Investigating the switching dynamics and multilevel capability of bipolar metal oxide resistive switching memory

HfO x / AlO x bilayer resistive switching devices were fabricated for the study of the switching dynamics of the metal oxide memory. An exponential voltage-time relationship was experimentally observed as follows: the programming pulse widths need for switching exponentially decreased with the increase in the programming pulse amplitudes. Two following programming schemes were proposed to modulate the high resistance state values: (1) exponentially increase the programming pulse width; (2) linearly increase the programming pulse amplitude. Although both of these schemes were effective to achieve the target resistance, the transient current response measurements suggest the second scheme consumes considerably less energy in the programming. A field-driven oxygen ions migration model was utilized to elucidate the above experimentally observed phenomenon.