Robust unipolar resistive switching of Co nano-dots embedded ZrO2 thin film memories and their switching mechanism

Abstract

The preparation and electrical properties of Ti/Co Embedded (Co-E) ZrO2/Pt resistive switching memories are investigated. The Co nano-dots are formed in ZrO2 thin film after the memory device is annealed at 600 °C in N2 ambient for 60 s without any chemical reaction between Co and ZrO2, which is confirmed from the transmission electron microscopy, energy dispersive X-ray analyzer, and X-ray photoelectron spectroscopy observations. The devices exhibit low forming voltage of −1.5∼−2.8 V and robust negative bias unipolar resistive switching behaviors with small negative set voltage of −1.1∼−1.6 V. A physical model based on a filament mechanism is employed to explain the switching behaviors. It has a high potential for ultra high density nonvolatile memory applications.