Nano-oxidation of an amorphous silicon surface with an atomic force microscope

A surface anodization technique was applied to an amorphous silicon (a-Si) surface by means of an atomic force microscope (AFM). The oxide line height increased with increasing applied voltage. The height of these lines on the un-hydrogenated amorphous silicon (a-Si:H) film was greater than that on crystalline silicon (c-Si) due to the large defect density in the former. Although the height of the oxide lines did not depend on film thickness, their width increased with decreasing film thickness. The photoluminescence (PL) intensity of the nano-scale lattice pattern drawn on a-Si:H was measured by micro-scale PL equipment. The PL intensity from the area having narrow oxide lines was smaller than that from the non-oxidized area. This indicates that anodization affects not only the area observed by the AFM, but its effects also spread over a sub-micron region.