Highly Oriented Growth of Piezoelectric Thin Films on Silicon Using Two-Dimensional Nanosheets as Growth Template Layer

Minh D. Nguyen,Huiyu Yuan, Evert P. Houwman, Matthijn Dekkers, Gertjan Koster, Johan E. ten Elshof, and Guus Rijnders
ACS Appl. Mater. Interfaces, Article ASAP, Publication Date (Web): October 26, 2016 (2016)

Ca2Nb3O10 (CNOns) and Ti0.87O2 (TiOns) metal oxide nanosheets (ns) are used as a buffer layer for epitaxial growth of piezoelectric capacitor stacks on Si and Pt/Ti/SiO2/Si (Pt/Si) substrates. Highly (001)- and (110)-oriented Pulsed Laser Deposited PZT films are achieved by utilizing CNOns and TiOns, respectively. The devices grown on nanosheets/Pt/Si show significantly improved polarization fatigue properties over those of similar devices grown directly on Pt/Si. The differences in properties are ascribed to differences in the crystalline structures and the density of the films. These results show a route toward the fabrication of single crystal piezoelectric thin films and devices with high quality, long-lifetime piezoelectric capacitor structures on nonperovskite and even noncrystalline substrates such as glass or polished metal surfaces.