Non-volatile resistive switching in CuBi-based conductive bridge random access memory device

Abstract

Resistive switching devices, which are dominated by metal cation based conductive filament formation/rupture, are called programmable memory, or conductive bridge random access memory (CBRAM), and are widely expected to replace existing memory devices. In this letter, CuBi alloy was used as an active electrode to control the over-diffusion of Cu ions into the solid electrolyte of a CBRAM. In addition, resistive switching performance was improved by inserting lutetium and dysprosium metals, which acted as a buffer layer at the interface of the active electrode (CuBi) and the dielectric layer (Al2O3). When optimized, the Cu0.55Bi0.45/Lu(Dy)/Al2O3/Pt showed excellent resistive switching performance. This improvement can be explained by the high controllability of Cu in Cu-Bi electrode with the Lu (Dy) buffer layer. The formation of intermediate oxide buffer layers at the CuBi/Lu(Dy) interface was analysed using XPS. Moreover, conductive-atomic force microscope measurements helped to define the inverted cone shape of the metallic conductive filament. Published by AIP Publishing.