Experiment and modeling of dynamical hysteresis in thin film ferroelectrics

Dynamical hysteresis in thin film ferroelectrics (FE) is modeled by the multi-domain time-dependent Landau Khalatnikov theory based on nucleation limited switching. Thin film ferroelectrics are treated as an ensemble of elementary regions characterized by independent coercive voltage and permanent polarization assumed to be Gaussian distributions, due to the intrinsic randomness of the material. Simulation of multi domain based ferroelectrics reveals the effects of domain number and inhomogeneity of material on the polarization behaviors. Particularly a direct extraction for ferroelectric parameters as well as their distributions is proposed by comparison with experiment, which is very important to assess the performance limit of ferroelectric-based devices. Based on this approach, the frequency-dependent hysteresis loops in thin film HZO FE capacitors measured by triangular waveforms are successfully reproduced. The presented model provides a physical insight into understanding and analyzing the polarization dynamics in ferroelectric-based devices. (C) 2020 The Japan Society of Applied Physics.