Observation of bias-dependent noise sources in a TiOx/TiOy bipolar resistive switching frame

Abstract

We report the conduction features associated with the evolution of oxygen ions (or vacancies) under bias for a TiOx (oxygen ion-rich)/TiOy (oxygen ion-deficient) bi-layer cell by identifying low-frequency noise sources. It is believed that a low resistance state enhances the formation of conductive filaments exchanging electrons through a nearest-neighbor hopping process, while a high resistance state (HRS) emphasizes the rupture of conductive filaments inside the insulating TiOx layer and a reduction/oxidation reaction at the oxide interfaces. The high resolution transmission electron microscope images of as-grown and HRS cells are also discussed.