Nanometer scale patterning of silicon (100) surfaces by an atomic force microscope operating in air

Modification on silicon (100) surfaces was demonstrated by using an atomic force microscope operating in air. Field-enhanced oxidation on silicon surfaces with protection oxide was done locally by biasing a p-type heavily doped silicon tip between -3 and -10 V. Oxide lines of width as small as ∼10 nm were achieved. After a dip in aqueous HF solution, the oxide was etched away; the modification depth, ∼1 nm, was characterized by the same atomic force microscope. Other field induced reactions for patterning are possible.