Accurate analysis of conduction and resistive-switching mechanisms in double-layered resistive-switching memory devices

Resistive-switching and current conduction mechanisms have been studied in TiN/Ti/TiOx/HfOx/TiN resistive-switching random access memories (RRAMs). From I-V characteristics and temperature measurement, thermionic emission is found to be the most appropriate mechanism representing the dominant current conduction in all the bias regions and resistance states. Low-frequency noise power spectrum is measured to analyze accurately the conduction mechanism, which corroborates the thermionic-emission. Also, using the migration of oxygen ions depending on the polarity of the applied field, we propose the resistive-switching model of a double-layered RRAM to explain the unique resistive-switching characteristics.