It was recalled that interfacial O diffusion from high-permittivity gate dielectrics (ZrO2 and HfO2) into Si substrates in ultra large-scale integrated circuits had to be suppressed in order to prevent the formation of interfacial layers between the dielectrics and the Si substrates. The O diffusion was analyzed here by using a molecular dynamics technique that included many-body interactions and charge transfer between different elements. The results showed that the addition of Ti was effective in suppressing interfacial O diffusion. The results also showed that diffusion at the ZrO2/Si(111) and HfO2/Si(111) interfaces was much more suppressed than was diffusion at the ZrO2/Si(001) and HfO2/Si(001) interfaces.

Molecular-Dynamics Analysis of Interfacial Diffusion between High-Permittivity Gate Dielectrics and Silicon Substrates. T.Iwasaki: Journal of Materials Research, 2004, 19[4], 1197-202