Utilizing compliance current level for controllability of resistive switching in nickel oxide thin films for resistive random-access memory

Abstract In this paper, we investigate two different resistive switching mechanisms in sputtered nickel oxide thin film which result from using the forming compliances of 15 μA and 15 mA. X-ray photoelectron spectroscopy material analysis results verify the nickel and oxygen chemical shifts, while energy-dispersive X-ray spectroscopy results confirm oxygen content changes after the forming process. Moreover, two markedly different resistive switching mechanisms, those of unipolar and bipolar, are accomplished in a single nickel oxide thin film. To clarify the two resistance switching mechanisms in the Pt/NiO/TiN device, a size effect measurement was conducted to determine the filament-type conduction. Moreover, the device capability to act as a memory device utilizing these two switching behaviors was determined, and a retention test for reliability was also carried out over 125 °C. Finally, the switching mechanism was confirmed by current fitting and sampling reset methods, and an appropriate physical model is presented. We anticipate this model can provide an insight into further future applications of RRAM devices.