The interface of epitaxial SrTiO3 on silicon: <i>in situ</i> and <i>ex situ</i> studies

Abstract

The formation of interfacial layers between silicon and the overgrown epitaxial SrTiO3 as a function of the growth temperature has been studied in detail using x-ray photoelectron spectroscopy and high-resolution transmission electron microscopy. Models for the chemical compositions and atomic bonding states have been established. With a good understanding of the mechanisms of the interfacial layer formations, the molecular-beam epitaxy growth process can be well controlled to form high-quality, single-crystalline oxide films, as well as a desired interface between the grown oxide and silicon substrate. The epitaxial relationship has been found to be SrTiO3 (001)∥Si(001), and SrTiO3 〈100〉∥Si〈110〉.