Copper sulfide-based resistance change memory

Nonvolatile memories (NVMs) based on an instantaneous resistance change when an electric bias is applied are very attractive for future memory applications. Here, we report the fabrication and electrical characterization of mum-sized Cu₂S NVM devices. With stoichiometric Cu₂S films grown by anodic polarization, we can generate consistent and reproducible resistance switching devices. The fabricated devices exhibit large on/off ratio over 10⁵ with low switching voltages (below 0.3 V). On-resistance (R_on) value of 150 Omega does not change as the size of the devices shrinks. On the contrary, off-resistance (R_off) depends on the device area inversely, which enables the enhancement of on/off ratio with the scaling-down of the device.