Nano-analytical investigation of the forming process in an HfO2-based resistive switching memory

Metal oxide-based resistive random access memory devices are highly attractive candidates for next-generation nonvolatile memories, but the switching phenomena remain poorly understood. This article focuses on microscopic understanding of initial forming step, which is decisive process. The integrated effect in Ti/ HfO2/ TiWN metal insulator structures studied. After forming, transmission electron microscopy investigations pointed out presence a funnel-shaped region, ON state cell, where slightly oxidized Ti ( TiOx) was present within HfO2 dielectric. Modeling measured conductance cell with semi-classical approximation consistent conductive nanometric TiOx filament (or sum sub-nanometric filaments) region. area likely formed by diffusion after dielectric breakdown.