Roughness Increase on Surface and Interface of SiO2 Grown on Atomically Flat Si(111) Terrace

From analysis of the surface and interface roughness Of SiO2 films, it was found that roughness increased on both the surface and the interface only in the initial oxidation stage, where the oxide is thinner than 10 nm. However, for thicker regions, the roughness increase tends to saturate. Using an atomically flat Si(111) terrace, such roughness increases of the surface and interface can be observed. In addition, the thickness of 10 nm was found to be a threshold at which the mode of oxide growth changes to linear growth from initially enhanced growth. By taking account of Si emission at the SiO2/Si interface, a model has been demonstrated to explain the surface roughening Of SiO2. (C) 2009 The Japan Society of Applied Physics