Effect of ITO electrode on conductance quantization and multi-level cells in TiN/SiOx/ITO devices

In this work, we study TiN/SiOx/ITO devices to implement conductance quantization and multilevel conductance for high-density memory applications. We observed stepwise conductance with integer and half-integer multiples under pulse and DC voltages. We predict this device's conductance quantization to be a combined result of the formation and rupture of oxygen vacancies in SiOx film and the formation of O2−rich ITO layers due to the oxidation reaction between ITO and SiOx. Furthermore, it was found that TiN/SiOx/ITO RRAM devices could stably endure each conductance level.