Nanostructure and Ferroelectric Properties of Sol-Gel SBTN-Films for Electronic Devices

Abstract

The great problem for ferroelectric capacitors is the physico-chemical and mechanical interaction of ferroelectric films with surrounding materials, which leads to degrading of the characteristics of the ferroelectric element, increasing of current leakage and degradation of the transistor structures. Nanostructured ferroelectric films with the general formula SrBi₂ (TaxNb1-x)₂O₉ (SBTN-films) were obtained by sol-gel method and their properties were investigated. We demonstrated than the above-mentioned interaction depends not only on the external parameters, but also on the nanostructural properties of the ferroelectric. A content of niobium of 10 wt.% has the best suited for improving the structure and ferroelectric properties. In such case, grains of a quasispherical shape (95 (± 3 nm)) were detected, with a maximum residual polarization (7.9 μC/cm²), a maximum perovskite phase content (86%), and small sub-roughness (11 nm). Most probably, using materials with 10 wt.% Nb are a good candidate for elements of nonvolatile memory, more effectively than the SBT films. obtain coatings by electron-beam sputtering have been developed and synthesized by a sol-gel method based on a target of SiO₂, TiO₂, ZrO₂.