High aspect ratio nano-oxidation of silicon with noncontact atomic force microscopy

Abstract

We report the formation of high aspect ratio ∼0.3 (height/width) oxide features with noncontact mode atomic force microscopy assisted lithography. The process requires high humidity levels, series of short pulses <100 ns, high voltage level >25 V, a tip oscillation amplitude ∼20 nm, and feedback “on.” We also show that the application of a voltage at magnitude higher than a certain limit damages the surface.