Excellent State Stability of Cu/SiC/Pt Programmable Metallization Cells for Nonvolatile Memory Applications

We have investigated silicon carbide (SiC) as a new programmable metallization cell material for nonvolatile memory applications. Our Cu/SiC/Pt devices showed bipolar resistive switching; the conduction mechanisms can be explained by the formation of a Cu filament and Poole-Frenkel emission in the low-resistance and high-resistance states, respectively. In particular, our devices showed excellent state stability, e.g., nondestructive readout at various stress voltages, excellent retention characteristics at 150°C for 10⁴ s, and stable memory operation at high ambient temperature. We attribute this state stability to the SiC´s high chemical stability and the ability to act as a Cu diffusion barrier.