부산대학교 도서관

We fabricated Au-doped and non-doped HfOx ReRAM device and investigated conductance change property under DC pulses. Au-doped device exhibited a hysteresis loop in a voltage sweep mode and a gradual conductance change under a train of DC voltage pulses, which is beneficial for artificial synapse. We assumed relaxation of conductance during pulse off time. The estimation based on this model well fits to the experimental results. Au doping has increased the number of oxygen vacancies in the HfOx layer due to spontaneous oxidation of Au atoms. Then oxygen ion diffusion in the Hf oxide layer is enhanced under the electric field. On the other hand, back flow of oxygen ion occurs during voltage off time due to concentration gradient of oxygen ions, resulting in the relaxation of conductance.