Isotopic labeling study of the oxygen diffusion in HfO2/SiO2/Si

The characteristic oxygen diffusion in HfO2∕SiO2∕Si structure during the annealing in oxygen has been investigated by high-resolution Rutherford backscattering spectroscopy in combination with oxygen isotope substitution at 900°C in 0.1Torr O218. The observed O18 profile suggests that oxygen molecules are decomposed into atomic oxygen in the HfO2 layer and diffuse through the oxide layer via exchange mechanism. This is also supported by the observed activation energy of ∼0.6eV for the growth of the interfacial SiO2 layer.