Non-stoichiometric WO3−x-based nanoscale memristor for high-density memory

This work demonstrates forming-free and self-limiting resistive switching characteristics of non-stoichiometric WO3−x-based nanoscale devices without using any selector layer. Pt/W/WO3−x/Pt cross point and crossbar devices with individual cell dimensions of 200 × 400 nm2 have been fabricated using e-beam lithography, sputtering, and lift-off processes. The devices exhibited stable multi-level bipolar resistive switching with a high on/off ratio. In the crossbar device, the programmed resistance states were clearly distinguishable in the worst-case and arbitrary-case scenarios. The present study demonstrates that CMOS process-compatible WO3−x possesses great potential for designing future nanoscale resistive random access memories for high-density memory applications.