Integration of ferroelectric lead titanate nanoislands for direct hysteresis measurements

We report on the integration of fully functional ferroelectric PbTiO3 nanostructures of typically less than 100 nm lateral extension into a low-k dielectric hydrogen silsesquioxane film. Chemical mechanical polishing of the dielectric layer down to an overall thickness below the nanoparticles height exposes the structures. After confirmation of the piezoelectricity of individual embedded grains, gold electrode pads are deposited to characterize several of these grains in parallel. Evidence of ferroelectric switching is observed and discussed within an equivalent circuit model. This paves the way to a better integration and statistical analysis of ferroelectric nanostructures. (C) 2005 American Institute of Physics

Self-assembly of diblock-copolymer micelles for template based preparation of PbTiO3 nanograins

A bottom-up fabrication route for PbTiO3 nanograins grown on predefined TiO2 nanostructures used as seeds is presented. The structuring of the TiO2 sees is performed using a self-organized template constructed from a gold-loaded micellar monofilm. With this fabrication process, TiO2 seeds and PbTiO3 grains with diameters of 12 and 30 nm, respectively, are prepared without the need for electron beam lithography. The dimensions of the structure imposed by the micellar template are transferred through all the processing steps to the final PbTiO3 grains. Furthermore it is shown that the intermicelle distance and the degree of order in the dried monofilm is mainly determined by the preparation conditions, such as the pulling velocity in the dipping process and the strength of the surface-micelle interaction,and not necessarily by the architectural properties (block length and ratio) of the diblock copolymers that build the micelles. The intermicelle spacing in the dried films is much smaller than the micelle dimensions in solution, and approaches the dimensions of a fully collapsed micelle when the dipping process is performed slowly enough