Metal Assisted Chemical Etching
This process can produce arrays of nanowires, trenches and other 3D structures directly in silicon. Thin metal micro-nanoscale patterns generated via the Center's electrochemical S4 process or other nanoscale processes serve as a catalytic mask for this directional hydrofluoric acid wet etch process which can produce high aspect ratio micro/nano silicon structures (wires and trenches). Where the metal pattern contacts the Si substrate, it selectively catalyzes the etching process. Large area arrays of nanowires can be effectively and economically produced with "tuned" characteristics (diameter, spacing, length, and geometry).
Nanowires produced via this process can be further processed with a controlled sidewall surface roughening processes to create high-k nano wires which have potential application in thermoelectric devices.
For more information, download the full description.