We theoretically study an oxygen vacancy (V O) diffusion in Al 2O3-based resistive-random-access-memories (ReRAMs). We find that the activation energy of V O diffusion in Al2O3 strongly depends on the charge state of V O. In ReRAM, the charge state of V O can be easily changed by applying voltage and the lowest activation energy is observed at q = 2+. The operation voltage on Al2O3-based ReRAM is close to the activation energy at q = 2+, indicating that V O diffuses with doubly positive state. Moreover, the activation energy at q = 0 is close to that observed in bulk Al2O3, which explains the discrepancy between previous experimental and theoretical studies.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)