ABSTRACT
This chapter describes local anodic oxidation (LAO) on III-V semiconductor surfaces with the help of an atomic force microscope, and regular arrays of oxide dots are created by applying a voltage in the range 10–20 V to a conducting tip. A semiconductor surface can be oxidised locally by applying a negative bias to the nearby tip of a scanning probe microscope (SPM). The oxide is formed in an anodisation process using adsorbed water as the electrolyte. Negatively charged oxidising ions are created at the SPM probe; the electric field between the probe and the substrate enhances their diffusion into the surface. LAO has successfully been demonstrated on a variety of materials including silicon and A1GaAs heterostructures. The majority of the work was done on GaSb and lnAs grown on GaAs using metal-organic vapour phase epitaxy. A small number of experiments were performed on unprocessed lnAs and GaAs wafers.
