Resistive switching characteristics of nickel silicide layer embedded HfO_2 film

摘要

Resistive switching behavior of the Ti/HfO_2:NiSi:HfO_2/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 HfO_2 and silicide layer. Significant decrease of forming voltage is observed for the 550 ℃, 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 (>10~2), long retention more than 10~4s, and reasonable endurance (>10~3 cycles). A conducting filament model based on two stacks structure is employed to well explain the switching behaviors.