Impact of Cationic Stoichiometry on Physical, Optical and Electrical Properties of SrTiO Thin Films Grown on (001)-Oriented Si Substrates.

In this study, we investigate the changes in the crystalline structure of MBE-deposited SrTiO layers on Si with different deviations from Sr/Ti stoichiometry as deposited but also after annealing at high temperatures (>600 °C). We show that as-grown 15 nm thick non-stochiometric SrTiO layers present surprisingly lower FWHM values of the (002) omega diffraction peak compared to fully stoichiometric layers of similar thickness. This can misleadingly point to superior crystalline quality of such non-stochiometric layers.