Controlled Polarizability of One-Nanometer-Thick Oxide Nanosheets for Tailored, High-κ Nanodielectrics

An important challenge in current microelectronics research is the development of techniques for making smaller, higher-performance electronic components. In this context, the fabrication and integration of ultrathin high-kappa dielectrics with good insulating properties is an important issue. Here, we report on a rational approach to produce high-performance nanodielectrics using one-nanometer-thick oxide nanosheets as a building block. In titano niobate nanosheets (TiNbO5, Ti2NbO7, Ti5NbO14), the octahedral distortion inherent to site-engineering by Nb incorporation results in a giant molecular polarizability, and their multilayer nanofilms exhibit a high dielectric constant (160-320), the largest value seen so far in high-kappa nanofilms with thickness down to 10 nm. Furthermore, these superior high-kappa properties are fairly temperature-independent with low leakage-current density (< 10(-7) A cm(-2)). This work may provide a new recipe for designing nanodielectrics desirable for practical high-kappa devices.