Nanoscale Plasmon‐Enhanced Spectroscopy in Memristive Switches. Issue 10 (12th January 2016) - Di Martino, Giuliana
Abstract : Resistive switching memories are nonvolatile memory cells based on nano‐ionic redox processes and offer prospects for high scalability, ultrafast write and read access, and low power consumption. In two‐terminal cation based devices a nanoscale filament is formed in a switching material by metal ion migration from the anode to the cathode. However, the filament growth and dissolution mechanisms and the dynamics involved are still open questions, restricting device optimization. Here, a spectroscopic technique to optically characterize in situ the resistive switching effect is presented. Resistive switches arranged in a nanoparticle‐on‐mirror geometry are developed, exploiting the high sensitivity to morphological changes occurring in the tightly confined plasmonic hotspot within the switching material. The focus is on electrochemical metallization and the optical signatures detected over many cycles indicate incomplete removal of metal particles from the filament upon RESET and suggest that the filament can nucleate from different positions from cycle to cycle. The technique here is nondestructive and the measurements can be easily performed in tunable ambient conditions and with realistic cell geometries. Abstract : To optically probe in situ the nanofilament formation in memristive switches, a new technique is proposed. Plasmonic interactions around the filament to scatter light are exploited, which results in high sensitivity to morphological changes in the switching material. The findings indicate the incomplete removal of filament particles upon RESET and suggest that the filament nucleates from different positions from cycle to cycle.