Elucidating the origin of resistive switching in ultrathin hafnium oxides through high spatial resolution tools

A new generation of non-volatile memories that store information in a metal/insulator/metal cell with switchable electrical resistance is gaining attention due to its simple structure and high yield. Despite extensive device level measurements have been performed, the origin of the resistive switching remains unclear. In this work, we use a disruptive approach to characterize cyclic resistivity changes at the nanoscale, combining a standard conductive atomic force microscope and a semiconductor parameter analyzer. Using this setup, we are able to assess the origin of resistive switching in Hafnium-based oxides, which takes place at the grain boundaries of polycrystalline stacks, and further calculations corroborate the local nature of this phenomenon.