| 초록 |
Resistive memory, also called memristor, has a very simple structure compared to commercial memory, and is attracting attention for its fast operation speed and data storage capability. With this simple MIM(Metal-Insulator-Metal) structure, RRAM is a memory device expected to satisfy high density and power efficiency. For the explanation of the switching behavior of RRAM, it is known that it is important to determine what the conductive filament behaves. In the case of the Valence Change Mechanism (VCM), it is known that the conductive filaments consist of oxygen defects in the transition metal oxide. The phenomenon of connection and disconnection of conductive filaments is the most important part of resistive memory, but it is very difficult to observe in practical experiments. In this study, we propose a full cycle model by analyzing the movement, formation, and recombination of oxygen vacancy using finite element simulation. Electrical conductivity and thermal conductivity are determined by the phase variables formed by oxygen vacancy, and Forming, Reset, and Set states are shown according to these changes in conductivity. In addition, vacancies movement is modeled by thermal and drift diffusion equations as an fully-coupled model of electrical, thermal, and oxygen vacancies. As a result, the distribution of oxygen vacancies and I-V curves according to each state were compared and analyzed. |
