Interaction of PbTiO₃ Films with Si Substrate

Abstract

An investigation was made of the reasons why ferroelectric PbTiO 3 films are hard to grow on single-crystal Si substrates. PbTiO 3 films were formed on Si(100) and MgO(100) single-crystal substrates, and X-ray photoelectron spectroscopy (XPS) was used to analyze the composition, chemical structure and oxidation state at the interface between the substrate and the film. It was found that lead, oxygen and silicon diffused markedly at the interface and that the PbTiO 3 film experienced both a lead deficiency and Si diffusion. These phenomena are thought to be the reasons why it is difficult to form good PbTiO 3 films on silicon substrates by chemical vapor deposition (CVD). It was observed that the addition of TiO 2 and ZrO 2 films at the interface with the silicon substrate reduced the diffusion of Si to the PbTiO 3 film.