Atomic-scale structure of SiO2/Si interface formed by furnace oxidation

SiO2/Si interfaces formed by furnace oxidation are investigated by scanning reflection electron microscopy (SREM). SREM observations reveal that the i nitial atomic steps on the Si(111)-7 x 7 and Si(001)-2 x 1 surfaces are pre served at the SiO2/Si interfaces and the interfacial atomic steps do not mo ve laterally during furnace oxidation. A profile analysis of reflection hig h-energy electron diffraction indicates that the atomic-scale roughness at the SiO2/Si interfaces is formed by furnace oxidation. The respective SiO2/ Si(111) and SiO2/Si(001) interfaces are made up of about 5- and 3-nm-diam i slands. Our results indicate that the layer-by-layer oxidation caused by tw o-dimensional island nucleation progresses during furnace oxidation. [S0163 -1829(98)04543-3].