Modeling of cross-talk phenomena in thin film ferroelectric nanocapacitor arrays by finite element method combined with Monte Carlo calculations

摘要

In the last few years, the interest in developing ferroelectric systems with high recording density close to 1Tb/in.~2 has strongly increased. The ferroelectric thin films are subjected to the electric field applied by using nanocapacitors (diameters of ∼70 nm) containing a ferroelectric active material. In order to increase the memory density, the nanocapacitor dimensions and the distance between them have to be strongly decreased. However, if the lateral distance between the nanoelectrodes is reduced too much, a domain wall propagation from the nanocapacitor subjected to the voltage to the neighboring capacitors (so-called "cross talk") is observed. This phenomenon is undesired because the memory spatial resolution is affected. In the present paper, the role of the geometrical characteristics (electrode radius, lateral distance between the electrodes and the film thickness) is investigated, by using a combined Finite Element Method with the Monte Carlo model to describe the local switching properties. The distributions of the electrical potential and local fields were computed by using the Finite Element Method. After describing the conditions for the appearance of the "cross-talk" phenomenon in ferroelectric nanocapacitor systems, some valuable solutions to avoid it are presented.