Atomic Scale Modulation of Self-Rectifying Resistive Switching by Interfacial Defects

Higher memory density and faster computational performance of resistive switching cells require reliable array-accessible architecture. However, selecting a designated cell within a crossbar array without interference from sneak path currents through neighboring cells is a general problem. Here, a highly doped n⁺⁺ Si as the bottom electrode with Ni-electrode/HfO_x/SiO₂ asymmetric self-rectifying resistive switching device is fabricated. The interfacial defects in the HfO_x/SiO₂ junction and n⁺⁺ Si substrate result in the reproducible rectifying behavior. In situ transmission electron microscopy is used to quantitatively study the properties of the morphology, chemistry, and dynamic nucleation–dissolution evolution of the chains of defects at the atomic scale. The spatial and temporal correlation between the concentration of oxygen vacancies and Ni-rich conductive filament modifies the resistive switching effect. This study has important implications at the array-level performance of high density resistive switching memories.