Solution-based fabrication of high-κ dielectric nanofilms using titania nanosheets as a building block

We have demonstrated a novel procedure for fabricating high-kappa dielectric nanofilms by using a titania nanosheet as a building block. The layer-by-layer assembly of titania nanosheets using an atomically flat SrRuO3 substrate is advantageous as a means of fabricating atomically uniform multilayer high-kappa nanofilms. High-resolution transmission electron microscopy revealed that these multilayer nanofilms are composed of a well-ordered lamellar structure without an interfacial dead layer. These nanofilms exhibited both high dielectric constant (epsilon(r)similar to 125) and low leakage current density (J < 10(-7) A/cm(2)) even for thicknesses as low as 10nm. These results indicate that the titania nanosheet is a very promising candidate as a high-kappa nanoblock, and its bottom-up fabrication provides new opportunities for the development of high-kappa devices.