Oxidation process of HfO/sub 2//SiO/sub 2//Si structures observed by high-resolution RBS

Oxidation process of HfO
₂
/SiO
₂
/Si(001) structures during annealing in dry oxygen is studied by high-resolution Rutherford backscattering spectroscopy. During the growth of the interfacial SiO
₂
layer, surface accumulation of Si is observed. This indicates that silicon species are emitted from the SiO
₂
/Si interface to release the stress induced by oxidation as was predicted by recent theoretical studies. The behavior of oxygen during the growth of the interfacial SiO
₂
layer is also studied using 180 as a tracer. The observed 180 profile shows that atomic oxygen ions diffuse through HfO
₂
and SiO
₂
layers via an exchange mechanism