Nano-oxidation of silicon surfaces by noncontact atomic-force microscopy:: Size dependence on voltage and pulse duration

Local oxidation of silicon surfaces by noncontact atomic-force microscopy is an emerging and promising method for patterning surfaces at the nanometer scale due to its very precise control of the feature size. Here, we study the voltage and pulse duration conditions to generate a motive of a given height with the minimum lateral size. We find that for a fixed tip-sample separation, the combination of short pulses and relatively high voltages (similar to 20 V) produces the highest height:width ratio. The application of relatively high voltages produces a fast growth rate in the vertical direction while the lateral diffusion of oxyanions is inhibited for short pulses. The above results are applied to generate lines of tens of microns in length with an average width at half maximum of about 10 nm. (C) 2000 American Institute of Physics. [S0003-6951(00)04823-3].