High resolution electron microscopy studies of native oxide on silicon

High resolution electron microscopy (HREM) of cross-sectional specimens has shown that the thickness of the native oxide on silicon o is 20 ± 3A, independent of surface orientation. This result has con-o firmed the value 21 ,± 4A determined by ellipsometry assuming a stoichiometric Si02 native oxide. Previous reports of a nonstoichiometric transition layer between Si and Si02 containing an excess of 1015 cm-2 Si atoms have also been alternatively explained by the observed morphological features of the Si-Si02 interface.