Nano-size anodization of Si by using an atomic force microscope

Abstract

Nano meter-sized SiO2 lines have been formed on silicon (Si) surface by using AFM tip-induced anodization. A thin water film between the tip and the Si surface worked as a highly resistive electrolyte in a wet air atmosphere. The applied bias voltage dependence of widths and heights of the oxide lines was investigated. It was revealed that the Si was oxidized at very low bias, such as 2.2 V. The thinnest line width of 100 nm has been achieved. The carrier type and concentration were also important factors on the size control in the anodic oxidation.