Role of the anode material in the unipolar switching of TiN\NiO\Ni cells

Abstract

In this paper, we investigate the unipolar resistive-switching mechanism in TiN\NiO\Ni cells, whereby the NiO layer is deposited by metal-organic chemical vapor deposition. Irrespective of the cell size down to 80 nm, controlled unipolar switching is observed only on condition the Ni electrode is used as anode. Local elemental analyzes revealed enhanced oxygen concentration at the NiO\Ni interface after reset operation. Based on this result as well as on the quantum-mechanical modeling of the conduction for different resistance states, the reset switching is analyzed in terms of electrochemically assisted oxidation process of the conductive filament close to the Ni anode. Electrical switching results on various stack configurations confirm the major impact of the electrode materials on the reset performances, bringing important insights into the mechanisms involved in the unipolar switching of this system. Literature data are discussed on the basis of this learning, suggesting possible extension of these considerations to other oxide-based switching systems.