Tailoring the switching performance of resistive switching SrTiO₃ devices by SrO interface engineering

Redox-based resistive switching is one of the most-promising concepts in the focus of research to meet the ever-growing demand for faster and smaller non-volatile memory devices. In this work we present detailed studies of the impact of cation stoichiometry and surface segregation effects on the performance of the valence change memory model material SrTiO₃. In order to clarify if the enhanced switching performance of Sr-rich SrTiO₃ devices can be attributed to SrO segregation or to the formation of Sr-rich extended defects, we artificially engineered the formation of SrO islands by depositing additional SrO on top of stoichiometric SrTiO₃. We thereby unravel that the enhanced switching performance is solely accounted for by the formation of SrO islands and not influenced by extended defects. Consequently following our findings, we design devices with a further improved retention by tailoring the amount of SrO on the surface.