Long-term-retention characteristics of small inverted dots formed on congruent single-crystal LiTaO3

To investigate the long-term retention characteristics of a ferroelectric-data-storage system, 80-nm-thick congruent LiTaO3 plates with inverted-domain dot arrays composed of 100-nm-φdots were baked at 220, 250, 280, and 300°C. After heat treatment over a range of different time intervals, the dots shrank. From the change in the dot area density, the activation energy and frequency factor, parameters of the Arrhenius equation, were determined to be Ea=0.76eV and α=2.21×105, respectively. Using these parameters, lifetime length at 80°C was estimated to be more than 16yr and is sufficiently long compared with that of general memory devices.