Memcapacitive characteristics in reactive-metal (Mo, Al)/HfOX/n-Si structures through migration of oxygen by applied voltage

Memcapacitive characteristics were investigated in metal-oxide-semiconductor (MOS) structure of reactive electrode (Mo, Al) and hafnium oxide (HfOX) on n-type Si substrate. The capacitance-voltage curves exhibited sequentially changing capacitance with memory function as repeating voltage sweeps, featured the memcapacitive behaviors. The saturation capacitance was decreased by repeating +V sweeps, while barely changed by −V sweeps. Also, the capacitance-time curves disclosed the same tendency. However, the MOS structure with inert Pt electrode did not show the capacitance change. The memcapacitive behaviors were induced by the migration of oxygen ions from HfOX to reactive electrodes by applied voltage, which altered the permittivity of HfOX.