[en] Bipolar resistive switching characteristics of CeO_x layer on Si-based bottom electrodes (BE) are presented. Owing to the formation and the presence of a thin SiO₂ interfacial layer (SiO₂-IL) between the CeO_x layer and BE, the set process is triggered by a local breakdown at the thin SiO₂-IL due to large differences in dielectric constants. Reset process, on the other hand, is obtained by local anodic oxidation to the breakdown spots by the high oxygen ion conductivity of the CeO_x layer. High insulating properties of SiO₂-IL enables obtaining a resistance ratio of over 10⁵ at high-resistive-state to low-resistive-state. A model to explain the resistance ratio has been proposed using initial trap density of SiO₂-IL. Moreover, forming-free feature can be achieved with NiSi₂ BE. (paper)