Synthesis and Characterization of Self-Assembled Piezoelectric ZnO Nanostructures and Integration with Si Processing

Abstract

AbstractThe formation of 10 nm self-assembled ZnO nanoparticles on Si and SiO2/Si surfaces, using diblock copolymers, and wet chemical processing compatible with semiconductor manufacturing, is reported. The diblock copolymer, consisting of norbornene and a norbornenedicarboxcylic acid blocks with a 400 to 50 repeat unit ratio, was synthesized by ring opening metathesis polymerization. The microphase separation of the block copolymer was employed to grow spherical self-assembled ZnO nanoparticles The self-assembly of the inorganic nanoparticles was achieved at room temperature in the liquid phase by incorporating ZnCl2 to the carboxylic acid block, or by exposure of a solid film to diethyl zinc vapors. Subsequent room temperature wet chemical processing of the doped films resulted in the formation of zinc oxide, followed by the saturation of double bonds in the polymer backbone. The formation of ZnO was verified by x-ray photoelectron spectroscopy (XPS). Transmission electron microscopy (TEM ) micrographs show the size and distribution of the zinc oxide nanoclusters in the polymer matrix. This study provided information on the formation of zinc oxide structures in a self-assembled polymer matrix, with the intention of controlling the shape and distribution of zinc oxide domains. The doped diblock copolymer was applied on Si and SiO2/Si wafers, by standard spinon techniques, and its photolithographic patterning metalization was developed.