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/HfOx/SiO2 asymmetric self-rectifying resistive switching device is fabricated. The interfacial defects in the HfOx/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.