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-κ 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-κ nanofilms with thickness down to 10 nm. Furthermore, these superior high-κ 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-κ devices.