A non-lithographic plasma nanoassembly technology for polymeric nanodot and silicon nanopillar fabrication

摘要

In this work,we present plasma etching alone as a directed assembly method to both create the nanodot pattern on an etched polymeric (PMMA) film and transfer it to a silicon substrate for the fabrication of silicon nanopillars or cone-like nanostructuring.By using a shield to control sputtering from inside the plasma reactor,the size and shape of the resulting nanodots can be better controlled by varying plasma parameters as the bias power.The effect of the shield on inhibitor deposition on the etched surfaces was investigated by time-of-flight secondary ion mass spectroscopy (ToF-SIMS) measurements.The fabrication of quasi-ordered PMMA nanodots of a diameter of 25 nm and period of 54 nm is demonstrated.Pattem transfer to the silicon substrate using the same plasma reactor was performed in two ways:(a) a mixed fluorine-fluorocarbon-oxygen nanoscale etch plasma process was employed to fabricate silicon nanopillars with a diameter of 25 nm and an aspect ratio of 5.6,which show the same periodicity as the nanodot pattern,and (b) high etch rate cryogenic plasma process was used for pattern transfer.The result is the nanostructuring of Si by high aspect ratio nanotip or nanocone-like features that show excellent antireflective properties.