Improved Resistive Switching Reliability in Graded NiO Multilayer for Resistive Nonvolatile Memory Devices

An alternative approach of controlling bistable resistance switching in NiO was investigated. By fabricating a multilayer structure of three NiOx layers with varying oxygen content, bistable resistance switching could be localized. By varying the enveloping oxygen partial pressure during NiOx layer deposition from 10% to 30%, improved resistance and switching voltage distribution from cycle to cycle was achieved. In addition, more localized switching could emulate sub-100-nm-sized cells showing decreased reset current values on the order of 100 A. X-ray photon spectroscopy analysis shows a clear grading near the interfaces of successive NiO layers.