The characteristic O diffusion in the HfO2/SiO2/Si structure during annealing in O was investigated by using high-resolution Rutherford back-scattering spectroscopy combined with O-isotope substitution at 900C in 0.1Torr 18O2. The observed 18O profiles suggested that O molecules decomposed into atomic O in the HfO2 layer and diffused through the oxide layer via an exchange mechanism. This suggestion was supported by the observed activation energy (about 0.6eV) for the growth of the interfacial SiO2 layer.

Isotopic Labeling Study of the Oxygen Diffusion in HfO2/SiO2/Si. M.Zhao, K.Nakajima, M.Suzuki, K.Kimura, M.Uematsu, K.Torii, S.Kamiyama, Y.Nara, H.Watanabe, K.Shiraishi, T.Chikyow, K.Yamada: Applied Physics Letters, 2007, 90[13], 133510 (3pp)