Electric Formation of Metal/SrTiO3 Junctions and its Correlation to Multi-Dimensional Defects

Regarding the successful use of strontium titanate with different doping within resistive switching memory cells, the presence of crystallographic defects seems to be an important prerequisite. Standard explanations for resistive switching rely on the redistribution of oxygen vacancies, however, this motion can be enhanced or prevented by higher-dimensional defects. Intrinsic defects in crystalline SrTiO3 include point defects such as oxygen or strontium vacancies, line defects, stacking faults like Ruddlesden-Popper phases and precipitates (TiO2, SrO etc.). Electric formation of the metal/oxide/metal cells is widely used as an initial step to enable resistive switching, but the interaction of the multi-dimensional defects during this treatment remains questionable. This talk will present several measurements that were performed in situ, i.e. during the application of an electric field, to investigate the effects of the electric formation on the real structure.