane.
1. A method to fabricate nanoporous diamond membranes comprising the steps of:
providing a silicon substrate;
producing patterned metal dots on said silicon substrate with a predefined spacing between the patterned metal dots;
providing selective seeding of said patterned metal dots on said silicon substrate with a nanodiamond solution in water with controlled lateral diamond film growth producing a nanoporous diamond membrane; and
etching of the under laying silicon to open nanopores in the produced nanoporous diamond membrane.
2. The method to fabricate nanoporous diamond membranes as recited in claim 1 wherein producing patterned metal dots on said silicon substrate with said predefined spacing between the patterned metal dots includes using an optical lithography.
3. The method to fabricate nanoporous diamond membranes as recited in claim 1 wherein producing patterned metal dots on said silicon substrate with said predefined spacing between the patterned metal dots includes a laser write to produce submicron sized metal dots.
4. The method to fabricate nanoporous diamond membranes as recited in claim 1 wherein nanodiamond grain size in water solution used for the selective seeding is provided in the range of approximately 4-5 nm.
5. The method to fabricate nanoporous diamond membranes as recited in claim 1 wherein producing patterned metal dots includes producing patterned carbide forming metal layer.
6. The method to fabricate nanoporous diamond membranes as recited in claim 1 wherein said carbide forming metal layer is a selected one of Tungsten (W), Titanium (Ti), Tantalum (Ta), and Molybdenum (Mo).
7. The method to fabricate nanoporous diamond membranes as recited in claim 1 wherein said nanopores having a pore diameter in a range between about 30 nm and 70 nm.
8. The method to fabricate nanoporous diamond membranes as recited in claim 1 wherein etching of the under laying silicon to open said nanopores in the produced nanoporous diamond membrane includes using KOH.
9. The method to fabricate nanoporous diamond membranes as recited in claim 1 wherein providing selective seeding of said patterned metal dots on said silicon substrate with said nanodiamond solution in water with controlled lateral diamond film growth producing a nanoporous diamond membrane includes using said nanodiamond solution in deionized water.
10. The method to fabricate nanoporous diamond membranes as recited in claim 9 includes using a detonated nanodiamond solution.
11. The method to fabricate nanoporous diamond membranes as recited in claim 9 includes using a chemical vapor deposition (CVD) process.
12. The method to fabricate nanoporous diamond membranes as recited in claim 9 includes an ultrasonication seeding process.
13. The method to fabricate nanoporous diamond membranes as recited in claim 12 wherein said ultrasonication seeding process includes ultrasonication for a set time period.
14. The method to fabricate nanoporous diamond membranes as recited in claim 12 wherein said set time period of said ultrasonication seeding process is provided in a range between 10 minutes and 15 minutes.
15. The method to fabricate nanoporous diamond membranes as recited in claim 12 wherein said ultrasonication seeding process is followed by rinsing in deionized water.
16. The method to fabricate nanoporous diamond membranes as recited in claim 15 includes nitrogen (N 2 ) blow dry cleaning.