Characteristics of HfO2/Hf-based bipolar resistive memories

Nano-scale Hf/Hf O2-based resistive random-access-memory(RRAM) devices were fabricated. The cross-over between top and bottom electrodes of RRAM forms the metal–insulator–metal sandwich structure. The electrical responses of RRAM are studied in detail, including forming process, SET process and RESET process.The correlations between SET voltage and RESET voltage, high resistance state and low resistance state are discussed. The electrical characteristics of RRAM are in a strong relationship with the compliance current in the SET process. The conduction mechanism of nano-scale Hf/Hf O2-based RRAM can be explained by the quantum point contact model.