Multilevel and long retentive resistive switching in low temperature nanostructured Cu/SiOx-W-SiOx/Pt

Amorphous SiOx-based memory films are fabricated at room temperature, and study on their resistive switching characteristics and improvement approaches is performed. Multilevel resistive states with large ratio 1: ∼102: 3 × 105 and long retention exceeding 2 × 106 s at ambient temperature and humidity are observed in Cu/SiOx (9 nm)-W (∼2 nm)-SiOx (9 nm)/Pt ultrathin stack. Nonvolatile switching is consistently realized in microscopy. Based on investigations of microscopic conduction and microstructure, tungsten incorporation with copper as relay bridges for conducting filaments is proposed to attribute to the performance improvement and the multilevel switching mechanism