Complementary Resistive Switching in Niobium Oxide-Based Resistive Memory Devices

For the applications of resistive random access memory (RRAM), we study the complementary resistive switch (CRS) behavior of a bilayer Nb₂O_5-∞/NbOy RRAM. The CRS effect is explained by the redistribution of oxygen vacancies inside the two niobium oxide layers. Improved CRS effects were observed using W top electrode (TE) instead of Pt, which can be attributed to the oxygen barrier layer derived from a self-formed WO_∞ layer between the W TE and the Nb₂O_5-∞ oxide film. The niobium oxide-based CRS devices within a single memory cell can be directly integrated into a crossbar memory array without the need of extra diodes; this can significantly reduce the fabrication complexity.