Phosphate Incorporation In Anodic Hafnium Oxide Memristors

The electrochemical fabrication of memristive devices based on Hf is demonstrated. Electrolyte incorporation in memristors is confirmed in oxides grown in 0.1, 0.5 and 1 M phosphate buffers. The impact of phosphate species on conductive filaments formation is described. The use of 1 M phosphate buffer allows formation of Hf-O-P compounds that hinder phosphate incorporation into the bulk of the memristors. Endurance, retention and memory characteristics of anodic Hf memristors suggest improved properties, as compared with previous reports, especially after mild heat treatments of devices. High resolution atomic imaging of conducting filaments allowed further understanding of memristive switching in HfO2.