Abstract
Using an Si(111) surface with atomically flat, wide terraces, the topographic change of SiO2/Si interfaces during thermal oxidation was investigated at an oxidation temperature of 1050°C using an atomic force microscope. Vestiges of two-dimensional oxide-island growth were observed at the interface. Then, a histogram for roughness height distribution based on atomic force microscope (AFM) data was plotted in order to evaluate the roughness within the terraces at the interface instead of the root mean square (RMS). This method revealed that the SiO2/Si interface consists of at least three layers separated from one another by 0.3 nm. This result provides evidence of the layer-by-layer model breaking down at the SiO2/Si interfaces.