ScholarWorks@동국대학교

초록

This research reports on the control of short-term and long-term memory in transition metal oxides embedded with localized gold nanoparticles (Au-NPs). The HfTiOx/TiSiOx switching layer, after the orderly and uniform insertion of Au-NPs, demonstrates uniform cycle-to-cycle DC switching with an ON-OFF ratio >10. Stable low-resistance states (LRS) and high-resistance state (HRS) are maintained up to 10(4) s with multilevel memory characteristics due to the control of oxygen vacancy concentrations. The localized Au-NPs enhance the local electric field near the HfTiOx/Au-NP interface, forming controlled conductive filaments, while the high concentration of oxygen vacancies creates a permanent conduction path inside TiSiOx after the electroforming process. The ITO/HfTiOx/Au-NP/TiSiOx/TaN memristor exhibits stable, controllable gradual bipolar switching and mimics several biological memory functions, including pulse-width-dependent plasticity, spike-timing-dependent plasticity, pulse-frequency-dependent plasticity, and experience-dependent plasticity. Additionally, a performance of 50k SET/RESET cycles without any significant degradation is achieved and the facilitation of long-term potentiation/depression are demonstrated. With the help of controlled oxygen vacancy generation on the surface of Au-NP inside the HfTiOx/TiSiOx switching layer, the memristor can emulate metaplasticity. Evaluation of a reservoir computing system utilizing the volatile switching of the memristor shows efficient processing of temporal data information which is essential for neuromorphic systems.

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