Metal-coated porous polymeric stamp materials for electrochemical imprinting
A metal-assisted chemical imprinting stamp includes a porous polymer substrate and a noble metal coating formed directly on the porous polymer substrate. Fabricating the metal-assisted chemical imprinting stamp includes providing a porous polymer substrate, and disposing a noble metal on the porous polymer substrate. Metal-assisted chemical imprinting includes positioning a silicon substrate in an etching solution, contacting a surface of the silicon substrate with a stamp comprising a noble metal layer on a surface of a porous polymer substrate, and separating the silicon substrate from the stamp to yield a pattern corresponding to the noble metal layer on the silicon substrate.
1. A metal-assisted chemical imprinting stamp comprising:
a porous polymer substrate; and
a nonporous noble metal coating formed directly on the porous polymer substrate.
2. The stamp of claim 1 , wherein the porous polymer substrate is resistant to hydrofluoric acid and hydrogen peroxide.
3. The stamp of claim 1 , wherein the porous polymer substrate defines pores having a pore size between about 5 nm and about 50 nm.
4. The stamp of claim 3 , wherein the porous polymer substrate comprises polyethersulfone.
5. The stamp of claim 1 , wherein the porous polymer substrate defines pores having a pore size between about 100 nm and about 2 μm.
6. The stamp of claim 5 , wherein the porous polymer substrate comprises polyvinylidene fluoride.
7. The stamp of claim 1 , wherein the nonporous noble metal coating comprises gold or silver.
8. The stamp of claim 1 , wherein a thickness of the nonporous noble metal coating is in a range of about 10 nm to about 50 nm.
9. A method of fabricating the metal-assisted chemical imprinting stamp of claim 1 , the method comprising:
providing the porous polymer substrate; and
disposing the nonporous noble metal coating on the porous polymer substrate.
10. The method of claim 9 , wherein disposing the nonporous noble metal coating on the porous polymer substrate comprises sputtering the noble metal on the porous polymer substrate.
11. A method of metal-assisted chemical imprinting, the method comprising:
positioning a silicon substrate in an etching solution;
contacting a surface of the silicon substrate with the metal-assisted chemical imprinting stamp of claim 1 ; and
separating the silicon substrate from the stamp to yield a pattern corresponding to the nonporous noble metal coating on the silicon substrate.
12. The method of claim 11 , wherein the silicon substrate is a silicon wafer.
13. The method of claim 11 , wherein the nonporous noble metal layer coating comprises nanometer-scale features.
14. The method of claim 13 , wherein a thickness of the nonporous noble metal coating is in a range between about 10 nm and about 50 nm.
15. The method of claim 11 , wherein the porous polymer substrate defines pores having a pore size in a range from about 5 nm to about 2 μm.
16. The method of claim 11 , wherein the etching solution comprises an electrolyte.
17. The method of claim 16 , further comprising a counter electrode in contact with the etching solution.
18. The method of claim 17 , further comprising externally electrically biasing the nonporous noble metal coating against the electrolyte with the counter electrode.
19. The method of claim 18 , further comprising applying a constant voltage or constant current to the counter electrode.
20. The method of claim 19 , wherein the nonporous noble metal layer coating functions as a working electrode.
21. The stamp of claim 1 , wherein the porous polymer substrate comprises polysulfone, polypropylene, polyacrylonitrile, or polytetrafluoroethylene.