Solution-Based Fabrication of High-k Dielectrics Using Oxide Nanosheets

Abstract

We report a novel procedure for fabricating high-k dielectric nanofilms by using titania nanosheet as a building block. Langmuir-Blodgett deposition using atomically flat SrRuO3 or Pt substrates is advantageous as a means of fabricating atomically uniform multilayer high-k 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 (~125) and low leakage current density (J < 10-7 A/cm2) even for thicknesses as low as 10 nm. These results indicate that titania nanosheet is a very promising candidate as a high-k nanoblock, and its bottom-up fabrication provides new opportunities for the development of high-k devices.