Resistive switching characteristics of nickel silicide layer embedded HfO2 film

Resistive switching behavior of the Ti/HfO2:NiSi:HfO2/Pt memory structure is investigated. Auger electron spectroscopy analysis indicates no metal diffusion from the electrodes and silicide layer on high-k film. Cross-sectional transmission electron microscopic micrographs revealed the thicknesses of the HfO2 and silicide layer. Significant decrease of forming voltage is observed for the 550 °C, 1 min annealed device embedded with nickel silicide (NiSi) layers. Entire device shows bipolar switching properties with very low set/reset voltage. The optimized annealed device with NiSi embedded layer exhibits improved memory performances such as good on/off ratio (>102), long retention more than 104 s, and reasonable endurance (>103 cycles). A conducting filament model based on two stacks structure is employed to well explain the switching behaviors.